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Downsizing Pt-based catalysts to generate a higher surface-to-volume ratio and maximize atom utilization efficiency has been recognized as an effective strategy to achieve high mass activity. However, the synthesis of homogeneous, ultra-small bimetallic nanoclusters remains a significant challenge due to the difficulties in controlling stoichiometry and surface state control, large miscible gaps between different metals and surface state changes induced by the reaction gas environment. In this paper, bimetallic Pt-based nanoclusters such as PtPd, PtRu, PtCu deposited on carbon black (Vulcan XC72R) were fabricated by the reduction of H 2 plasma.The structure and morphology of those prepared catalysts were revealed by HAADF-STEM, HR-TEM, EDS and XPS. The results indicated the prepared Pt-based nanoclusters displayed high dispersibility and small size owning to the non-equilibrium characteristics of non-thermal plasma (NTPs). The average sizes of PtPd, PtRu and PtCu were 2.06 ± 0.68 nm, 3.66 ± 1.34 nm and 1.98 ± 0.7 nm, respectively. Meanwhile, the synthesized PtPd nanoclusters with the ratio of 3:4 exhibited high catalytic activity in the hydrogen evolution reaction (HER). The Pt 3 Pd 4 /VR-P displayed a low overpotential (19 mV) at 10 mA/cm2 and achieved a high mass activity of 5.4 A/mg for HER in 0.5 M H 2 SO 4 solution, which was 13.8 times higher than those of the commercial Pt/C catalysts. Moreover, the Pt 3 Pd 4 /VR-P demonstrated excellent stability with a negatively shifting about 40 mV after 10,000 cycles at a current density of 10 mA/cm2, which was close to that of JM-Pt/C (32 mV). The results prove NTPs technology is effective for the preparation of bimetallic Pt-based nanoclusters. Non-thermal plasma is an innovative method to prepare Pt-based nanoclusters with high dispersibility and small size. The synthesized Pt 3 Pd 4 nanoclusters with an average size of 2.06 ± 0.68 nm displayed a low overpotential (19 mV) at 10 mA/cm2 and achieved a high mass activity of 5.4 A/mg for HER in 0.5 M H 2 SO 4 solution, which was 13.8 times higher than that of the commercial Pt/C catalysts. [Display omitted] • A plasma fabrication technique for synthesis of Pt-based nanoclusters with high dispersibility and small size was developed. • The average sizes of the prepared PtPd, PtRu and PtCu nanoclusters are 2.06 ± 0.68 nm, 3.66 ± 1.34 nm and 1.98 ± 0.7 nm. • The prepared Pt 3 Pd 4 /VR-P exhibits a low overpotential (19 mV) at 10 mA cm−2 and a high mass activity (5.4 A mg−1) for HER. [ABSTRACT FROM AUTHOR]

The gas diffusion layer (GDL) plays an important role in proton exchange membrane fuel cells (PEMFC) to support the catalytic layer, collect the current, conduct the gas and discharge the reaction product water. Titanium (Ti) can be one of the choices of GDL materials due to its high strength, low density and excellent corrosion resistance. Therefore, this paper investigated Ti substrate material for GDL and comparatively analyzed the changes in the contact angle of the GDL before and after hydrophobic treatment, analyzed the changes in the performance of the cell after different treatment processes, and measured the effect of compression force on the contact resistance of the cell. The results show that, after the selection of Ti felt as the substrate and the carbon plating process, the contact angle of the substrate layer and the microporous layer increased significantly, and the hydrophobicity of the GDL surface improved after carbon plating. The contact resistance of the Ti felt substrate was significantly reduced after carbon plating and was even lower than that of the C–H-060 substrate. Considering the importance of the hydrophobicity of GDL, acetylene black microporous layer coating is also needed to increase the contact angle of the GDL interface and improve the hydrophobicity of GDL. The hydrophobic treatment of MPL using Ti felt as the substrate can significantly improve the output performance of the cell at high current density, avoid flooding inside the cell, and increase the current density operating range of the cell. • The contact angle of Ti-GDL before and after hydrophobic treatment was studied. • The performance of Ti-GDL cell after different treatment processes were compared. • The effect of compression force on the contact resistance was analyzed. • The feasibility of Ti as a substrate for GDL in PEMFC was analyzed. [ABSTRACT FROM AUTHOR]

The present study focuses on the cogeneration of hydrogen (H 2) and solid carbon from microwave-driven methane pyrolysis in a fluidized bed of carbon pellets. Numerical simulations using a coupled gas-solid chemistry approach reveal that introducing microwave thermal effects improves methane conversion rate, H 2 selectivity, and carbon deposition rate. The chemical pathways analysis divulges that once the leading reaction for decomposing CH 4 into H 2 , i.e., CH 4 +H ↔ CH 3 +H 2 , is completed, the C 2 H 2 deposition mechanism onto the carbon pellets is the dominant pathway for the solid carbon production, indicating almost no carbon black (i.e., nanoparticles) formation. Carbon pellets provide abundant surface area for the conversion of C 2 H 2 to H 2 , enhancing H 2 selectivity in the resulting products. More importantly, the importance of more complex molecules, such as polycyclic aromatic hydrocarbons, greatly diminishes when using carbon pellets in the pyrolysis process, implying that smaller kinetic mechanisms are equally effective and desirable. • Cogeneration of H 2 and carbon from microwave-driven methane pyrolysis is studied. • Reaction CH 4 +H ↔ CH 3 +H 2 is the leading reaction in decomposing CH 4 and producing H 2. • Almost 100% of solid carbon comes from the addition of C 2 H 2 on the carbon pellets. • Carbon pellets suppress the formation of PAHs, resulting in no carbon black. • Microwave thermal effects exhibit positive impacts on H 2 and carbon production. [ABSTRACT FROM AUTHOR]

To understand the effects of additives on the properties of rubber grades suitable for sealing applications in high-pressure H 2 gas infrastructure, five acrylonitrile butadiene rubber (NBR) vulcanizates with different fillers and curing agents are investigated. Structure-property relationships of these grades are correlated with the additives and properties required for high-pressure gas atmospheres are evaluated. Further, the influence of the exposure to high-pressure hydrogen, i.e., hydrogen uptake and morphological changes after exposure, is evaluated. With the addition of a silica filler and a coupling agent for improved filler-matrix interfaces, similar overall properties, e.g. crosslink density, tensile strength, and storage modulus are obtained, compared to a carbon black (CB) filled grade. Density reduction after hydrogen exposure is significantly higher for CB-filled NBR, indicating higher hydrogen uptake in CB-filled rubber compared to silica filled NBR grades, or slower gas desorption. However, CB-filled specimens show to be less prone to filler migration than the silica-filled samples. • Effects of NBR formulations on properties for high-pressure gas systems were tested. • Functionalized silica enhances typical properties to a comparable range like CB. • The balance of additives results in suitable RGD performance. • Silica filled NBR shows lower H 2 uptake compared to non-plasticized CB filled NBR. • Morphology of CB filled NBR is less affected by H 2 than silica filled grades. [ABSTRACT FROM AUTHOR]

Bioelectro-Fenton (BEF) utilizes microorganisms to generate electrons at the anode and transfer them to the cathode via an external circuit to generate hydrogen peroxide (H 2 O 2) and drive the Fenton reaction to produce OH•. Response surface methodology was used to optimize the ratio of nano zero-valent iron-containing biochar and conductive carbon black (nZVI-biochar/CCB) with the chitosan-coated on the surface of the cathode material to promote H 2 O 2 production and reduce the internal resistance of the BEF system. The BEF system using the optimized cathode catalysts showed a 2.6-fold increase in power density and a 2.03-fold increase in open-circuit voltage over the BEF reaction using graphite felt cathodes only. This finding demonstrated that the optimized cathode improved the capability of the cathode to receive electrons. The BEF system with the optimized cathodic catalyst completely removed 400 mg/L isopropanol within 24 h, and the treated wastewater was almost nonbiotoxic. [Display omitted] • Microbial fuel cells produce electricity to drive the electro-Fenton (EF) process. • Bioelectro-Fenton (BEF) process removes isopropanol from wastewater. • Optimization of cathodic catalyst ratio improves H 2 O 2 generation in the EF system. • BEF system with optimized cathodic catalyst enhances power and isopropanol removal. [ABSTRACT FROM AUTHOR]

Dodecahydro-N-ethylcarbazole (12H-NEC) is considered as a highly promising liquid organic hydrogen carrier, but its commercial application is constrained by the requirement of large amounts of precious metal catalysts for dehydrogenation. Herein, Pd nanoclusters with an average particle size of 1.1 nm supported on amine groups modified carbon blacks (Pd/N–C HNO3) are developed to efficiently catalyze the dehydrogenation of 12H-NEC with a low loading of Pd (2.2 wt%, 0.12 mol%). Induced by the nitrogen doping in the carbon black, the d- band center of the Pd (111) surface shifts from −1.64 eV to −1.53 eV, resulting in the electron-deficient structure of thus-formed Pd nanoclusters owing to the electron transfer from Pd to N atoms and uniform distribution of Pd nanoclusters inside of carbon blacks. This electron transfer effectively tunes Pd0:Pdδ+ ratio for enhancing the adsorption of reactant species of 12H-NEC on the surface of Pd nanoclusters and hence facilitates the catalytic role of Pd nanoclusters in enhancing the hydrogen desorption performance of 12H-NEC. As a result, every step of the dehydrogenation of 12H-NEC under the catalysis of Pd nanoclusters on the nitrogen-doped support exhibits lower ΔG values compared to the non-doped support, which provides direct evidence to the important role of the nitrogen doping of the catalyst support in improving the dehydrogenation performance of 12H-NEC on the Pd surface. Therefore, a hydrogen release capacity of 5.60 wt% with 100% conversion and a selectivity of 90% could be obtained for 12H-NEC under the catalysis of Pd nanoclusters supported on amine-functionalized carbon black at 453 K with a low precious metal dosage (0.12 mol%). [Display omitted] •Pd nanoclusters with an average particle size of 1.1 nm supported on amine groups modified carbon blacks are developed. • A hydrogen release capacity of 5.60 wt% is obtained for 12H-NEC with an ultralow Pd dosage (0.12 mol%). • A H 2 release amount of 5.49 wt% with a capacity retention of 96% is achieved for 12H-NEC after five cycles for 40 h. • The d- band center of the Pd (111) surface shifts from −1.64eV to −1.53eV upon nitrogen doping. • DFT calculations reveal that ΔG for the dehydrogenation of 12H-NEC by the catalyst is decreased upon nitrogen doping. [ABSTRACT FROM AUTHOR]

Low-carbon conversion of hydrocarbon fuels and feedstocks, as well as the macroscopic production of H 2 , are central focus in the advancement of high-value and efficient conversion of CH 4. The effects of Ar addition ratio, discharge power and temperature on the results of plasma methane cracking were investigated on a dielectric barrier discharge (DBD) plasma experimental system. The results show that the addition of Ar can improve the methane conversion, and the optimal ratio of CH 4 conversion to H 2 production after the effect is CH 4 : Ar = 1:1, at which the methane conversion reaches 49.62% and the H 2 selectivity reaches 52.66%. The plasma at 25 °C can make the methane conversion close to the effect of catalytic cracking at 600 °C, while the H 2 selectivity is lower, the H 2 generation is 32.59% lower than the latter, and the products have more C 2 –C 4 hydrocarbon impurities. The solid byproduct resulting from the DBD plasma cracking of methane primarily consisted of carbon black, possessing an average particle size of 62.21 nm. The incorporation of Ar and the amplification of power augment the CH* radical intensities, which suggests both conditions contribute positively to the dissociation of the CH 4 molecule. [Display omitted] • The optimal ratio of CH 4 to Ar stands at 1:1. • Plasma operating at 25 °C can mimic the catalytic thermal cracking effect at 600 °C. • The generation of the solid-phase product, carbon black is induced by the plasma. • An increase in the C 2 –C 4 product is observed under plasma activity. [ABSTRACT FROM AUTHOR]

A reliable and compact chemical mechanism of gas-phase methane pyrolysis leading to formation of large polycyclic aromatic hydrocarbon (PAH) molecules has been developed. This model is designed for studies of carbon nanostructure synthesis such as carbon black and graphene flakes, including soot growth kinetics. Methane pyrolysis with carbon nanostructure synthesis is a two-stage process where conversion of CH 4 to C 2 H 2 precedes the growth of PAH molecules from acetylene. We present a single chemical mechanism that accurately describes both stages. We have constructed a compact and accurate chemical mechanism capable of modeling both stages of methane pyrolysis based on the ABF [1] mechanism which was expanded with the most prominent reaction pathways from the mechanism by Tao [2] for small PAH molecules and HACA pathways for larger PAH molecules, up to 37 aromatic rings. The resulting mechanism was validated through comparison to multiple available sets of experimental data. Good agreement with the experimental data for both processes was obtained. Performance of the mechanism was tested for pyrolysis of methane-rich mixtures under long residence times leading to abundant formation of PAH molecules. It is shown that the inclusion of larger PAH species (up to A37) in the chemical mechanism is important for accurate prediction of the fraction of carbon converted to PAH molecules and, correspondingly, the residual fraction of acetylene in the mixture. The mechanism file is available upon request. [Display omitted] • Compact and accurate chemical mechanism for methane pyrolysis was assembled. • The mechanism covers both stages of methane pyrolysis: formation of C 2 H 2 and PAH. • The mechanism incorporates large PAH molecules up to 37 aromatic rings (A37). • Good agreement with the experimental data was obtained. [ABSTRACT FROM AUTHOR]

Developers of direct carbon fuel cell (DCFC) technology seek to convert carbon to a pure or highly concentrated carbon dioxide stream that could ultimately be transported and sequestered. Carbon black produced by natural gas cracking processes is very pure and is therefore a candidate for use in DCFCs. In this study the performance of As received and Treated carbon blacks are compared in a planar cell configuration. At a more viable operating temperature of 750 °C, the As received carbon was found to produce a peak power density of 51 mW/cm2 at a current density of 104 mA/cm2. The performance then increased to 105 mW/cm2 at a current density of 145 mA/cm2 at 850 °C. Acid treatment of the carbon was found to improve performance of the DCFC at 750 °C by 35% (69 mW/cm2 at 160 mA/cm2) and only by 5% at 850 °C (111 mW/cm2 at 201 mA/cm2). • A commercial carbon black was used to fuel a planar, direct carbon fuel cell (DCFC). • An acid treatment method applied to the carbon black increased its wettability. • A DCFC output higher power density with Treated than with As received carbon black. [ABSTRACT FROM AUTHOR]

A method for producing hydrogen from liquid benzene without CO 2 generation using plasma is proposed. A liquid plasma was emitted from the liquid reactant to crack liquid benzene to produce hydrogen. The only gaseous product was H 2 and no CO 2 was formed. Carbon crystals were produced as a solid product. To increase the decomposition efficiency of liquid benzene and the efficiency of hydrogen production, perovskite was applied as a catalyst. The reaction produced nano-sized carbon particles with hydrogen as the main product without impurities. The crystal size of carbon black was very small (<10 nm) and uniform. The carbon products were similar in crystal shape and size regardless of the reaction time. Liquid benzene is decomposed by active species in the liquid plasma to produce hydrogen and carbon without catalyst injection. When the perovskite catalyst was applied to the reaction using liquid plasma, the hydrogen production rate and carbon yield were significantly increased. Liquid benzene simultaneously produces hydrogen and carbon black through a decomposition reaction by liquid plasma. The LPP cracking process of liquid benzene can be evaluated as a 'green hydrogen' production technology that does not generate CO 2. [Display omitted] • A method was proposed for producing hydrogen from the decomposition of benzene using plasma. • Liquid benzene was decomposed into hydrogen and carbon by liquid plasma and photocatalyst. • Perovskites were applied as a photocatalyst to increase hydrogen production efficiency. • The products were hydrogen gas and carbon nanoparticles in this reaction, no CO 2 is formed. • Application of the perovskite catalyst significantly increased hydrogen production and carbon yield. [ABSTRACT FROM AUTHOR]

The synthesis of ammonia via electrochemical nitrogen reduction reaction (NRR) provides an attractive alternative approach to the traditional Haber-Bosch process. In this regard, a one-step hydrothermal method was adopted to synthesize a bimetallic oxide， ferric molybdate (Fe 2 (MoO 4) 3), coated with carbon black on the surface (denoted as Fe 2 (MoO 4) 3 /C). The carbon black coating minimizes aggregation of Fe 2 (MoO 4) 3 , leading to increased electrochemical active sites for NRR. Additionally, this coating improves the electrical conductivity of Fe 2 (MoO 4) 3 thereby accelerating electron transfer between carbon black and Fe 2 (MoO 4) 3 , which is beneficial to charge transfer and enlarge the electrochemical active surface areas. At a potential of −0.4 V RHE (vs. reversible hydrogen electrode, RHE), the ammonia yield achieved was up to 51.76 μg h−1 mg cat −1, with a Faradaic efficiency of 90.63% at −0.35V RHE. Impressively, this electrocatalyst exhibited excellent cycle stability and durability. Fe 2 (MoO 4) 3 /C electrocatalyst was prepared via a one-step hydrothermal method and demonstrated to be a highly efficient non-noble metal catalyst towards electrocatalytic NRR. The obtained Fe 2 (MoO 4) 3 /C gives an NH 3 yield rate of 51.76 μg h−1 mg cat −1 at −0.4 V RHE and FE of 90.63% at −0.35 V RHE in 0.1 M Na 2 SO 4 solution, which is much higher than that of the contrast Fe 2 (MoO 4) 3 sample. [Display omitted] • Fe 2 (MoO 4) 3 /C composite electrocatalyst is reasonably designed and synthesized. • Fe 2 (MoO 4) 3 /C shows excellent stability for electrocatalytic nitrogen reduction in 0.1 M Na 2 SO 4 electrolyte. • The excellent NRR activities of Fe 2 (MoO 4) 3 /C own to the enhanced electron transfer and enlarged ECSA. [ABSTRACT FROM AUTHOR]

A Pd–Ni ellipsoidal nano-alloy catalyst with a long diameter of 5 ± 0.1 nm and short diameter of 3 ± 0.1 nm supported on carbon black (PdNi EN/CB) was successfully prepared via a facile one-pot synthesis route. During the synthetic process, cetyl trimethyl ammonium chloride (CTAC) was used as a structure-directing agent, which induced the ellipsoidal morphology. As compared with commercial Pt/C, Pd/C and Pd–Ni catalyst without special morphology supported on carbon black (PdNi NW/CB), PdNi EN/CB demonstrated both ultrahigh catalytic activity towards oxygen reduction reaction (ORR) and favorable long-term durability in alkaline solutions. According to X-ray photoelectron spectra (XPS) analysis and density functional theory (DFT) calculation results, a down-shift of the Pd d-band center, which weakens the adsorption strength for oxygen-containing species, along with a reaction path closer to the ideal free energy due to the small particle size and special morphology of Pd–Ni ellipsoidal nano-alloys contribute to the excellent activity of the PdNi EN/CB catalyst. [Display omitted] • A Pd–Ni ellipsoidal nano-alloy catalyst supported on carbon black was prepared. • Formation of ellipsoid is due to the addition of CTAC as a structure-directing agent. • PdNi EN/CB has superb catalytic activity for ORR and favorable durability in KOH. • A down-shift of d-band center owing to special morphology leads to the high activity. • The reaction path of PdNi EN/CB is closer to the ideal free energy. [ABSTRACT FROM AUTHOR]

Hydrogen-based economy has a great potential for addressing the world's environmental concerns by using hydrogen as its future energy carrier. Hydrogen can be stored in gaseous, liquid and solid-state form, but among all solid-state hydrogen storage materials (metal hydrides) have the highest energy density. However, hydrogen accessibility is a challenging step in metal hydride-based materials. To improve the hydrogen storage kinetics, effects of functionalized catalysts/dopants on metal atoms have been extensively studied. The nanostructuring of metal hydrides is a new focus and has enhanced hydrogen storage properties by allowing higher surface area and thus reversibility, hydrogen storage density, faster and tunable kinetics, lower absorption and desorption temperatures, and durability. The effect of incorporating nanoparticles of carbon-based materials (graphene, C60, carbon nanotubes (CNTs), carbon black, and carbon aerogel) showed improved hydrogen storage characteristics of metal hydrides. In this critical review, the effects of various carbon-based materials, catalysts, and dopants are summarized in terms of hydrogen-storage capacity and kinetics. This review also highlights the effects of carbon nanomaterials on metal hydrides along with advanced synthesis routes, and analysis techniques to explore the effects of encapsulated metal hydrides and carbon particles. In addition, effects of carbon composites in polymeric composites for improved hydrogen storage properties in solid-state forms, and new characterization techniques are also discussed. As is known, the nanomaterials have extremely higher surface area (100–1000 time more surface area in m2/g) when compared to the bulk scale materials; thus, hydrogen absorption and desorption can be tuned in nanoscale structures for various industrial applications. The nanoscale tailoring of metal hydrides with carbon materials is a promising strategy for the next generation of solid-state hydrogen storage systems for different industries. [Display omitted] • The importance of tunability of Metal hydrides are discussed. • Summarized the effect of integrating carbon-based materials on Metal hydrides. • Presented synthesizing strategies for Metal hydrides and carbon-based materials. • Highlighted comparative summary of the characterization techniques. [ABSTRACT FROM AUTHOR]

The microporous layer (MPL) as a part of diffusion medium has an important impact on mass transfer of proton exchange membrane fuel cell (PEMFC). In this study, MPLs of gas diffusion layers (GDLs) are prepared with different carbon blacks, and the properties of carbon blacks and their effects as MPLs on cell performance are systematically investigated. The results show that the GDL prepared by Acetylene Black (ACET) exhibits the best performance with a maximum power density up to 2.05 W cm−2. Moreover, it still maintains extremely high performance with increasing current density even at humidity condition of 100% relative humidity, which means its excellent water/gas transportation capacity. This study contributes to deeply understanding the correlations between the properties of MPL material itself and their corresponding performance exhibited in cell. It also provides an important reference for enhancing cell performance and further advancing the practical applications of MPLs in PEMFC field. [Display omitted] • This paper focus on the selection and optimization of MPL materials. • The physical characteristics of different GDLs are systematically compared. • Pore size distribution and surface wettability of GDLs are two key characteristics. • Properties of carbon blacks and their effects on cell performance are studied. [ABSTRACT FROM AUTHOR]

Graphene has been proposed as support or as co-support for Proton Exchange Membrane Fuel cells (PEMFCs) electrocatalysts due to its high electronic conductivity, corrosion stability and high specific surface area compared to common carbon blacks, such as Vulcan. Despite such outstanding properties, comprehensive studies on long-term stability of graphene-supported Oxygen Reduction Reaction (ORR) catalysts are still unavailable or limited. The stability of graphene as support is now studied and compared with carbon black in terms of electrochemical performance and degradation mechanisms. Catalytic layers with Pt/G were prepared and subjected to a set of three different Accelerated Stress Tests (ASTs): cycling at high potentials, Open Circuit Potential (OCP) holding and cycling at low potentials. This study aims to assess if and why graphene is a better candidate as support. The Pt/G catalyst outperformed the reference catalyst in all ASTs, delivering both higher electrochemical active surface area (ECSA) and ORR mass-specific activity. Such electrochemical performance was correlated with morphological evidences associated to the support itself and with Pt nanoparticles. • Stability of Pt/G was studied via three different degradation protocols and compared to Pt/H. • Potential cycling below 1 V promotes higher ORR mass-specific activity loss, among all ASTs. • Pt/G maintained higher ECSA and ORR activity than Pt/H upon the different types of ASTs. • Pt/G is considerably more stable than Pt/H despite observing a higher particle growth. [ABSTRACT FROM AUTHOR]

For hydrogen to be successfully used as an energy carrier in a new renewable energy driven economy, more efficient hydrogen storage technologies have to be found. Solid-state hydrogen storage in complex metal hydrides, such as sodium alanate (NaAlH 4), is a well-researched candidate for this application. A series of NaAlH 4 /mesoporous carbon black composites, with high NaAlH 4 content (50–90 wt%), prepared via ball milling have demonstrated significantly lower dehydrogenation temperatures with intense dehydrogenation starting at ∼373 K compared to bulk alanate's ≥ 456 K. Dehydrogenation/hydrogenation cycling experiments have demonstrated partial hydrogenation at 6 MPa H 2 and 423 K. The cycling experiments combined with temperature-programmed dehydrogenation and powder X-ray diffraction have given insight into the fundamental processes driving the H 2 release and uptake in the NaAlH 4 /carbon composites. It is established that most of the hydrogenation behavior can be attributed to the Na 3 AlH 6 ↔ NaH transition. [Display omitted] • Low to moderate carbon content strongly affects the H 2 storage properties of NaAlH 4. • Intense H 2 evolution already at ∼373 K. • Partial hydrogenation was achieved at mild conditions: 423 K and 6 MPa H 2. • Changes in material properties attributed to nanoscaling via mesoporous carbon black. • (De)hydrogenation cycling attributed mainly to the Na 3 AlH 6 ↔ NaH transition. [ABSTRACT FROM AUTHOR]

The sluggish kinetics of oxygen-evolution reaction (OER) through water-oxidation reaction results in high overpotentials for water splitting. Among different compounds, carbon-based material/Mn oxide composites were reported as OER catalysts. Fullerene soot (FS), which contains a mixture of fullerenes and carbon blacks, is low-cost compared to fullerenes and is commercially available. Herein, the Mn oxide/fullerene soot (MnO x /FS) composite was investigated as an OER catalyst under neutral conditions. The composite was prepared through the reaction of KMnO 4 and FS as a facile, easy, and low-cost procedure. In this method, amorphous Mn oxide is formed directly on FS. The material was characterized by a number of methods. Then, the OER catalytic activity of MnO x /FS was studied in a LiClO 4 solution (pH ≈ 6.3). Compared to pristine FS, the OER activity of MnO x /FS is 2.5 times higher at 2.25 V vs. RHE. The Tafel slopes for OER are 450 and 240 mV per decade for FS and the reported composite, respectively. [Display omitted] A simple strategy to synthesize Mn oxide/fullerene soot as a catalyst for the oxygen-evolution reaction through water-oxidation reaction under neutral conditions is reported. • An Mn oxide/fullerene soot (FS) composite was prepared through the reaction of KMnO 4 and FS. • The composite was introduced as a promising catalyst for water-oxidation reaction. • In the composite, fullerene soot acts as conductive support, and MnO x acts as a catalyst. [ABSTRACT FROM AUTHOR]

Large scale, low cost, and low carbon intensity hydrogen production is needed to reduce emissions in the energy and transportation sectors. We present a techno-economic analysis and life cycle assessment of natural gas pyrolysis technologies for hydrogen production, with carbon black (CB) as a co-product. Four designs were considered based on the source of heat to the pyrolysis system, the combustion medium, and use of carbon capture (CC) technology. The oxygen-fired-CB design with CC is the most attractive from financial and environmental perspectives, superior to a conventional steam methane reformer (SMR) process with CC. The estimated pre-tax minimum hydrogen selling prices for the pyrolysis technologies range between $1.08/kg and $2.43/kg when natural gas (NG) costs $3.76/GJ. Key advantages include near-zero onsite GHG emissions of the oxygen-fired-CB design with CC and up to 41% lower GHG emissions compared to the SMR + CC process. The results indicate that natural gas pyrolysis may be a feasible pathway for hydrogen production. • Commercial scale hydrogen production via natural gas pyrolysis pathways is explored. • Options for handling the carbon black product are examined. • Low-carbon hydrogen of $1.7/kgH 2 outperforms the SMR hydrogen at similar conditions. • Cradle to gate GHG emissions between 1.8 and 4.6 kgCO 2 eq/kgH 2 is computed. [ABSTRACT FROM AUTHOR]

A facile, single step microwave assisted polyol route for simultaneously depositing platinum as well as co-doping graphene oxide, is herein proposed. However, low durability and full cell performance of Pt/NPG (platinum deposited on nitrogen phosphorous co-doped graphene) was observed due to restacking of graphene layers. This issue was addressed by intercalating CB into the graphene layers as spacers during the synthesis (in-situ addition of spacers - Pt/(NPG + S)). Moreover, to study the influence of spacers, external addition of spacers (ex-situ - Pt/(NPG) + S) were also examined. Results from our study indicate that in-situ addition of spacers- Pt/(NPG + S) enhanced the full cell performance (405 mW cm−2) and exhibited <40% ECSA loss (37.47%), thereby attaining DoE target. Thus, emerging as a durable cathode electrocatalyst (Pt/(NPG + S)) for PEM fuel cells. [Display omitted] • Microwave irradiation of Pt deposition and N & P co-doping (one-step process). • Effect of Vulcan as spacer in graphene re-stacking. • Electrocatalyst subjected to DoE protocols for durability. • Pt/(NPG + S) exhibits better durability (37.47%). • Full cell performance has been studied on synthesized electrocatalyst. [ABSTRACT FROM AUTHOR]

A novel thermal plasma process was developed, which enables economically viable commercial-scale hydrogen and carbon black production. Key aspects of this process are detailed in this work. Selectivity and yield of both solid, high-value carbon and gaseous hydrogen are given particular attention. For the first time, technical viability is demonstrated through lab scale reactor data which indicate methane feedstock conversions of >99%, hydrogen selectivity of >95%, solid recovery of >90%, and the ability to produce carbon particles of varying crystallinity having the potential to replace traditional furnace carbon black. The energy intensity of this process was established based on real-time operation data from the first commercial plant utilizing this process. In its current stage, this technology uses around 25 kWh per kg of H2 produced, much less than water electrolysis which requires approximately 60 kWh per kg of H2 produced. This energy intensity is expected to be reduced to 18–20 kWh per kg of hydrogen with improved heat recovery and energy optimization. [Display omitted] • A methane pyrolysis plasma process for high value carbon and hydrogen is presented. • Methane feedstock conversions of >99% were achieved. • Hydrogen selectivity of >95% was achieved. • Solid recovery of >90% was achieved. • Energy intensity of the first commercial plant is 25 kWh per kg of H2 produced. [ABSTRACT FROM AUTHOR]

The influence on the decomposition and reforming of the hydrogen storage material NaAlH 4 by adding relatively low amounts of mesoporous carbon black is investigated with in situ diffraction. A 60:40 NaAlH 4 /carbon black composite is prepared via ball milling and characterised ex situ via X-ray diffraction, gas adsorption, temperature-programmed decomposition, and dehydrogenation/hydrogenation cycling methods. The prepared composite is deuterated, and the crystalline phase composition is determined with in situ neutron powder diffraction method during multiple decomposition/deuteration cycles. Changes in the crystalline phase composition start slightly below the melting temperature of the pristine alanate, whereas the release of deuterium starts at considerably lower temperatures. The decomposition of Na 3 AlD 6 to NaD is almost completely reversible at the applied low deuterium pressures of ≥2 MPa. Thus, the strong effect of even low concentrations of a mesoporous carbon black on the capability to store H 2 reversibly is showcased and analysed in-depth. [Display omitted] • NaAlD 4 confined in a mesoporous carbon black. • In situ neutron powder diffraction during dedeuteration/deuteration cycles. • Crystalline composition determination at all experimental instances. • D 2 release at highly lowered temperatures from small-particulate/amorphous phase. • Full regeneration of Na 3 AlD 6 from NaD at low deuterium pressures (≤20 bar). [ABSTRACT FROM AUTHOR]

Considering the disadvantages of conventional compressors, which are widely used in the world, it is thought that the electrochemical hydrogen purifier and compressor system (EHPC) to be developed will provide great advantages in hydrogen technologies. The electrocatalyst, which is one of the main components of the EHPC system, is critical for both the performance and applicability of the system. In this study, commercial carbon black supported Pt and Pd containing catalysts were prepared for the EHPC system by using microwave heating method. The synthesized catalysts were mono and bimetallic and were named as Pt/C, Pd/C and PtPd/C, respectively. By characterizing the prepared catalysts with ICP-MS, SEM-EDS, TEM, XRD and XPS, information about the distribution, amount, morphology and composition of metal nanoparticles on the support material was obtained. In addition, electrochemical properties of the catalysts were determined by CV analysis. The physical characterization results revealed that the catalysts were successfully synthesized by microwave method and that different ratios of metals and bimetallic could be loaded on the support material. It was also seen that the electrochemical activity of the PtPd/C bimetallic catalyst was better than the others. [Display omitted] • Catalyst is critical in electrochemical hydrogen purification-compression systems. • Mono and bimetallic catalysts were prepared by microwave heating method. • HER/HOR performances were evaluated for their electrochemical activities. • Bimetallic PtPd/C catalyst showed superior performance than the others. [ABSTRACT FROM AUTHOR]

Developing novel oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) catalysts is vital for water splitting. Here, carbon black (CB) and nickel carbonyl powder (NCP) are used as components, and the nonionic surfactant polyvinyl pyrrolidone (PVP) is used as a shape-controlled capping agent to easily prepare layered double (Ni, Fe) hydroxide (NiFe-LDH) electrodes. Scanning electron microscopy observation and X-ray photoelectron spectra analysis show that the Fe2+-doped layered double hydroxide is grown in situ on nickel foam (NF). CB (XC-72) and NCP further improve the electrical conductivity. At 10 mA•cm−2, the overpotentials of the OER and HER are 203 mV and 83 mV, respectively, in 1 M KOH. Only 1.48 V is needed when both electrodes are applied for water splitting, and it has a stability of more than 100 h. This work can be used as a medium to elevate the OER and HER performance of NiFe-LDH-based catalysts. [Display omitted] • The NiFe-LDH@NCP+CB (PVP 0.3) electrode is prepared by a simple hydrothermal method. • The addition of conductive carbon black (CB) significantly reduces the impedance of the material. • The addition of nickel carbonyl powder (NCP) in the layer improves the OER and HER activities of NiFe-LDH@NCP+CB (PVP 0.3). • Low potential (1.48 V@10 mA cm−2) and long-term circulation (100h) for overall water splitting is achieved. [ABSTRACT FROM AUTHOR]

Single atom catalysts (SACs) can improve the efficiency of oxygen evolution reaction (OER). However, metal SACs anchored on carbon materials are relatively uncommon for the OER. In this paper, using carbon black as carrier, NiFe SACs are fabricated by one step pyrolysis method. When the weight ratio of Ni/Fe is lower than 5:3, NiFe@C exibits highly-dispersed SACs over carbon in addition to some Ni 3 Fe alloy. The prepared NiFe@C 5:3 SACs showed excellent OER performance with an overpotential of 322 mV and 438 mV for current density of 10 mA/cm2 and 100 mA/cm2, respectively. The Tafel slope of NiFe@C 5:3 was as small as 87.6 mV/dec, indicating fast charge transfer of NiFe@C 5:3 during OER process, which was also confirmed by electrochemical impedance spectra with R ct = 18.07 Ωcm2. Meanwhile, NiFe@C 5:3 had the highest specific capacitance of 5 mF/cm2 with good stability. This work provides a reference for designing electocatalyst material for efficient, stable and economical OER process. • NiFe SACs are fabricated by pyrolysis method. • NiFe@C 5:3 exibits highly dispersed SACs on carbon. • The required over potential of NiFe@C 5:3 for current density 10 mA/cm2 is only 322 mV. • This work provides a reference for designing electocatalyst material. [ABSTRACT FROM AUTHOR]

The water discharge capability of the gas diffusion layer (GDL) in a proton exchange membrane fuel cell (PEMFC) is dominantly influenced by the capillary pressure gradient. In this study, three different microporous layer (MPL) manufacturing methods are applied to improve the capillary pressure gradient in the MPL and, consequently, improve the water discharge capability of the GDL. Firstly, the GDL is manufactured by varying the thickness of the MPL. Secondly, hydrophilic carbon black particles are additionally added to the main carbon black particles of the MPL. Finally, different GDLs are fabricated by varying the number of MPL loadings with different viscosities on one side of the substrate. At 100% relative humidity (RH) and a current density of 2.1 A/ cm 2 , the GDL with a thinner MPL yields 31.9% higher performance than that with a thicker MPL; furthermore, the GDL with the hydrophilic carbon black particles yields 7.2% lower performance than that without the hydrophilic carbon black particles treatment at 100% RH, but the GDL with hydrophilic carbon black particles shows 3.9% higher performance at 30% RH. The GDL loaded with a low-viscosity MPL on top of a high-viscosity MPL demonstrates 81.8% higher performance than that loaded with a low-viscosity MPL alone. • Effects of microporous layer manufacturing methods. • Effects of a thickness of the microporous layer. • Effects of addition of hydrophilic carbon black to microporous layer. • Effects of number of the microporous layer loadings onto the substrate. • Effects of each experimental variable on the capillary pressure gradient. [ABSTRACT FROM AUTHOR]

In order to reduce greenhouse gas emissions and ensure the transition to hydrogen economy, the development of new carbon-neutral technologies is required. One of the possible technologies is the detonation decomposition of acetylene with the simultaneous production of hydrogen and carbon black with a minimal emission of carbon monoxide. Acetylene for this purpose can be obtained by various methods, including plasma conversion of methane without CO 2 emission. This paper presents the results of experiments on the production of hydrogen and carbon black in the form of Nanoscale Detonation Carbon (NDC) on a laboratory version of the Pulse Gas-Detonation Device. This apparatus can produce 1.7 kg of hydrogen and 17.7 kg of NDC per hour. • Acetylene as an intermediate product between methane and hydrogen. • Detonation of fuel-rich acetylene-oxygen mixtures. • Detonation excitation at atmospheric pressure. • Hydrogen obtained together with carbon black. • Carbon footprint reduction. [ABSTRACT FROM AUTHOR]

The resistance of the cathode oxygen reduction reaction in polymer electrolyte fuel cells must be reduced for improving the performance. Therefore, it is important to thoroughly understand the relationship between the heterogeneous structures and the cell performance. However, it is difficult to obtain such an understanding using experimental approaches and typical uniform porous simulations. In this study, numerical analysis was used to simulate a three-dimensional catalyst layer (CL) with carbon black (CB) aggregate structures and ionomer coating models, and a cathode reaction and mass transport simulation model incorporating the heterogeneous structure was developed. Moreover, the relationship between the electrode structure and the cell performance, including the reaction distribution and output performance, was examined. The current density distribution depended on the CB structure and ionomer adhesion shape. From the viewpoint of enhancing both the Pt utilization and the mass transport performance, an adequate heterogeneous pore structure in the CL is necessary. These results were used to determine the optimal material properties for the high performance cell. • Simulation model in cathode catalyst layer with 3D structure was developed. • Heterogeneous structure with carbon black and ionomer was simulated. • Ionomer adhesion affect mass transport, and it cause reaction distribution. • Local reaction on Pt surface was changed to bi-modal distribution by agglomerate. • Effective Pt utilization in cathode was estimated by this simulation. [ABSTRACT FROM AUTHOR]

The effect of electrode spacing on a soil microbial fuel cell (MFC) performance under fed-batch treatment with synthetic urine medium (SUM) was investigated at 2, 5, and 8 cm electrode spacing. The electrodes consisted of stainless-steel mesh with coarse layers of carbon-black. The MFCs were fed with SUM when the natural substrate of the medium was exhausted. Initial feeding resulted in 79.6, 108.7, and 103.1% increase in OCV with a proportional percentage increase in power at 2, 5, and 8 cm electrode spacing. Six days after the first feeding, the power was 189.9, 150.7, and 108. 5 mW/m2 in ascending order of electrode spacing. With more extended treatment, the overall maximum power was obtained at 8 cm spacing. In ascending order of electrode spacing, the highest power (207.92, 263.38, and 271.1 mW/m2) was obtained on days 39, 42, and 93, respectively. The study shows that a larger anode-to-cathode distance requires a longer time for the soil MFC to achieve stable and maximum performance in fed-batch operation. [Display omitted] • Soil MFC is optimized for efficient substrate utilization and long-term sustainable power generation. • The effect of long-term fed-batch operation on the MFC performance with varying electrode spacing is investigated. • Soil MFC performance stability is time dependent on electrode spacing under fed-batch operation. • Smaller electrode spacing results in initially better performance due to lower internal resistance. • Larger electrode spacing takes a longer time for the MFC to reach stable and maximum performance. [ABSTRACT FROM AUTHOR]

In this research, we conducted water electrolysis experiments of a carbon black (CB) based sodium sulfate electrolyte using a Hoffman voltameter. The main objective was to investigate hydrogen production in such systems, as well as analyse the electrical properties and thermal properties of nanofluids. A halogen lamp, mimicking solar energy, was used as a radiation source, and a group of comparative tests were also conducted with different irradiation areas. The results showed that by using CB and light, it was possible to increase the hydrogen production rate. The optimal CB concentration was 0.1 wt %. At this concentration, the hydrogen production rate increased by 30.37% after 20 min of electrolysis. Hence, we show that using CB in electrolytes irradiated by solar energy could save the electrical energy necessary for electrolysis processes. • Successfully prepared a stabilized sodium sulfate electrolyte with carbon black nanoparticles. • Hydrogen production increases with the increasing of the concentration of nanofluids then decrease. • Carbon black nanoparticles have both positive and negative impacts on electrolysis. • Using nanofluids can increase the efficiency of electrolysis. [ABSTRACT FROM AUTHOR]

To develop sealing materials for high-pressure hydrogen devices, the effects of filler type and amount on the hydrogen uptake and volume expansion of rubber composites were evaluated up to 90 MPa. The amount of hydrogen in the rubber matrix and carbon black was elucidated using nuclear magnetic resonance, and the hydrogen elimination behavior of the composites was analyzed by thermal desorption analyses. As hydrogen physically adsorbed on carbon black, the hydrogen uptake of carbon black-filled composites increased. The hydrogen uptake of the composites filled with nonabsorbent silica was smaller, depending on the weight fraction of silica. The ratio of volume expansion to the amount of hydrogen in the matrix of carbon black-filled composites was suppressed by the reinforcement effect of carbon black, which did not expand with hydrogen uptake. The suppression of silica-filled composites was limited by the volume fraction of silica. [Display omitted] • Types & amount of fillers in rubber exposed to high-pressure hydrogen was evaluated. • State of penetrated hydrogen in CB filled rubber composites was evaluated with 1H NMR. • An equation to calculate hydrogen uptake of rubber with varied fillers was driven. • CB reinforced the composites restraining volume expansion, whereas silica did not. • Molecular weight between cross-links is a dominant parameter of the volume expansion. [ABSTRACT FROM AUTHOR]

A series of bed collapse tests were conducted for determining the dense fluidization flow rate of a gas-solid mixture in a micro-channel fluidized bed reactor, and a separate simulation was created for calculating the reactor conversion and temperature of the catalytic methane pyrolysis. The minimum fluidization and minimum bubbling flow rates were determined to be 3.04 and 8.07 sccm for a 2 × 4 mm2 reactor channel with an average voidage of 0.57; 6.21 and 15.9 sccm for a 4 × 6 mm2 channel with an average voidage of 0.42, respectively. By building a correlation between these critical velocities and the cross-sectional area of the fluidized bed reactor channel, the dense fluidization flow rate at the micro-/mini-channel level with an internal diameter range from 0.3 to 1 mm is predicted between 1.47 to 4.21 sccm. In the simulation, an internal diameter of 0.6 mm, a 10-kW solar input rate, and an initial gas flow rate from 0.08 to 0.23 sccm that expands to 1.5–4.3 ccm at the reaction temperature, are considered as the optimal conditions to maintain a reasonable conversion of methane pyrolysis and to keep the mixed fluid in the dense fluidization within the laminar flow range. The conversion of 79% under these conditions was calculated numerically and found to be promising compared to literature reports. An additional force analysis on a single carbon black particle is shown with different reactor orientations to validate the experimental data and simulation results. [Display omitted] • Investigated a novel solar methane pyrolysis scheme in a micro fluidized bed reactor. • Obtained flow rate thresholds of critical fluidization in different channel sizes. • Developed simulation to solve conversion and reaction temperature at different conditions. • Performed force analysis on a single particle with different reactor orientations. [ABSTRACT FROM AUTHOR]

Phosphoric acid used as a proton-conductive medium in high-temperature polymer electrolyte membrane fuel cells (HT-PEMFCs) poisons the Pt surface and prevents oxygen transport in the cathode catalyst layer. The hydrophobic binders in the catalyst not only maintain the catalyst layer structure but also control the phosphoric acid distribution. In this study, polytetrafluoroethylene (PTFE)/carbon black (Vulcan XC-72R) added to the catalyst layer generates an oxygen transport channel. The catalyst layers coated on the gas diffusion layer by the bar-coating method serve as the cathode. High PTFE content causes hydrophobicity in the catalyst layer. The membrane electrode assembly (MEA) with 6 wt% PTFE/Vulcan results in the highest peak power density (0.347 W cm−2) and voltage (0.653 V) at 0.2 A cm−2. A critical reason for its high performance is having the lowest R ct + R mt values measured at 0.6 V and 0.4 V. These results could contribute to improving the MEA performance for HT-PEMFCs. • High PTFE content causes hydrophobicity in the catalyst layer. • PTFE in the catalyst improved membrane electrode assembly performance. • PTFE/Vulcan successfully allowed oxygen transport. • Too high PTFE content decreased proton conductivity [ABSTRACT FROM AUTHOR]

The use of hydrogen as a fuel is increasing exponentially, and the most economical way to store and transport hydrogen for fuel use is as a high-pressure gas. Polymers are widely used for hydrogen distribution and storage systems because they are chemically inert towards hydrogen. However, when exposed to high-pressure hydrogen, some hydrogen diffuses through polymers and occupies the preexisting cavities inside the material. Upon depressurization, the hydrogen trapped inside polymer cavities can cause blistering or cracking by expanding these cavities. A continuum mechanics–based deformation model was deployed to predict the stress distribution and damage propagation while the polymer undergoes depressurization after high-pressure hydrogen exposure. The effects of cavity size, cavity location, and pressure inside the cavity on damage initiation and evolution inside the polymer were studied. The stress and damage evolution in the presence of multiple cavities was also studied, because interaction among cavities alters the damage and stress field. It was found that all these factors significantly change the stress state in the polymer, resulting in different paths for damage propagation. The effect of adding carbon black filler particles and plasticizer on the damage was also studied. It was found that damage tolerance of the polymer increases drastically with the addition of carbon black fillers, but decreases with the addition of the plasticizer. • A hyper-elastic damage model was deployed to simulate rapid decompression failure. • Study performed on three variants of EPDM polymer; pure, filled, and plasticized. • Addition of carbon black fillers suppresses the damage initiation and evolution. • Addition of plasticizer increases the chances of damage during rapid decompression. [ABSTRACT FROM AUTHOR]

One of the limitations of conventional carbon-supported Pt electrocatalyst in Proton Exchange Membrane Fuel cell (PEMFC) is the carbon corrosion during start-up and shut-down of a fuel cell. The present work investigates the stability of three different carbon blacks and their functionalized forms as supports for Pt electrocatalysts. Acetylene black (AB) as a low surface area carbon shows a higher degree of graphitization and effective functionalization than Vulcan carbon and Ketjan black. Electrochemical tests on corrosion studies show that the AB and its functionalized form (f- AB) as support for Pt electrocatalyst exhibits good electrochemical activity with an ECSA of 52 m2g-1 and 78 m2g-1 and excellent corrosion resistance with minimum ECSA loss of 6% and 16% for Pt/AB and Pt/ f- AB, respectively, satisfying the DoE target (<40% ECSA loss.) This makes the Pt/ f- AB a promising durable electrocatalyst for PEMFC with improved activity and durability. [Display omitted] • Acetylene black possesses higher graphitic content. • Effect of acid functionalization on different carbonaceous materials. • Electrochemical impedance spectroscopy as tool for carbon corrosion evaluation. • Functionalized acetylene black acts as highly durable support for PEMFC cathodes. • The Pt electrocatalyst exhibits performance better than DOE targets. [ABSTRACT FROM AUTHOR]

The microporous layer (MPL) of diffusion medium has an important impact on the water management ability of proton exchange membrane fuel cells. In this study, six kinds of carbon black were used to prepare the cathode MPL. The thickness, conductivity, pore structure, hydrophobicity, and surface microstructure of MPL were characterized. The single cell was prepared and electrochemical tests were performed. The results showed that the single cell prepared by Acetylene black (ACET) and Vulcan XC-72R has a considerable power generation performance. In addition, polyvinylidene fluoride hexafluoropropylene copolymer P(VDF-HFP) was used to replace Polytetrafluoroethylene (PTFE) as hydrophobic binder. MPL with different P(VDF-HFP) contents were prepared, and the single cell performance was investigated. The results showed that all the single cells prepared by P(VDF-HFP) were worse than that of PTFE. This study provides an important reference for further improving the performance of fuel cells from the perspective of material optimization with MPL. • Six kinds of carbon black were used to prepare the cathode MPL. • Single cell prepared by ACET and Vulcan XC-72R has a considerable performance. • MPL with different P(VDF-HFP) contents was prepared. • All the single cell performance prepared by P(VDF-HFP) were worse than that by PTFE. [ABSTRACT FROM AUTHOR]

Developing effective earth aboundant non-precious metal electrocatalysts for oxygen reduction reaction (ORR) is highly demanded in clean energy conversion systems, such as fuel cells. In this work, we demonstrate N,F dual-doped carbon embedded with Co&CoN paragenetic structure (N,F–Co&CoN@C) as an effective ORR electrocatalyst through directly pyrolyzing the solid mixture of cobalt chloride hexahydrate, melamine hydrogen fluoride and carbon black in an N 2 atmosphere. N,F–Co&CoN@C prepared at 700 °C (N,F–Co&CoN@C700) exhibits an excellent electrocatalytic performance with the ORR peak potential (E p) at 0.875 V, the half wave potential (E 1/2) at 0.871 V and a nearly four-electron reaction path in 0.1 M KOH. It also displays a better stability and methanol-tolerance than that of the commercial 40 wt% Pt/C. Origin of this outstanding performance of the prepared N,F–Co&CoN@C700 comes from the synergistic effect of Co&CoN and N,F–C in the hybrid materials. TEM images, STEM-mapping images, XRD and XPS results verify that N,F–Co&CoN@C700 has a core@shell structure with Co&CoN paragenetic structure embedded in N, F dual-doped carbon. Its specific surface area is calculated to be 1018 m2/g with a high defect degree of the I D /I G at 1.31. Image 1 • N,F-doped carbon with Co&CoN paragenetic structure (N,F–Co&CoN@C) is prepared. • N,F–Co&CoN@C700 shows an E p at 0.875 V, E 1/2 at 0.871 V and a four-electron path. • N,F–Co&CoN@C700 has a better durability and methanol-tolerance than 40 wt% Pt/C. • N,F–Co&CoN@C700 owns the synergistic effect of Co&CoN and N,F–C in the hybrid. • Its specific surface area is 1018 m2/g with the I D /I G at 1.31. [ABSTRACT FROM AUTHOR]

Although direct formic acid fuel cell (DFAFC) is regarded as one of the most promising energy-conversion systems, its commercialization process is impeded by the high costs of electrode catalysts as well as the sluggish catalytic reaction kinetics. Herein, we present a convenient bottom-up method to the synthesis of nanosized Pd crystals grown on 3D porous hybrid nanoarchitectures constructed from MXene (Ti 3 C 2 T x) and reduced graphene oxide nanosheets (Pd/MX-rGO) through a co-assembly process. The as-derived 3D Pd/MX-rGO nanoarchitecture is equipped with a number of attractive textural features, such as 3D cross-linked porous networks, large specific surface area, uniform Pd dispersion, optimized electronic structure, and good electron conductivity. As a result, unusual formic acid oxidation properties in terms of high catalytic activity, strong poison tolerance, and reliable long-term stability are achieved for the 3D Pd/MX-rGO catalyst, significantly superior to those for conventional Pd catalysts supported by carbon black, graphene, and Ti 3 C 2 T x matrixes. The controllable growth of Pd nanocrystals on MXene and reduced graphene oxide co-constructed 3D nanoarchitectures is achieved by a bottom-up co-assembly method. By virtue of the porous networks and optimized electronic structure, the resulting 3D catalyst exhibits superior electrocatalytic properties toward formic acid oxidation reaction. Image 1 • The bottom-up construction of 3D Pd-decorated MXene/rGO architecture is achieved. • The 3D porous frameworks facilitate the transportation of both electrons and ions. • The incorporation of MXene can effectively optimize the electronic structure of Pd. • The resulting 3D architecture exhibits high activity for formic acid oxidation. [ABSTRACT FROM AUTHOR]

A platinum electrocatalyst was presented for oxygen reduction reaction that the durability to potential cycling was enhanced. It was synthesized by coating carbon black with a silica layer, followed by Pt deposition on it. To investigate the durability of the electrocatalyst, two accelerated degradation testing protocols were carried out. Carbon corrosion and platinum metal degradation properties were evaluated under the potential cycling between 1.0 and 1.5 V and between 0.6 and 0.95 V, respectively. Silica-coated catalysts (Pt/CB-SiO 2) showed better stabilities compared to the commercial Pt/C catalyst under both of the two protocols. Commercial Pt/C catalyst initially had better mass activity than silica-coated catalysts but it became similar after the potential cycling of carbon corrosion. TEM showed the platinum particle aggregation and particle density decrease especially for the commercial catalyst by the potential cycling. The silica coating prevents carbon corrosion by blocking the carbon support from direct contact with the oxygen source and preventing the effect of oxygen spillover from the platinum to carbon during the potential cycling between 1.0 and 1.5 V. It also alleviates platinum dissolution in reverse scans by reducing the formation of Pt oxide during potential cycling in between 0.6 and 0.95 V. The results suggest the coating of carbon support can enhance the durability of Pt/C catalyst to the potential cycling. • Carbon black was successfully coated with silica. • Platinum was deposited preferentially on the silica over the carbon black surface. • The silica coating improved the durability of Pt/C under two types of ADT. • Silica coating counteracted the effect of the oxygen spillover from Pt to carbon. • Silica coating shifted Pt oxidation potential to the higher value. [ABSTRACT FROM AUTHOR]

The present work focuses on the optimization of operating parameters using Box Behnken design (BBD) in RSM to obtain maximum power density from a glycerol based air-breathing T-shaped MFC. The major parameters influencing the experiment for enhancing the cell performance in MFC are glycerol/fuel concentration, anode electrolyte/KOH concentration, anode electrocatalyst loading and cathode electrolyte/KOH concentration. The ambient oxygen is used as the oxidant. The acetylene black carbon (C AB) supported laboratory synthesized electrocatalyst Pd–Pt (16:4)/C AB is used as anode electrocatalyst and commercial Pt (40 wt%)/C HSA as the cathode electrocatalyst. The quadratic model predicts the appropriate operating conditions to achieve highest power density from the laboratory designed T-shaped MFC. The p-value of less than 0.0001 and F-value of greater than 1 i.e., 26.32 indicate that the model is significant. The optimum conditions predicted by the RSM model were glycerol concentration of 1.07 M, anode electrolyte concentration of 1.62 M anode electrocatalyst loading of 1.12 mg/cm2 and cathode electrolyte concentration of 0.69 M. The negligible deviation of only 1.07% between actual/experimental power density (2.76 mW/cm2) and predicted power density (2.79 mW/cm2) was recorded. This model reasonably predicts the optimum conditions using Pd–Pt (16:4)/C AB electrocatalyst to obtain maximum power density from glycerol based MFC. Image 1 • Synthesized Pd–Pt (16:4)/C AB anode electrocatalyst is used for glycerol electrooxidation. • Air breathing F-shaped microfluidic fuel device used for single cell study. • Operating parameters for air breathing T-shaped MFC were optimized by RSM. • Maximum power density predicted by model (2.79 mW/cm2) is very close to experimental. [ABSTRACT FROM AUTHOR]

The performance of microbial fuel cells (MFCs) consisting of exfoliated porous graphitic carbon nitride (ep-GCN) and its composite with acetylene black (AB) as cathode catalyst is evaluated. The cyclic voltammetry and electrochemical impedance spectroscopy of composite ep-GCN-AB indicated excellent oxygen reduction reaction activity and comparable charge transfer resistance with respect to Pt–C. The absence of X-ray diffraction peak at 2θ = 13° (corresponding to stacked structure of bulk GCN) indicated reduction in thickness. Four MFCs were operated with simulated wastewater with chemical oxygen demand (COD) of 3000 mg L−1. The maximum power densities of MFC-GAB (14.74 ± 0.17 W m−3), MFC-PAB (15.68 ± 0.58 W m−3) and MFC-G (12.47 ± 0.30 W m−3) using ep-GCN-AB, Pt–C and ep-GCN electrocatalyst, respectively, were 2.6, 2.7 and 2.2 times higher than MFC-AB operated with only acetylene black coated cathode. The investigation demonstrates that ep-GCN and its composites can be utilized as excellent cathode catalysts in MFCs at 20 folds lesser cost than Pt–C. Image 1 • Synthesis of exfoliated porous graphitic carbon nitride (ep-GCN) cathode catalyst. • Addition of acetylene black (AB) to enhance the electrocatalytic activity of ep-GCN. • Comparable power performance of MFCs utilizing ep-GCN-AB and Pt–C. • Power recovered per unit cost of catalyst 20 times more for MFC with ep-GCN-AB. • Excellent low-cost alternative to Pt–C cathode catalyst in MFC. [ABSTRACT FROM AUTHOR]

The two-step decoration of the Ag nanoparticles supported on carbon black (Ag/C) with Au and Pt, the electrooxidation of glycerol on the Pt/Au/Ag/C catalysts in alkaline solution, and the effect of the amounts of Au and Pt on the catalytic activity of Pt/Au/Ag/C are investigated. The decoration of Ag/C is performed by electrochemically depositing a small amount of Au and then Pt on Ag/C, and the Pt x /Au y /Ag 100 /C catalysts with different x : y :100 ratios (0.15 ≤ x ≤ 1.9 and 0.2 ≤ y ≤ 1.5) are obtained. Physical and electrochemical characterizations reveal that small parts of the Ag surfaces are covered by the deposited Au and Pt. Pt x /Au y /Ag 100 /C mainly shows Pt-relevant behaviors in glycerol oxidation, and Pt 1.3 /Au y /Ag 100 /C exhibits high catalytic activities. The results reveal that the surface decoration is a useful method of fabricating efficient ternary catalysts at low cost. • Pt/Au/Ag/C is prepared by decorating Ag/C with small amounts of Au and Pt. • Activity of Pt/Au/Ag/C depends on the decoration sequence and masses of Au and Pt. • Pt 1.3 /Au y /Ag 100 /C (y ≤ 1.5) shows high catalytic activity for glycerol oxidation. [ABSTRACT FROM AUTHOR]

We design and construct a novel heterostructured CoSe 2 /Ni 3 Se 4 @N-doped carbon nanosheets/Ketjen black carbon (denoted as CoSe 2 /Ni 3 Se 4 @NC/KB) via the combination of pyrolysis and hydrothermal method. As a result of the exceptional synergism between CoSe 2 and Ni 3 Se 4 as well as high conductivity of carbon materials, the obtained CoSe 2 /Ni 3 Se 4 @NC/KB drives an OER current density of 10 mA cm−2 by an overpotential of 260 mV and displays a low Tafel slope of 68 mV dec−1, outmanoeuvring commercial RuO 2 and IrO 2 , control groups (i.e. Ni 3 Se 4 @NC/KB, CoSe 2 @NC/KB, and CoSe 2 /Ni 3 Se 4 @NC), as well as most hybrids of selenides and carbon materials reported recently. • We design a novel heterostructured CoSe 2 /Ni 3 Se 4 @NC/KB hybrid. • This hybrid is constructed via the combination of pyrolysis and hydrothermal method. • This hybrid affords excellent OER activity, superior to commercial RuO 2 and IrO 2. • The marked comprehensive properties of this hybrid are due to its rational structure. [ABSTRACT FROM AUTHOR]

Surface wettability of gas diffusion media (GDM) is one of the key issues related to the water management in fuel cells. In this study, a facile coating approach of combining carbon black and polydimethylsiloxane (PDMS) is developed to fabricate the gas diffusion layer (GDL) with super hydrophobic and hierarchical surfaces. Due to the Wenzel and Cassie's effect, the fabricated GDL shows the average contact angle as high as 158° and the roll angle less than 5°. Its super durability could be identified by the constant potential oxidation with the oxidization peak current approaching to 0.1 mA cm−2, an order of magnitude smaller than that of conventional GDL coated with polytetrafluoroethylene (PTFE) and carbon black (10/90 wt/wt). Furthermore, these hierarchical hydrophobic surfaces exhibit a recovery of hydrophobicity from 107° to 133° by heat treatment. The mechanism of the exceptional self-healing capability is investigated by microscopic and spectroscopic analysis. It is indicated that ring siloxanes with lower surface tension formed on GDL surface during heat treatment process. This paper provides a fundamental research on the hierarchical superhydrophobic surfaces of GDL and a promising solution to develop long-live super hydrophobic GDL. • Polydimethylsiloxane and carbon black combined together to prepare the GDL. • The micro-nanometer composite structure appeared on the GDL surface. • The results of constant potential oxidation showed better durability. • The oxidized GDL regained the hydrophobicity from 107° to 133° with the heat treatment. [ABSTRACT FROM AUTHOR]

The adoption of new environmentally responsible technologies, as well as, energy efficiency improvements in equipment and processes help to reduce CO2 rate emission into the atmosphere, contributing in delaying the consequences of intensive use of fossil fuels. For more effective actions, it is necessary to make the transition from the fossil-based to the renewable source economy. In this context, hydrogen fuel has a special role as clean vector of energy. Hydrogen has the potential to be decisive in mitigating greenhouse gas emissions, but fossil fuels high profitability due to global energy dependency actually drives the global economy. While renewable energy sources are not worldwide fully established, new technologies should be developed and used for the recovery of energetic streams nowadays wasted, to decarbonize hydrocarbons and to improve systems efficiency creating a path that can help nations and industries in the needed energy economy transition. Hydrogen gas can be generated by various methods from different sources such as coal and water. Currently, almost all of the hydrogen production is for industrial purpose and comes from the Steam Reforming, while the use of hydrogen in fuel cells is only incipient. The article analysis the plasma pyrolysis of hydrocarbons as a decarbonization option to contribute as a step towards hydrogen economy. It presents the Carbon Black and Hydrogen Process (CB&H Process) as an alternative option for hydrogen generation at large scale facility, suitable for supplying large amounts of high-purity carbon in elemental form. CB&H Process refers to a plant with hydrogen thermal plasma reactor able to decompose Hydrocarbons (HC's) into Hydrogen (H2) and Carbon Black (CB), a cleaner technology than its competing processes, capable of generating two products with high added value. Considering the Brazilian context in which more than 80% of the generated electricity comes from renewable sources, the use of electricity as one of the inputs in the process does not compromise the objective of reducing greenhouse gas emissions. It is important to consider that the use of renewable energy to produce two products derived from fossil fuels in a clean way represents integration of technologies into a more efficient system and an arrangement that contributes to the transition from fossil fuels to renewables. The economic viability of the CB&H process as a hydrogen generation unit (centralized) for refining applications also depends on the cost of hydrogen production by competing processes. Steam Methane Reforming (SMR) is a widespread method that produces twice the amount of hydrogen generated by natural gas plasma pyrolysis, but it emits CO2 gas and consumes water, while CB&H process produces solid carbon. For this reason, the paper seeks the carbon production cost by plasma pyrolysis as a breakeven point for large-scale hydrogen generation without water consumption and carbon dioxide emissions. • Decarbonization option technology to contribute as a step towards of hydrogen economy. • Cleaning fossil fuels by electricity and hydrogen. • Value of carbon as a decisive parameter in mitigating greenhouse gases. • Carbon cost as a breakeven point for hydrogen at large scale without carbon dioxide. • Transition from the fossil-based to the renewable source economy. [ABSTRACT FROM AUTHOR]

Pt is the most commonly used electrode and catalyst materials for H 2 production via water splitting as it provides the highest Gibbs free energy of H 2 adsorption (ΔG H) an d overpotential. However, as Pt catalysts are expensive and difficult to mass-produce, several efforts have been made to identify suitable substitutes. Although Cu provides lower ΔG H and overpotential than Pt, it exhibits better catalytic performance than other catalysts and is suitable for H 2 production. However, corrosion of Cu may affect its stability of Cu electrode. To overcome this limitation, we have coated a layer of carbon on the copper electrode and then synthesized titanium dioxide-(TiO 2 -) on the C/Cu electrode for water splitting application. Carbon black (CB) has excellent electrical conductivity and stable resistance for effective working as an electrochemical catalyst, and TiO 2 has diverse applications because of its low-cost, non-toxic, and corrosion-resistant characteristics. In this study, TiO 2 was synthesized on C/Cu electrodes under UV irradiation for different durations. The optimum irradiation duration was determined to be 15 min via surface and electrochemical analyses. To identify the potential applications of this TiO 2 –C/Cu electrode, we used artificial wastewater as the electrolyte. The synthesized TiO 2 –C/Cu electrode exhibited better stability than C/Cu electrode. Further, H 2 production with TiO 2 –C/Cu electrode was higher than that with C/Cu electrode at the same current density. We also investigated the effect of TiO 2 –C/Cu electrode on decomposition of formaldehyde. • Development of TiO 2 –C/Cu electrode for hydrogen production by UV irradiation. • Cu corrosion was prohibited due to TiO 2 layer. • Enhancement of hydrogen production by TiO 2 –C/Cu electrode. • Decomposition of formaldehyde in artificial wastewater by TiO 2 –C/Cu electrode. [ABSTRACT FROM AUTHOR]

To alleviate the sluggish oxygen evolution reaction (OER) kinetics, it's urgent to develop electrocatalysts with high activity and low cost. In this work, Fe doped metal organic frameworks (Ni)/carbon black composites were synthesized via a facile hydrothermal method. Benefiting from the direct use of metal organic frameworks (MOFs) for OER, numerous and highly dispersed active sites are exposed to the electrolyte and reactants. By regulating Ni/Fe ratios, a high electrochemical active surface area (ECSA) and high relative surface content of active Ni3+ species are obtained, which mainly contribute to the high OER activity. Besides, the introduced carbon black (CB) was found to enhance the charge-transfer efficiency of the electrocatalysts, which is also favorable for OER. The optimal Ni9Fe1-BDC-0.15CB electrocatalyst shows excellent OER activity with the low overpotential of ~290 mV at 10 mA cm−2 and the Tafel slope of ~76.1 mV dec−1, which is comparable to RuO 2 and other MOFs-based OER electrocatalysts reported in recent years. Image 1 • Bimetal NiFe MOFs/CB composite was directly used as OER electrocatalyst. • NiFe-BDC-CB shows a structure of nanosheets decorated with CB nanospheres. • A moderate Ni/Fe ratio can improve relative contents of Ni3+ active sites for OER. • NiFe-BDC-CB shows high OER electrocatalytic activity and durability. [ABSTRACT FROM AUTHOR]

This study examined the possibility of hydrogen production using a solution plasma process (SPP). The reactants were lignin model compounds and actual lignin oil. The highest amount of hydrogen was generated in SPP using m-cresol. The total amount of gas generated by the plasma reaction for 20 min using 23 g of m-cresol was 1.69 L, which comprised of 65.51% hydrogen and 29.85% CO. Furthermore, a maximum of 1.91 L of hydrogen was generated by a reaction between pyrolysis oil and ethanol with a weight ratio of 1:1. The presence of carbon black, a reaction byproduct, was measured by Fourier transform infrared spectroscopy, which revealed molybdenum trioxide peaks. It was confirmed that molybdenum used as an electrode was doped on carbon. • Hydrogen was produced from bio-oil using solution plasma process. • Guaiacol, m-cresol, and anisole were used as model bio-oil compounds. • Among model bio-oils, m-cresol achieved the highest hydrogen yield. • Lignin bio-oil with ethanol produced 1.91L hydrogen from solution plasma process. • Carbon black doped with electrode material was formed as byproduct. [ABSTRACT FROM AUTHOR]

Carbon materials have previously been reported to work as catalysts for hydrogen (H 2) production from hydrocarbons. Mechanisms of the catalytic behavior of graphite and carbon black (CB) have often been discussed in literature. Graphite and CB is constructed from mainly 6-membered rings with sp 2 bonds. To understand the catalytic behavior of carbon materials for H 2 production by methane (CH 4) decomposition, the catalytic behavior of fullerenes with 6-membered rings and also those comprising 5- and 7-membered rings with sp 2 bonds and their associated mechanisms should be investigated. In this study, the fullerene catalyst activity has been investigated using gas chromatography and the electronic states and nanoscale structures have been analyzed. H 2 production started at 400 °C and the H 2 production rate gradually increased with time, and the activation energy of the fullerene for H 2 production by CH 4 decomposition was found to be 166 kJ/mol. Moreover, in situ heating X-ray photon spectroscopy (XPS) measurements showed that the π-π∗ transition signal becomes stronger with increasing temperature above the threshold of 300 °C. The transition of the π electrons to π∗ orbitals upon heating is expected to decompose CH 4 absorbed on fullerene. Moreover, transmission electron microscopy (TEM) analysis revealed that the generated carbon atoms from the CH 4 decomposition were deposited onto the surfaces of the fullerenes, forming amorphous and layered concentric sphere carbon. Amorphous carbon is reported to not work as a catalyst for CH 4 decomposition at around 400 °C. From XPS analysis and TEM observations of these two structures, it is anticipated that the ring structures without 6-membered rings in carbon materials with sp 2 bonding contribute to this catalytic behavior for CH 4 decomposition at a low temperature of 400 °C. • Fullerenes have catalytic ability for H 2 production from CH 4 starting from 400 °C. • In situ heating XPS analysis showed that π electrons were exited from 400 °C. • Amorphous and concentric sphere carbon appeared only after reaction with fullerene. • H 2 production rate gradually became higher with time. • Ring structures without 6-membered rings of carbon can have catalytic abilities. [ABSTRACT FROM AUTHOR]

Chemical-looping methane decomposition using activated carbon as a catalyst has been considered a potentially promising approach for high-purity H 2 production with low cost and low CO 2 emission. However, activated carbon is known to deactivate fast despite its high initial catalytic activity. Oppositely, carbon black has shown stable catalytic methane decomposition that even increases slowly with time of reaction. Considering these two different activity trends, activated carbon and carbon black are jointly used to prepare catalysts and then test for the decomposition of the methane via chemical looping in this study that aimed to examine catalyst and reaction properties which may combine the high initial activity of activated carbon with the steady-and-increasing activity of carbon black. These mixed catalysts are examined using X-ray diffraction analysis (XRD), scanning electron microscopy and energy dispersive spectroscopy (SEM/EDS), Brunauer-Emmett-Teller (BET) and high-resolution transmission electron microscopy (HRTEM) before and after reaction testing to reveal chemical and physical constituents which contributed to their reactivities, and the mechanism of long catalytic activity has been discussed. The results point to insights and potential directions for modifying carbonaceous catalysts for chemical looping thermo-catalytic decomposition of methane. • Advantages of AC and CB were combined and joint-use of them were proposed. • AC/CB mixtures shows good initial and favorable long-lasting activity. • Graphene layers of deposited carbon grow with different angles. • Structural defects of graphene layers provide new active sites during reaction. [ABSTRACT FROM AUTHOR]