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Dissolved black carbon (DBC) can generate reactive oxygen species (ROS), playing significant roles in contaminants degradation and chemical stresses to microorganisms. However, little is known regarding the photoproduction sites to ROS generation, mainly because of its extremely complicated composition. Herein, the ROS generation and photoexcited alteration of DBC were investigated. The generation mechanisms of hydroxyl radical (•OH), superoxide anion (O 2 •−), and singlet oxygen (1O 2) were inferred by employing various model chemicals. Results showed that the photo-excited aliphatic carbonyls greatly contributed to ∙OH, O 2 •−, and 1O 2 generation. Ether groups were identified as the main structural source of H 2 O 2 -dependent ∙OH generation. The novel non-electron transfer process involved carbonyl, ether, alcohol, and ester groups to produce O 2 •− was proposed. These findings reveal the vital role of oxygenated functional groups within DBC in the photoactive generation of ROS, and thus provides new theoretical information for DBC's environmental geochemical behavior. [Display omitted] • Carbonyls within DBC substantially participated the generation of ROS. • Ether components were the structural source of H 2 O 2 -dependent ∙OH generation. • The 1O 2 production was determined by both unsaturation and molecular weight of DBC. • Oxygenated functional groups could generate O 2 •− by non-electron transfer process. [ABSTRACT FROM AUTHOR]

Simple, large-scale synthesis of metal single-atom catalysts (SACs) is limited by the aggregation of metal atoms on the support material surface. The N atoms in small organic ligands (SOLs) can anchor single metal atoms, affording abundant surface-active sites. In this study, we investigated the effect of the nitrogen/carbon ratio (N/C) in SOLs on the properties of the resultant Ni single-atom confined nitrogen-doped carbon black (Ni-NCB). The N/C ratio affected the thermal stability of Ni-NCB_N/Cs during carbonization, and the optimal Ni-NCB (Ni-NCB_0.5) was synthesized with the SOL 2-methylimidazole. Ni-NCB_0.5 achieved a CO partial current density of > 500 mA cm–2 and high CO Faradaic efficiency (96.4 %) in the CO 2 reduction reaction. The 3- and 4-cell stack systems with Ni-NCB_0.5 (25 cm2 area per unit cell) exhibited an overall current of 10 A, high CO selectivity (> 96.0 %), and long-term stability (50 h). This synthetic strategy for SACs can be commercialized and even extended to other industrial electrocatalysts. [Display omitted] • N/C of organic ligands is one of key factors to control amount of N detect in support • A significant correlation existed between the N and Ni content in SACs • Optimal Ni-NCB (N/C = 0.5) possessed abundant atomic active sites. • Cell stacks with Ni-SAC_0.5 showed 40 A CO production and 50 h stability in CO 2 RR. [ABSTRACT FROM AUTHOR]

Benefiting from the optimized free energy of hydrogen adsorption (ΔG *H) and the enhanced electrical conductivity derived from nitrogen doping, the obtained N-CoP/CC nanoflower exhibits remarkable HER performance, with overpotentials of 74 mV, 39 mV and 25 mV to achieve the current density of 10 mA cm−2 in 1.0 M PBS, 1.0 M KOH and 0.5 M H 2 SO 4 , respectively. • N-CoP/CC exhibits outstanding HER performance with an overpotential of 74 mV at 10 mA cm−2 in 1.0 M PBS, outperfroming most of the reported TMPs. • N-CoP/CC exhibits excellent HER performance in a wide pH range from 0 to 14. • DFT calculations reveal that doping with N can optimize the ∆G *H of CoP to the optimal value, resulting in enhanced HER performance. Although significant achievements have been made in the development of efficient transition metal phosphide (TMP) based electrocatalysts for hydrogen evolution reaction (HER) under acidic and alkaline media, TMP-based electrocatalysts with remarkable HER performances under neutral media has been rarely reported. Herein, we report the synthesis of nitrogen doped CoP nanoflower grown on conductive carbon cloth (N-CoP/CC) that possesses excellent HER performance, with an overpotential of 74 mV to achieve the current density of 10 mA cm−2 in 1.0 M PBS (phosphate buffer solution, pH = 7), outperforming almost all the documented non-noble TMP-based electrocatalysts. In addition, the N-CoP/CC also displays Pt-like performance in 1.0 M KOH and 0.5 M H 2 SO 4 , with overpotentials of 39 and 25 mV to achieve the current density of 10 mA cm−2, respectively. Density functional theory (DFT) calculations and experimental results reveal that doping with N can efficiently affect the electronic states of Co d -orbital and optimize the free energy of hydrogen adsorption (ΔG *H) to the optimal value, resulting in enhanced HER performance. [ABSTRACT FROM AUTHOR]

• Bi-modified Pt catalyst is applied to a direct formic acid fuel cell (DFAFC) anode. • Bi was irreversibly adsorbed on Pt catalyst by a simple synthetic strategy. • Bi-modified Pt/C showed significantly high formic acid oxidation reaction activity. • A DFAFC stack fabricated using Bi-modified Pt/C yielded a power of 300 W. • The simple synthetic strategy can be applied to achieving DFAFC stacks commercially. Formic acid is a chemical with a simple molecular structure containing hydrogen. This liquid at room temperature is easy to handle and has a low toxicity, and is thus in the spotlight as a fuel. In particular, formic acid is an excellent fuel candidate because it can be operated at low temperatures when applied as a fuel in fuel cells with a high theoretical open-circuit voltage (1.48 V). However, it has a drawback in that the electrode catalyst is deactivated due to the generation of CO intermediates when formic acid is oxidized during cell operation. Therefore, to prevent this, an irreversibly adsorbed Bi on Pt catalyst is applied to a direct formic acid fuel cell (DFAFC) anode because it is easy to synthesize and economical. Physical analyses such as transmission electron microscopy (TEM), X-ray diffraction (XRD), and thermogravimetric analysis (TGA) were conducted, and electrochemical evaluations were performed through half-cell and single-cell level tests. The results revealed that the formic acid oxidation reaction activity of the Bi-modified Pt/C was 13 times higher than that of the conventional catalyst at 0.58 V. Further, a DFAFC stack was fabricated using the Bi-modified Pt/C, which yielded a power of 300 W. These results suggest that a simple synthesis method can be applied to fabricating industrially available DFAFC stacks. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • 2,4-DCBA was efficiently removed by moveable carbon-supported Pd catalysts. • The catalysts morphologies and chemical structures maintained during the reaction. • Pd/CB exhibited the highest adsorption and dechlorination ability. • The issues of easy loss of Pd and poor long-term performance were addressed. Abstract In the present study, carbon black (CB), multi walled carbon nanotubes (MWCNTs), and granular activated carbon (GAC) were employed to support palladium (Pd) catalyst. The prepared Pd/CB, Pd/MWCNTs and Pd/GAC moveable catalysts were aimed to address the common issues (easy loss of catalyst and poor long-term performance) of normal fixed catalysts. The results of various characterizations (e.g., TEM, XRD, and XPS) clearly show that the Pd nanoparticles were successfully loaded onto the carbon-supports, especially CB and MWCNTs. And more importantly, the morphologies, Pd distribution, and chemical structure of these moveable catalysts were almost not changed after 3 h reaction. The moveable Pd/CB, Pd/MWCNTs, and Pd/GAC catalysts had good reactivity for 2,4-dichlorobenzoic acid (2,4-DCBA) dechlorination, and Pd/CB exhibited the best performance. The Pd/CB also shows the best adsorption capacity of 2,4-DCBA and dechlorination product (benzoic acid, BA), and the adsorption of BA was significantly inhibited in the presence of current due to the repulsion between the both negatively charged compounds and adsorbents. The removal of 2,4-DCBA and the generation rate of BA was improved with a pre-adsorption process, which was a promising strategy with higher dechlorination rate and shortened electrolysis time. Moreover, the loss of Pd catalyst was negligible during the 10 consecutive cycles experiment, and the improved longevity could be expected. These results suggested the good reactivity, stability, and reusability of moveable Pd/CB catalyst. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • ORR activity of La 0.8 Sr 0.2 Co x Fe 1-x O 3-δ /C electrocatalysts in 0.1 M KOH was assessed. • ORR activity increased gradually with increasing substitution of Fe by Co. • Electron transfer number increased with increasing substitution of Fe by Co. Abstract A series of La 0.8 Sr 0.2 Co x Fe 1-x O 3-δ (LSCF) perovskite oxides, including La 0.8 Sr 0.2 CoO 3-δ (LSC) and La 0.8 Sr 0.2 FeO 3-δ (LSF), were synthesized via a combustion method and, mixed with carbon black at a mass ratio 3:1, were studied towards their oxygen reduction reaction (ORR) activity in 0.1 M KOH solution at room temperature, using the thin-film rotating disk electrode (RDE) technique. The highest and lowest ORR (specific and mass) activities among the tested electrocatalysts were exhibited by LSC and LSF, respectively. Increasing Co content and at the same time decreasing Fe content in the LSCF composition, resulted in ORR specific activity enhancement as well as in an increase in the number of transferred electrons, from ca. 2 (for LSF) to ca. 4 (for LSC), implying a change in the ORR mechanism. The observed change in ORR activity of the perovskite/C electrocatalysts upon gradual substitution of iron by cobalt was associated with induced changes in the surface B-sites electronic structure and in surface oxygen vacancy formation. [ABSTRACT FROM AUTHOR]

Graphical abstract Highlights • Pd nanoparticles supported on carbon black were encapsulated by mesoporous silica. • The 3D nature of interconnecting pores was confirmed by electron tomography. • The covered catalyst resists sintering but the underlying active phase is accessible. • The catalyst is performant in glucose oxidation due to improved hydrophilicity. Abstract Palladium nanoparticles supported on carbon black were encapsulated in a thin mesoporous silica layer. APTES ((3-aminopropyl) trimethoxysilane) was used as anchoring agent to ensure robust and homogeneous formation of a mesoporous SiO 2 layer around the supported catalyst. This was confirmed by XPS, TEM, electron tomography and nitrogen physisorption measurements. The covered catalyst was tested in the oxidative dehydrogenation of glucose into gluconic acid: the high catalytic activity was maintained in comparison with uncovered catalyst, indicating that the underlying active phase was still available. In addition, the silica layer leads to high temperature stability which prevents the agglomeration of palladium nanoparticles upon sintering conditions. [ABSTRACT FROM AUTHOR]

Increasing the amount of accessible active sites to reactants is an effective way to enhance electrocatalytic activity. Although single-atom catalysts are claimed to be capable of achieving 100% atomic utilization, there may be abundant single-atom sites buried and inaccessible to reactants in practice. Herein, two Ni, N-doped carbon catalysts with Ni-N x atomic sites are comparatively studied for CO 2 electroreduction. In contrast to the Ni-N x /Carbon nanosheets with Ni loading of 2.42 wt%, the Ni-N x /Carbon black with lower Ni loading of 0.16 wt% excitingly exhibits higher activity for CO production. The atomically dispersed Ni-Nx sites over carbon black surface benefit the exposure and utilization of single-atom sites, leading to a significant increase of TOF from 2140 to 100,347 h−1 at − 0.8 V. Particularly, an extraordinarily high current density up to 300 mA cm−2 with CO selectivity of ∼100 % are achieved for Ni-N x /CB in the flow cell. This work demonstrates the significance of increasing single-atom site utilization. [Display omitted] • Ni-Nx/CNS and Ni-Nx/CB catalysts with Ni-Nx sites are synthesized for CO2RR. • Ni-Nx/CB catalyst exhibits high CO selectivity and TOF for CO2 conversion. • Ni-Nx/CB catalyst with low Ni loading exhibits high single-Ni-atoms utilization. • High current density of > 300 mA cm-2 is achieved in the flow cell. [ABSTRACT FROM AUTHOR]

The two-electrons (2e–) oxygen reduction reaction (ORR) offers a sustainable and decentralized alternative to the traditional synthetics for hydrogen peroxide (H 2 O 2) production. Although various Co single atom catalysts (SACs) have been proposed as highly effective 2e– ORR catalysts, there is still room for improvement through fine-tuned coordination environment. Here, a Co-N 5 -O-C with the combination of highly coordinated Co-N 5 moieties and nearby electro-withdrawing epoxides is first time developed to reach the optimal binding energy of *OOH intermediate, resulting in the ultrahigh mass activity of 87.5 A g−1 at 0.75 V vs. RHE. Moreover, a high H 2 O 2 production rate of 11.3 mol g−1 h−1 at 200 mA cm−2 is also obtained by a flow cell device. Such an efficient in-situ generation of H 2 O 2 further enables 100% degradation of the organic methylene blue pollutant within 15 min through the electro-Fenton process. These findings will provide a new direction for on-site H 2 O 2 synthesis and wastewater treatment. [Display omitted] • Penta nitrogen coordinated Co single-atom catalyst with rich-epoxy groups is synthesized. • DFT calculation reveals Co-N 5 with epoxy oxygen has the most favorable binding energies of *OOH for 2e- ORR. • Up to 85.6% high selectivity and ultrahigh mass activity of 87.5 A g−1 for H 2 O 2 production can be reached. • Outstanding H 2 O 2 production rate of 11.3 mol g−1 h−1 is achieved under high current density using a flow cell. • Effective organic MB pollutant degradation is demonstrated using an electro-Fenton system. [ABSTRACT FROM AUTHOR]

Supported ordered intermetallic nanoparticles are of significant interest for catalysis applications owing to their unique surface/near-surface structures and electronic properties. However, the synthesis of small-sized intermetallic catalysts with high mass activity remains a formidable challenge, as high temperatures annealing treatments are generally requisite to achieve ordered intermetallic structures but lead to undesired larger crystallites. Here, we report an industrially relevant impregnation approach for the scalable synthesis of small-sized platinum-based intermetallic nanoparticle catalysts by regulating inter-particle distance on carbon black supports to mitigate metal sintering in high-temperature annealing. We construct a library consisting of 18 binary Pt-based intermetallic nanoparticle catalysts with an average size of < 5 nm. The prepared intermetallic catalyst libraries exhibit outstanding proton-exchange-membrane fuel cells performance, including high mass activities of 1.3–1.8 A mg Pt –1, large peak power densities of 1.2–1.4 W cm–2 in H 2 -air cells, and efficient Pt utilization of ∼0.07 g kW–1 at rated power. [Display omitted] • Intermetallic compounds (IMC) have unique strain/electronic effects in catalysis. • A family of small size Pt-based IMCs was achieved by regulating inter-particle distance. • Small size and ordered IMC structure guarantee outstanding performance in fuel cell. [ABSTRACT FROM AUTHOR]

A kinetic model has been developed describing the rate of hydrogen peroxide consumption and target pollutant (phenol) degradation in CWPO with a commercial carbon black as catalyst. The model allows following the evolution of the oxidation by-products (up to 12) through a detailed reaction pathway. The kinetic parameters were obtained by fitting the experimental results in batch reactor runs at T = 90–130 °C, P = 4 bar, [Phenol] 0 = 1 g/L, [catalyst] = 0–10 g cat /L and the theoretical stoichiometric amount of hydrogen peroxide for complete mineralization of phenol (5 g/L). The results were subjected to the analysis of variance (ANOVA). The model includes a set of power-law expressions with different reaction orders which provides a complete description of the process and allows obtaining the efficiency of hydrogen peroxide consumption under giving operating conditions. [ABSTRACT FROM AUTHOR]

A facile strategy is reported for synthesizing ionic liquid supramolecules (ILSMs) as well as Pt-based alloys on the carbon black surface in a room temperature ionic liquid (1-butyl-3-methylimidazolium bis (trifluoromethylsulfonyl) imide) under one atmospheric pressure plasma. The bimetallic PtNi-nanoparticles (NPs) with a size of 2.5–3 nm are stably and uniformly hybridized on the surface of the carbon black, which is covered with a layer of ILSMs. The formation of the developed catalyst is examined using TEM, HAADF-STEM, XRD, TEM-EDS, and TGA measurements. The obtained catalyst exhibits high oxygen reduction reaction (ORR) activity, which is better than those of commercial Pt/C catalysts and Pt/C catalysts prepared without using ionic liquids. This strategy has been extended to fabricate trimetallic PtNiRu-NPs/C nanohybrids with further enhanced activities of up to 2.26 mAcm −2 and 1.31 Amg Pt −1 at 0.9 V versus RHE. The trimetallic PtNiRu-NPs/C catalyst is also more stable than the commercial product under ORR conditions due to the chemical binding of the alloys with the carbon black and the physical stabilization of the nanohybrid materials through the conductive protecting layer of the ILSMs. The results prove that the developed catalysts push the ORR toward completion and can be a promising candidate for numerous electrocatalytic applications. [ABSTRACT FROM AUTHOR]

Photocatalysis assisted oxidation of carbon black was performed using TiO 2 photocatalyst under UV illumination in an atmosphere with NO, O 2 and water vapor at 150 °C. Carbon is oxidized mainly to CO 2 while NO is selectively converted to N 2 . Enhanced O 2 and NO concentrations have a positive effect on the carbon oxidation rate. At a concentration of 3000 ppm NO and 13.3% O 2 in the gas phase the carbon oxidation rate reaches 2.3 μg carbon /mg TiO2 h, at a formal electron/photon quantum efficiency of 0.019. HR SEM images reveal uniform gradual reduction of the carbon particle size irrespective of the distance to TiO 2 photocatalyst particles in the presence of NO, O 2 and H 2 O. [ABSTRACT FROM AUTHOR]

A magnetically separable core-shell-like catalyst Ni-Pd/CB is designed and synthesized via a facile sequential reduction strategy. It is found that the Pd nanocrystals with a thickness of ∼1.67 nm and a length of ∼7.92 nm are intimately coupled with the Ni cores and the formed core-shell-like Ni-Pd nanoparticles are well dispersed on the CB surface with much smaller particle size and narrower size distribution as compared with that of unsupported ones. The ligand-free Ni-Pd/CB nanocatalyst is evaluated for Suzuki-Miyaura coupling reaction and exhibits excellent catalytic activity under mild aerobic conditions without using toxic solvents and inert protective atmosphere, achieving green catalysis. The high catalytic performance of Ni-Pd/CB catalyst can be attributed to its unique core-shell-like nanostructure and the concerted effects between the individual components. The introduction of Ni not only makes the catalyst magnetically separable in a suspension system, but also significantly lowers the cost. [ABSTRACT FROM AUTHOR]

In the present work, graphene nanoflakes (GNFs) were grown at both low and high levels of nitrogen functionalization and subsequently put through a wet-chemical method to add iron functionalities to the surface and create active catalyst centers. No mechanical treatments are used in order to minimize the formation of defects on the GNFs and evaluate if iron-nitrogen-GNF edges or surface sites can generate catalytic activity rather than the macropore structures holding these functionalities on porous carbon black. The catalysts produced under various synthesis routes were characterized and screened for their performance as an oxygen reduction reaction (ORR) catalyst. Characterization included an electrochemical study, an examination of the carbon and nitrogen content and bonding structure, in addition to Raman analysis and the calculation of the BET surface areas. It was found that samples that were both treated with iron acetate and put through pyrolysis produced the most active samples. These samples were composed of graphitic carbon and contained a large amount of pyridinic nitrogen. Additionally, when working with GNFs generated with high levels of nitrogen, no extra nitrogen source was needed during the iron incorporation step. This study further develops the GNF-based catalyst already seen to be a suitable ORR catalyst for the polymer electrolyte membrane fuel cell. [ABSTRACT FROM AUTHOR]

Carbon xerogels represent nowadays an outstanding alternative to carbon blacks for the preparation of efficient fuel cell electrocatalysts, due to their easily tunable and well developed mesoporous structure. To further improve both activity and durability of Pt/C catalysts, the introduction of heteroatoms (such as O, N, S, P, B, etc.) in the structure of carbon materials has been proposed. In the present work, highly mesoporous carbon xerogels (CXGs) have been subjected to a sulfurization process with elemental sulfur. The insertion of S into the carbon matrix does not compromise their mesoporous structure. Pt catalysts supported on sulfurized carbon xerogels show enhanced catalytic activity towards both the methanol electro-oxidation and the oxygen electro-reduction reactions, exceeding not only the performance of the catalyst supported on the bare xerogel, but also of the catalyst supported on a commercial carbon black. The sulfurization treatment is also effective in improving the resistance of Pt/CXG catalysts towards corrosion phenomena occurring at the fuel cell cathode. [ABSTRACT FROM AUTHOR]

Platinum nanoparticles supported on carbon black (CB) are used as electrocatalysts in polymer electrolyte fuel cells, and their stability is important for the durability of the catalyst system. Here, we investigated the stability of Pt nanoparticles supported on surface-treated CB with a thermochemically developed surface nanostructure. The protruding structure of surface-treated CB was able to support Pt nanoparticles synthesized via the sodium tetrahydroborate (NaBH 4 ) reduction of hexachloroplatinic(IV) acid hexahydrate (H 2 PtCl 6 ∙6H 2 O) with polyvinylpyrrolidone (PVP). The dependence of Pt stability on the deposition locations on the CB surface was examined using in situ transmission electron microscope observations during heating up to 800°C. We found that the protruding parts on the CB surface function as local sites for stably supporting Pt nanoparticles. Hence, we suggest that the stability of the Pt nanoparticles can be improved using the CB surface nanostructure. [ABSTRACT FROM AUTHOR]

A model based on a 3D representation of mixtures involving Carbon Black (CB) and commercial ceria (CeO 2 ) particles placed in a fixed bed reactor is proposed. Catalyst particles may aggregate in different ways in the whole bed and different CB–CeO 2 mass ratios are considered which range from 95–5 to 10–90. Two types of oxidation are assigned by the model: a catalytic oxidation under the influence of CeO 2 and a non-catalytic one in the other case. The activation energies of these oxidation processes have been determined through experiments, while their frequency factors are derived for the two reactions using a numerical simulation. The model simulates the CB oxidation in a good way whatever the CB–CeO 2 mass ratio, except for the 50–50 case. The catalytic oxidation is here underestimated, as the contact between CB and CeO 2 is progressively lost. [ABSTRACT FROM AUTHOR]

The photocatalytic oxidation of carbon black on TiO 2 using nitric oxide as an oxidizing agent was investigated. Layer-wise deposited carbon and TiO 2 powder was illuminated with UVA light in the presence of NO at parts per million concentrations in dry and hydrated carrier gas at a temperature of 150 °C. Carbon was photocatalytically converted mainly into CO 2 , and NO mainly into N 2 . Carbon oxidation rates of 7.2 μg/h/mgTiO 2 were achieved in the presence of 3000 ppm NO. Under these experimental conditions in the absence of molecular oxygen, formation of surface nitrates causing TiO 2 photocatalyst deactivation is suppressed. Addition of water enhances surface nitrate formation and catalyst deactivation. NO and carbon particulate matter are air pollutants emitted by diesel engines. Elimination of soot collected on a diesel particulate filter through oxidation is a demanding reaction requiring temperatures in excess of 250 °C. The present study opens perspectives for a low-temperature regeneration strategy for the diesel particulate filter that simultaneously performs DeNO x reactions. [ABSTRACT FROM AUTHOR]

Ni/C electrocatalysts were prepared by chemical deposition of nickel nanoparticles on Vulcan XC-72R carbon black using microwave irradiation technique. The time of microwave irradiation during the reduction step and nickel weight percentage were varied. This was found to affect the morphology of formed Ni/C powder as shown by TEM analysis. Increasing nickel weight percentage results in the formation of more aggregated deposits. The electrocatalytic activity of different Ni/C samples towards methanol oxidation reaction in KOH solution was studied by applying cyclic voltammetry, chronoamperometry and electrochemical impedance spectroscopic techniques. Ni/C electrocatalyst containing 30 wt.% Ni [Ni/C-30] shows 5.2 times higher electrocatalytic activity than that with 10 wt.% Ni [Ni/C-10]. Heating Ni/C powder into microwave oven using the pulse mode of 30 s on/10 s off forms the most stable electrocatalyst for prolonged oxidation reaction. Electrochemical impedance measurements show that Ni/C-30 electrocatalyst has the lowest impedance value of 0.022 kΩ cm 2 , while the highest one is for Ni/C-10 [0.331 kΩ cm 2 ] in (0.4 M methanol + 0.5 M KOH) solution at 500 mV. It confirms that Ni/C-30 has the highest electrocatalytic activity towards methanol oxidation reaction. [ABSTRACT FROM AUTHOR]

Photocatalytic water pollution remediation is currently a hot issue in the field of environmental protection. However, the limited optical adsorption, recombination of electrons and holes, as well as low kinetics in solid-liquid conditions impede the further improvement in photoactivity. Inspired by the degradation mechanism of photocatalytic process, started with interfacial engineering, in this paper, plasmonic metal-semiconductor heterostructures (PMSHs) combined with an optimized dissolved oxygen transporting channel were prepared. With the synergetic help of PMSHs and superhydrophilic-superhydrophobic (superwetting) reaction interface, it is not only can realize the effective capture of photons in the visible light band, but also promote the fully separation of electron-hole pairs. The efficiency in PMSHs based triphase system is ~60 times higher than traditional solid-liquid system, and is ~3 times higher than PMSHs based solid-liquid system. The stability and wide applicability in series organic dyes degradation also made it a good potential for practical pollutants water treatment. [Display omitted] • A hole scavenger assisted photoreduction route for the optimization of plasmonic metal-semiconductor heterostructures. • A solid-liquid-gas interface consits of a superhydrophobic carbon black and superhydrophilic plasmonic heterostructures. • ~60 and ~3 times higher SA degradation in triphase compared to P25 based diphase and plasmonic diphase, respectively. • Applicable in the series of organic pollutants and superior stability for tens of test cycles. [ABSTRACT FROM AUTHOR]

Electrochemical production of H 2 O 2 from O 2 via the two-electron reaction pathway (2e-ORR) is a promising alternative to the energy- and organic pollutant-intensive industrial anthraquinone process. However, irrespective of numerous research efforts on catalyst design and remarkable advances made in this area, the catalysts displaying high H 2 O 2 production rate so far unexceptionally required expensive/hazardous catalyst precursors and involved tedious steps and/or harsh treating conditions. Herein, we report a slightly nitrogen-doped carbon 2e-ORR catalyst that was synthesized simply by pyrolyzing a polydopamine (PDA) coating on Vulcan XC72 carbon black (p -PDA/XC). In H 2 O 2 production via ORR in an acidic electrolyte, the catalyst showed 185 mV less overpotential than XC and remarkably high selectivity up to 96%. Highly efficient and durable H 2 O 2 production was demonstrated by the stable accumulation of H 2 O 2 to 1368 mmol g cat −1 within 8 h, translating to a H 2 O 2 production rate of 171 mmol g cat −1 h−1. A good linear relationship was identified between the H 2 O 2 partial current and the surface content of the C–O/C–N and C O species for the XC and p -PDA/XC catalysts, inferring that the C atoms in or adjacent to these species serve as the active sites for 2e-ORR to H 2 O 2. The inexpensive starting materials, facile synthetic strategy, and excellent catalytic performance of the p -PDA/XC catalyst may accelerate the establishment of an affordable, safe, and direct O 2 -to-H 2 O 2 electrochemical process. [Display omitted] • N-doped carbon catalysts were fabricated by pyrolyzing polydopamine on carbon black. • The as-synthesized p -PDA/XC catalysts were effective in electrocatalyzing O 2 to H 2 O 2. • p -PDA modification markedly reduced the overpotential and enhanced H 2 O 2 selectivity. • H 2 O 2 was stably produced within 8 h at a high rate of 171 mmol g cat −1 h−1. • H 2 O 2 partial current correlated linearly with the surface content of C–O/C–N and C=O. [ABSTRACT FROM AUTHOR]

Highlights: [•] The amide-groups are grafted over carbon surface via a simple solvothermal route. [•] Cobalt oxides of 2nm uniformly supporting on the carbon blacks were synthesized. [•] CoO x /XC N shows superior ORR activity than CoO x /XC and CoO x /XC O. [•] The enhanced ORR activity is contributed to the higher content of CoO in composite. [ABSTRACT FROM AUTHOR]

Highlights: [•] Plasma treatment of carbon black and metallic precursor in a solid form is efficient to form small nanoparticles. [•] The decomposition of the metallic precursor depends on the gas nature and on the plasma power. [•] Interaction between plasma species and the carbon black support induces chemical and structural defects. [•] Chemical and structural defects act as anchoring sites for nanoparticle nucleation. [Copyright &y& Elsevier]

Highlights: [•] Graphites and carbon blacks have been tested in the CWPO of phenol (C Phenol,0 =1g/L, 80°C). [•] Non-porous carbon blacks without mineral impurities are efficient and stable catalysts. [•] Low adsorption capacity prevents carbon deactivation by adsorbed oligomer by-products. [•] Total phenol conversion with 100% efficiency of H2O2 consumption was achieved in 20h. [ABSTRACT FROM AUTHOR]

Abstract: Active oxygen species for soot oxidation over Ag/ZrO2 were characterized by means of X-ray photoelectron spectroscopy (XPS) and temperature-programmed desorption and reduction methods. The temperature-programmed surface reaction (TPSR) between carbon black (CB), a model soot, and surface oxygen revealed that two kinds of adsorbed oxygen species were involved in CB oxidation over Ag/ZrO2. The results of XPS, temperature-programmed desorption of O2, and temperature-programmed reduction by H2 were insufficient to distinguish the two kinds of active oxygen species. Temperature-programmed reduction by NH3 (NH3-TPR) resulted in N2 and N2O formation as products of reduction of the Ag/ZrO2 surface and bulk oxygen. The N2O formation profile in NH3-TPR exhibited two peaks, corresponding to two kinds of oxygen species having a strong oxidation capacity. The effect of Ag loading on the total amount of N2O formation was in good agreement with that on the amount of active oxygen species observed by TPSR-CB. We concluded that NH3-TPR was an appropriate technique for quantitative characterization of the amount of active oxygen species for soot oxidation on Ag/ZrO2. [Copyright &y& Elsevier]

Abstract: Electrocatalysts consisting of polypyrrole (PPY) and Co deposited on carbon black (CB) at several compositions were prepared and tested for the oxygen reduction reaction (ORR) in a HClO4 buffer (pH=1) using a rotating ring-disk electrode (RRDE). It was determined that the most favorable catalyst composition (prior to calcination) had a CB:PPY weight ratio of 2 and a pyrrole:Co (i.e., PY:Co) molar ratio of 4. This catalyst had an onset potential of 0.785V (vs. RHE) and a mass activity of ca. 1A/gcata at the fuel cell relevant voltage of 0.65V. Furthermore, it was found that the number of electrons exchanged during the ORR with the catalyst was ca. 3.5 and resulted in 28% yield of H2O2 at 0.65V, which hints to an indirect 4e − reduction of O2 to H2O, with H2O2 as an intermediate. From energy dispersive spectroscopy (EDS) and extended X-ray absorption fine structure (EXAFS) analysis, it is proposed that a PY:Co ratio of 4 favors the formation, prior to calcination, in the catalyst precursor of Co–N complexes in which Co is coordinated to 3 or 4 N atoms, resulting in strong Co–N interactions that limit the formation upon calcination of low ORR activity Co nanoparticles. These Co–N complexes give rise upon calcination to CoN x−2 sites in which the coordination of Co could favor the adsorption on them of O2, which would make those sites particularly active and selective. At the same mass activity of 1A/gcata, the voltage yielded by the catalyst was 200mV lower than that for a state-of-the-art Pt (10wt.%) catalyst, whose H2O2 output at 0.85V was 39% and involves the exchange of 3.2e −, overall making our material an attractive substitute to noble metal ORR electrocatalysts. [Copyright &y& Elsevier]

Abstract: Pd/C and Pd–Co/C catalysts were synthesized through a simple simultaneous reduction reaction with sodium borohydride in aqueous solution, and the electrocatalytic performance for methanol oxidation in alkaline solutions was investigated. The structure and morphology of these catalysts were characterized by X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDX) and transmission electron microscopy (TEM). The cyclic voltammetry (CV) and CO stripping results show that Pd–Co(8:1)/C has better electrocatalytic activity and higher resistance to CO poisoning over Pd/C, which can be explained by a bifunctional mechanism. Based on the good electrocatalytic performance of Pd–Co(8:1)/C, the ball-milled CNTs-supported Pd–Co(8:1) catalyst was synthesized, demonstrating even better catalytic activity. The high specific surface area of ball-milled CNTs with plenty of mesopores and defects may contribute to the high Pd–Co utilization and consequently to the better electrocatalytic activity. [ABSTRACT FROM AUTHOR]

Abstract: Photocatalytic oxidation of ethanol was carried out in a non-biased photoelectrochemical cell at high pH. The cell was made of two compartments separated by a silica frit, both filled with aerated NaOH electrolyte. The anode electrode bore multilayer nanocrystalline titania, made of either commercial Degussa P25, sol–gel synthesized titania or both. The cathode electrode was made of carbon cloth carrying Carbon Black and Pt as catalyst. When the anode was excited by UVA radiation (363nm), the cell produced electricity very efficiently. The open-circuit voltage was 0.88V in the absence and almost 1.2V in the presence of ethanol. The current increased by more than an order of magnitude by adding ethanol, showing that it is much more efficient to oxidize ethanol than to oxidize (split) water. The performance of the cell improved when a compact titania layer was introduced between the FTO electrode and the thick photocatalytic layer. Ethanol was used as a model fuel but the cell can run on many other organic substances as well. The cell can be used as a source of renewable electricity, by consuming organic wastes under photo-excitation, thus making a PhotoFuelCell. [ABSTRACT FROM AUTHOR]

Abstract: Carbon black (Vulcan XC72R)-supported palladium–vanadium electrocatalysts for the oxygen reduction reaction (ORR) were synthesized by wet chemical reduction of metal chloride salts. The nominal compositions of the electrocatalysts were 60:40, 70:30 and 80:20 (Pd/V atomic ratio). The electrocatalysts were treated at a range of temperatures in 10% H2 in Ar and the effect of heat treatment on particle morphology was characterised using powder X-ray diffraction and transmission electron microscopy. These analyses showed that high temperatures caused an increase in the average particle size. The electrocatalytic activities of the electrocatalysts for the ORR were determined using rotating disk electrode voltammetry, which revealed a marked enhancement in the electrocatalytic activity of the Pd70V30 electrocatalyst after heat treatment. The electrochemical stability of the electrocatalysts was examined using an accelerated stability test, which showed a loss of electrochemical surface area upon electrochemical cycling, the extent of which depended on the nominal composition of the electrocatalysts. Electrocatalyst testing after the stability test showed a loss of electrocatalytic performance and microscopic analysis revealed significant morphological changes in the electrocatalyst particle dimensions and dispersion on the carbon support after the stability test. [Copyright &y& Elsevier]

Abstract: The influence of the structure and morphology of PtRu nanoparticles supported on functionalized carbon black has been investigated for CO and methanol electrooxidation in a half-cell and in a DMFC single cell. Carbon black was treated with HNO3 to obtain an oxidized surface (Vulcan-N), and PtRu nanoparticles supported on Vulcan-N were prepared via impregnation, Bönnemann''s method and the sulfito-complex route. Temperature programmed reduction (TPR) measurements evidence the presence of RuO2·xH2O phase in the catalyst obtained by the sulfito-complex route. This phase was stabilized by metal–support interaction, whereas alloy characteristics were estimated for PtRu catalyst obtained by impregnation and Bönnemann''s method. The nature of the precursor–support interaction, induced by the nature of the functional groups on the carbon surface, affects the structure of the electrocatalyst and subsequent behavior in electroactivity. When synthesized through Bönnemann''s method, the surface oxygen-containing groups of the support seem to be unable to stabilize the anhydrous precursors of platinum and ruthenium, yielding crystalline RuO2. Methanol electrooxidation performance was clearly different in the three catalysts, whereas only a few negligible differences were observed in CO oxidation. The superior performance in DMFC of the catalysts obtained by the sulfito-complex route accounts for both the presence of RuO2·xH2O species and the functionalization of carbon black. [Copyright &y& Elsevier]

Abstract: Ru/CeO2 catalysts with Ru loading of 1–5wt.% were prepared by wet impregnation from aqueous ruthenium (III) nitrosyl nitrate solution and activation with an air flow at 600°C for 4h. This activation resulted in a considerable reactivity for the catalytic oxidation of carbon black (CB) (T 50% ∼350°C “tight contact” mixtures and T 50% ∼515°C “loose contact” mixtures) and volatile organic compounds (VOCs) (T 50% =175°C for propene, T 50% =215°C for toluene). When carbon black oxidation was conducted under “propene (6000ppm)+air” or “toluene (2000ppm)+air” flow, the elimination of an important part of CB was observed at relatively low temperatures comparing to its elimination under pure air flow. These temperatures correspond to the total oxidation of the VOC present in the reactant gases. Carbon black total elimination was also investigated under isotherm conditions in the presence and in the absence of propene. Total elimination occurred during shorter times when combustion was performed under propene. TPR study showed that ruthenium species present in the catalysts after activation reduces at relatively low temperatures (<100°C) and that from a Ru loading of 1.5wt.%, agglomerated ruthenium oxide was formed and that this latter is more difficult to reduce (>100°C). [Copyright &y& Elsevier]

A comprehensive understanding on the selectivity toward electrocatalytic hydrogenation products of nitrobenzene was conducted experimentally and theoretically over a Cu3Pt/C alloying catalyst, revealing the significant role of the applied reduction potential and pH of electrolyte solution in regulating the product selectivity of nitrobenzene hydrogenation. [Display omitted] • High-efficiency Cu x Pt y /C alloying catalysts were fabricated for selective electrocatalytic hydrogenation of nitrobenzene. • The experimental and theoretical studies reveal Cu 3 Pt/C with superior electrocatalytic activity toward Ph-NO 2 hydrogenation. • The DFT calculations provide a comprehensive understanding on the selective electrocatalytic Ph-NO 2 hydrogenation mechanisms. We report ultrafine Cu x Pt y alloying nanoparticles anchored on carbon black (Cu x Pt y /C) for selective electrocatalytic hydrogenation of nitrobenzene (Ph-NO 2) at ambient conditions. The experimental and theoretical studies reveal that as electrocatalyst, the optimal Cu 3 Pt/C with adjusted electronic structure can effectively facilitate the adsorption and activation of Ph-NO 2. The results indicate that the acidic media is favorable for the production of aminobenzene irrelevant to the applied potential, while the electrocatalytic hydrogenation products are highly dependent on the reduction potential in the alkaline media. As a result, the Cu 3 Pt/C can afford almost 100 % conversion of Ph-NO 2 into azoxybenzene with ∼99 % selectivity at 0.3 V (vs. RHE) and aminobenzene with ∼99 % selectivity at -0.3 V (vs. RHE) in 1.0 M KOH, respectively. The theoretical calculations provide a comprehensive understanding of the selective electrocatalytic hydrogenation mechanisms of Ph-NO 2 relative to electrolyte pH and applied potential, matched well with the experimental results. [ABSTRACT FROM AUTHOR]

[Display omitted] • A controlled evolution of micro and mesopores improves the Fe-N x site density. • NO-stripping showed the improvement of both site density and TOF. • The % of active iron increases in samples showing higher mesopores content. • Micro and meso pore are important either in site formation or site accessibility. Fe-N-C have emerged as one of the best non-PGM alternatives to Pt/C catalysts for the electrochemical reduction of O 2 in fuel cells. In this work, we explore the effect of steam and CO 2 treatments at high temperatures on the nanometric porous structure of a commercial carbon black. Using those support materials, we synthesize different Fe-N-C catalysts to achieve a better understanding on the role of micro- and mesopores of the support towards catalytic site formation and site activity. Different time and temperature of treatments result in an almost linear increment of surface area and microporous volume, which allows better nitrogen functionalization. Site density evaluation, performed using a recently described NO-stripping technique, showed an increase in site density and TOF which correlates well with the morphology variation. The percentage of active iron increases from 2.65 % to 14.74 % in activated catalysts confirming a better access of electrolyte to the iron sites. [ABSTRACT FROM AUTHOR]

• Homogenous FeNi alloy catalysts with different atomic ratios were obtained by simple sol-gel method. • Synergistic effect in the FeNi alloy suppresses the oxidation of the Fe and Ni surface in the air. • Fe activates Ni atoms for efficient selective hydrogenation of glucose to sorbitol. • Synergistic effect only arises in FeNi alloy catalyst not in a mixture of Fe and Ni catalysts. Carbon black (CB) supported Ni, Fe, or Fe-Ni alloy catalysts were synthesized by sol-gel to elucidate the reaction pathways over each catalyst, as well as synergistic effects in glucose to sorbitol hydrogenation. The bimetallic materials presented small and alloyed nanoparticles that were richer in reduced metallic sites at the surface than their monometallic counterparts. Glucose isomerization to fructose was favoured over Fe/CB, while glucose hydrogenation to sorbitol is the dominating pathway over Ni/CB catalyst. By contrast, sorbitol production was promoted and undesired isomerization was suppressed when Fe and Ni formed a nanoalloy. In addition, the alloy catalyst presented better stability than the corresponding monometallic catalyst. A comparison with a mechanical mixture of Fe/CB and Ni/CB monometallic catalysts demonstrated the synergy at the nanoscale in the alloy. By comparing different Fe:Ni ratios, the 1:1 formulation was identified as the best compromise to achieve a high activity while maintaining high sorbitol selectivity. [ABSTRACT FROM AUTHOR]

• The Pd/NCB@NGS with unique 3D hierarchical architecture was fabricated by facile strategy. • The size of Pd NPs on NCB@NGS can be controlled without surfactant. • The Pd/NCB@NGS reveals impressive electrochemical EOR performance. • The exciting EOR behavior is owing to the prominent roles of unique 3D hierarchical architecture with abundant N atoms. The engineering efficient electrocatalysts with low cost, high activity and robust durability for ethanol oxidation reaction (EOR) is vital for large-scale commercializing direct ethanol fuel cells. Herein, the "surface-clean" Pd nanoparticles anchored on the nitrogen-doped carbon black embedding nitrogen-doped graphene (Pd/NCB@NGS) with unique three-dimensional hierarchical architecture was fabricated through a self-assembly strategy followed by a surfactant-free chemical reduction. The size of Pd nanoparticles on NCB@NGS can be controlled without surfactant. As an electrocatalyst for EOR, the Pd/NCB@NGS displays improved electrocatalytic performance compared with commercial Pd/C and other counterparts, due to the prominent roles of unique three-dimensional hierarchical architecture with abundant nitrogen atoms. Particularly, the electrocatalytic EOR property of Pd/NCB@NGS-2 (the mass ratio of OCB/GO is 1:1) is optimal among the tested-electrocatalysts, owing to it balances the clash between increased nitrogen atoms and decreased electrical conductivity. This study also developed a superior carbon-based material for various electrocatalysts and beyond. [ABSTRACT FROM AUTHOR]

• Nickel-nitrogen doped carbon catalyst enables efficient CO 2 electroreduction. • Co-electrolysis of CO 2 and KCl aqueous solution produces KHCO 3 , CO, and Cl 2. • A continuously operating system collects formed KHCO 3 in a precipitate tank. • The system achieves high CO 2 conversion. Typically, CO 2 electroreduction is coupled with oxygen evolution reaction (OER), which is highly energy consuming, and also costs alkalis formed at the cathode. Here, we use chlorine evolution reaction (CER), instead of OER, to integrate with CO 2 electroreduction mediated by an efficient metal-nitrogen doped carbon catalyst derived from the mixture of nickel porphyrin and commercial carbon black. The combined system was evaluated in two electrolyzer configurations that have been adopted in the chlor-alkali process to produces CO, Cl 2, and KHCO 3 simultaneously. To allow continuous operation, we designed a continuously operating system to collect produced KHCO 3 in a precipitate tank with improved techno-economics and efficient CO 2 utilization. Also, it could serve as an environmental-friendly alternative to the Solvay process for soda production. This work may provide a new strategy for the design of CO 2 electrolysis systems with better economic viability. [ABSTRACT FROM AUTHOR]

• HCB-Ni-Au bimetallic nanocatalysts are prepared for nitroaromatics hydrogenation. • Experiments and DFT are creatively combined to explore the catalytic efficiency. • Nitroaromatics are reduced by cleavage of N O and N N bonds, uptake of H from Ni H and Au H bonds. • Reaction rate of 4-NP by HCB-N 6 -Au 1 is 15 and 38 times higher than that of HCB-Ni 6 and HCB-Au 1. HNO 3 -modified carbon black supported Ni-Au bimetallic nanocatalysts (HCB-Ni-Au) with different Ni/Au molar ratio were synthesized for hydrogenation of nitroaromatics. The synergistic effect between bimetallic nanoparticles and HCB, Ni and Au nanoparticles improved the catalytic efficiency. The reaction mechanism and pathway investigation exhibited that nitroaromatics were reduced by cleavage of N O bond and azo linkage (N N) and uptake of H from Ni H and Au H bonds. Density functional theory theoretical calculation showed 4-nitrophenol (4-NP) with higher free energy was easier to be catalyzed. The activation of enthalpy for MO was 65.7 kcal mol−1, which displayed the highest catalytic rate of 2.1055 min−1. Meanwhile, the reaction rate of 4-NP hydrogenation catalyzed by HCB-Ni 6 -Au 1 reached 1.9617 min−1, which was 15 and 38 times higher than that of Ni and Au monometallic nanocatalyst, respectively. HCB-Ni 6 -Au 1 with good structural stability could be well reused and applied in tap, distilled, river, and lake water samples. [ABSTRACT FROM AUTHOR]