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[Display omitted] The quest for efficient hydrogen production highlights the need for cost-effective and high-performance catalysts to enhance the electrochemical water-splitting process. A significant challenge in developing self-supporting catalysts lies in the high cost and complex modification of traditional substrates. In this study, we developed catalysts featuring superaerophobic microstructures engineered on microspherical nickel-coated Chinese rice paper (Ni-RP), chosen for its affordability and exceptional ductility. These catalysts, due to their microspherical morphology and textured surface, exhibited significant superaerophobic properties, substantially reducing bubble adhesion. The nickel oxy-hydroxide (NiO x H y) and phosphorus-doped nickel (PNi) catalysts on Ni-RP demonstrated effective roles in oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), achieving overpotentials of 250 mV at 20 mA cm−2 and 87 mV at −10 mA cm−2 in 1 M KOH, respectively. Moreover, a custom water-splitting cell using PNi/Ni-RP and NiO x H y /Ni-RP electrodes reached an impressive average voltage of 1.55 V at 10 mA cm−2, with stable performance over 100 h in 1 M KOH. Our findings present a cost-effective, sustainable, and easily modifiable substrate that utilizes superaerophobic structures to create efficient and durable catalysts for water splitting. This work serves as a compelling example of designing high-performance self-supporting catalysts for electrocatalytic applications. [ABSTRACT FROM AUTHOR]

In this study, hydrogen harvesting from fermentation of sugarcane bagasse (SCB) was promoted by maintaining synergism between sulfonated graphene (SGR) catalyst and paper mill sludge (PMS). The sulfonic acid (–SO 3 H) groups in the catalyst played a major role in destructing the β-1,4 glycosidic bonds of sugarcane bagasse, releasing readily biodegradable sugars into the fermentation medium. The cellulose, hemicellulose, and lignin conversion efficiency were improved by 127.5%, 495.0%, and 109.2%, respectively with 20 mgSGR/gVS catalyst addition, compared with the control samples. These values were also higher than those obtained by non-sulfonated graphene catalyst. The hydrogenation of sugarcane bagasse was maximized at a sulfonated graphene catalyst dosage of 60 mgSGR/gVS, providing the highest hydrogen harvesting of 4104 ± 321 mL. This was associated with an increase of the Proteobacteria phyla up to 52.0%, Firmicutes phyla to 13.9%, and Acinetobacter sp. to 39.8% compared with only 37.0%, 11.3% and 11.1% in the control assay respectively. Moreover, sulfonated graphene catalyst supplementation promoted the acetate fermentation reaction pathway by increasing the acetate/butyrate ratio up to 4.1. Nevertheless, elevating the catalyst dosage up to 120 mgSGR/gVS reduced the hydrogen harvesting (1190 ± 92 mL) due to the release of furfural (1.76 ± 0.02 g/L) in the fermentation cultures, deteriorating the microbes' internal composition and metabolism bioactivities. Finally maximizing the hydrogen productivity from sugarcane bagasse is feasible by incorporation of paper mill sludge and sulfonated graphene catalyst at dosage not exceeding 60 mgSGR/gVS. However, investigating the recyclability and disposal of digestate containing sulfonated graphene catalyst and the associated economic feasibility needs more attention in the future. [Display omitted] • Sugarcane bagasse was fermented by paper mill sludge supported on sulfonated graphene. • Synergism between paper mill sludge/sulfonated graphene improved bio-H 2 by 4.8 times. • Sulfonated graphene promoted acetate fermentation (HAc/HBu of 4.1) and inhibited HPr. • Acinetobacter degrading phenol increased by 3.6 folds with sulfonated graphene catalyst. • MolDock visualized H-bonding in hydrogenase protein/sulfonated graphene interaction. [ABSTRACT FROM AUTHOR]

Co 3 O 4 catalysts supported on paper-like stainless steel fibers (PSSF) were prepared by MOFs-templated (M) method and applied for catalytic combustion of isopropanol. Physicochemical properties of the as-synthesized Co 3 O 4 catalysts were investigated by SEM, EDS mapping, TEM, XRD, BET, XPS and H 2 -TPR, respectively. Characterization results of SEM and TEM shown that Co 3 O 4 (M)-350 and Co 3 O 4 (M)-400 still remained the dodecahedron shape of the ZIF-67 precursor and possessed porous structures. The XPS results shown that the ratio of Co3+/Co2+ and O c /O c ​+ ​O a ​+ ​O l firstly increased and then decreased with the increase of calcination temperature. Among the as-synthesized catalysts, Co 3 O 4 (M)-400 exhibited the highest activity for the catalytic combustion of isopropanol with the T 50 and T 90 values of 258 ​°C and 281 ​°C, respectively, which was associated with high BET surface area, high amount of Co3+ species and abundant surface chemisorbed oxygen. Moreover, Co 3 O 4 (M)-400 was employed as a structured catalyst for isopropanol combustion, the catalytic kinetics were studied based on different feed concentration, bed height and GHSV. The experimental results indicated that the T 50 and T 90 of isopropanol combustion over Co 3 O 4 (M)-400 with the bed height of 2 ​cm were increased slightly as the GHSV and feed concentration of isopropanol increased. Fig. 1 Preparation process and Catalytic performance of Catalysts. [Display omitted] • A novel gradient porous Co 3 O 4 (M)-X catalyst was prepared by MOFs-templated method. • The effect of preparation methods on properties of Co based catalysts were studied. • Co 3 O 4 (M)-400 shown the highest isopropanol catalytic combustion performance. [ABSTRACT FROM AUTHOR]

As a high-active metal-free electrocatalyst for NH 3 production via NO reduction reaction, honeycomb carbon nanofiber achieves an NH 3 yield of 22.35 μmol h−1 cm−2 with a high Faradaic efficiency of 88.33%. [Display omitted] Electrocatalytic NO reduction is a promising technology for ambient NO removal with simultaneous production of highly value-added NH 3. Herein, we report that honeycomb carbon nanofiber coated on carbon paper acts as an efficient metal-free catalyst for ambient electroreduction of NO to NH 3. In 0.2 M Na 2 SO 4 solution, such catalyst achieves an NH 3 yield of 22.35 μmol h−1 cm−2 with a high Faradaic efficiency of up to 88.33%. Impressively, it also shows excellent stability for 10-h continuous electrolysis. Theoretical calculations reveal that the most active center of functional groups is –OH group for NO reduction with a low energy barrier (ΔG of 0.29 eV) for the potential-determining step (*NO + H → *HNO). [ABSTRACT FROM AUTHOR]

[Display omitted] • The catalytic ozonation performances for seven CeO 2 catalysts with different morphologies and exposed facets are disclosed. • CeO 2 nanorods with (1 1 0) and (1 0 0) facets exposed show the best performance. • A linear relationship between Frenkel-type OV density and O 3 decomposition rate is revealed regardless of morphology and exposed facet. • DFT calculation and experimental data reveal OV boosts O 3 activation on both the Ce and hydroxyl sites of CeO 2. Morphology and facet effects of metal oxides in heterogeneous catalytic ozonation (HCO) are attracting increasing interests. In this paper, the different HCO performances for degradation and mineralization of phenol of seven ceria (CeO 2) catalysts, including four with different morphologies (nanorod, nanocube, nanooctahedron and nanopolyhedron) and three with the same nanorod morphology but different exposed facets, are comparatively studied. CeO 2 nanorods with (1 1 0) and (1 0 0) facets exposed show the best performance, much better than that of single ozonation, while CeO 2 nanocubes and nanooctahedra show performances close to single ozonation. The underlying reason for their different HCO performances is revealed using various experimental and density functional theory (DFT) calculation results and the possible catalytic reaction mechanism is proposed. The oxygen vacancy (OV) is found to be pivotal for the HCO performance of the different CeO 2 catalysts regardless of their morphology or exposed facet. A linear correlation is discerned between the rate of catalytic decomposition of dissolved ozone (O 3) and the density of Frenkel-type OV. DFT calculations and in-situ spectroscopic studies ascertain that the existence of OV can boost O 3 activation on both the hydroxyl (OH) and Ce sites of CeO 2. Conversely, various facets without OV exhibit similar O 3 adsorption energies. The OH group plays an important role in activating O 3 to produce hydroxyl radical (∙OH) for improved mineralization. This work may offer valuable insights for designing Facet- and OV-regulated catalysts in HCO for the abatement of refractory organic pollutants. [ABSTRACT FROM AUTHOR]

In this paper, Fe-N 3 S 1 and FeS sub-nano cluster are innovatively connected to S, N co-doped carbon matrix (SNC) by controlled calcination process. The local electron configuration of Fe center is modulated by this unique structure. Based on this design, Fe-N 3 S 1 and FeS sub-nano cluster shown excellent synergistic effects in oxygen reduction reaction. The optimized ORR activity was obtained. [Display omitted] Single atomic Fe-N 4 catalyst exhibits a great prospect for oxygen reduction reaction (ORR) and adjusting the intrinsic coordination structure and the carbon matrix structure effectively improves the catalytic activity. However, controlling the active site coordination structure and its surrounding environment at atomic level remains a challenge. In this paper, Fe-N 3 S 1 and FeS sub-nano cluster were innovatively concatenated on S, N co-doped carbon matrix (SNC), denoted as FeS/FeSA@SNC catalysts, for modulating ORR catalysis performance. Both experimental measurements and theoretical calculations have confirmed that the local electron configuration of Fe center is modulated by this unique structure combination leading to optimized ORR kinetics. Based on this design, the synthesized FeS/FeSA@SNC delivers ORR activity with a half-wave potential of 0.9 V (vs. RHE), excelling that of commercial Pt/C (0.87 V) and the Zn-air battery (ZAB) with this cathode catalyst delivers a peak power density of 126 mW cm−2. This work presents a novel strategy for manipulating the single-atom active sites through control the local coordination structure and provides a reference for the development of novel efficient ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • There is no reported work on 3D printed catalysts for biomass-biooil conversion applications. To fill this gap, this paper reviewed the key technologies that will be needed including 1) typical catalysts used for biomass conversion applications, 2) 3D printed catalysts, and 3) design and optimization of structured catalysts. • Desired catalysts performance in current biomass-biooil conversion research is mostly achieved by altering catalyst material composition rather than structural properties. • 3D printed catalysts research is still in its infancy and lacks full considerations of the design potentials of 3D printing, such as hierarchical complexity and material complexity. • Current work on design and optimization of structured catalysts shows deficiency in manufacturing constraints, for example, resolution of 3D printers, which may lead to coke formation issues in catalytic process. The devastative effects of traditional fossil fuel consumption have made biomass (e.g., plants, wood, and waste) a widely used renewable source of energy. The variety in biomass properties makes tunable catalysts an essential ingredient to promote reactions for desired molecule outputs. Catalysts with optimal catalytic performance are typically structured with complicated morphology, such as high porosity and sophistic pore network, which makes it challenging for catalyst fabrication. Recent progress in utilizing 3D printing as the fabrication method has demonstrated great potential of handling the complex structure while improving catalytic performance; however, rare work has focused on biomass-bio-oil conversion (BBC). With the aim of developing the optimal structured catalysts for BBC applications, this paper particularly reviewed 1) typical catalysts used for biomass conversion applications, 2) 3D printed catalysts, and 3) design and optimization of structured catalysts. It is found that the BBC is often isolated from manufacturing and focused more on different catalyst composition with transition metals to provide the desired catalyst architecture and further to improve upgrading of the BBC product. Current work on 3D-printed catalysts also show deficiency in several aspects including formation of coke and catalyst deactivation, lack of a comprehensive design for the catalyst structure (e.g., mostly 2D structures), absence of manufacturing constraints in design operation, and insufficient resolution of 3D printing methods. To solve these issues, several potential research directions and opportunities are discussed at the end of the study. [ABSTRACT FROM AUTHOR]

[Display omitted] • PtRu catalysts composed of Pt and RuO 2 are synthesized via cyclic electrodeposition. • PtRu catalyst shows unprecedented performance for ECH of phenol to cyclohexanol. • PtRu catalyst possesses outstanding reusability in acidic electrolyte. • The activation of phenol is observed via in situ Raman spectroscopy. • The direct reduction mechanism with proton-coupled electron transfer is proposed. Electrocatalytic hydrogenation (ECH) of phenol has been recognized as a promising route towards facile and green production of cyclohexanol. However, the practical application is hindered by product selectivity and catalyst durability. Herein, a series of PtRu electrocatalysts composed of metallic Pt0 and RuO 2 species are in situ fabricated on carbon paper via cyclic electrodeposition, showing outstanding activity and stability for ECH of phenol. At ambient temperature and a current density of 10 mA cm−2, the optimal Pt3Ru3 catalyst achieves a 100 % selectivity to cyclohexanol at a 100 % conversion of phenol in 0.1 M H 2 SO 4. At 100 mA cm−2, Pt3Ru3 achieves an outstanding faradaic efficiency of ∼87 % and a cyclohexanol production of 52.6 mg cm−2 h−1. Two parallel ECH pathways from phenol to cyclohexanol are identified. In situ Raman spectroscopy and kinetic study reveal that phenol could be hydrogenated over Pt3Ru3 in acidic electrolyte via proton-coupled electron transfer with the destruction of conjugated π bond of aromatic ring. This work offers an effective approach for facile construction of durable electrode material and an efficient electrochemical strategy for phenol hydrogenation. [ABSTRACT FROM AUTHOR]

[Display omitted] • Bifunctional catalyst Fe[ Pc (I) 4 ] + Ni[ Pc (I) 4 ]@NC PDI for ORR and OER is synthesized. • The NC PDI with 2D structure and superior stability was used as support. • Iodine groups in TM[ Pc (I) 4 ] creates a built-in electric field to enhance catalysis. • The synergistic effect of Fe[ Pc (I) 4 ]/Ni[ Pc (I) 4 ] enhances the catalytic performance. • The catalyst has superior performance for ORR/OER in rechargeable Zn-air batteries. In this paper, we report on the preparation and catalysis of a bifunctional molecular catalyst (Fe[ Pc (I) 4 ]+Ni[ Pc (I) 4 ]@NC PDI) for oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) in rechargeable Zn-air batteries. This catalyst is prepared by self-assembling tetraiodo metal phthalocyanines (Fe[ Pc (I) 4 ] and Ni[ Pc (I) 4 ]) on a 2D N -doped carbon material (NC PDI) through π-π interactions. The introduction of iodine groups in the edge of phthalocyanines controls the density of electron cloud and electrostatic potential around Fe-N/Ni-N sites and constructs a built-in electric field that facilitates directional transport of charges, enhancing the catalytic activity of the catalyst. Density functional theory (DFT) calculations support this mechanism by showing a reduced energy barrier for the ORR rate-determining step (RDS). The Fe[ Pc (I) 4 ]+Ni[ Pc (I) 4 ]@NC PDI exhibits excellent performance outperforming 20 wt% Pt/C and single-molecule self-assembled Fe[ Pc (I) 4 ]@NC PDI and Ni[ Pc (I) 4 ]@NC PDI , with a half-wave potential of E 1/2 = 0.940 V in the ORR process under alkaline condition. During the OER process, Fe[ Pc (I) 4 ]+Ni[ Pc (I) 4 ]@NC PDI exhibited a low overpotential of 298 mV at 10 mA cm−2 under the alkaline condition, which is much better than RuO 2 , Fe[ Pc (I) 4 ]@NC PDI and Ni[ Pc (I) 4 ]@NC PDI. The catalyst also demonstrates excellent catalysis and durability in rechargeable Zn-air batteries. This work provides a simple and specific method to develop efficient multifunctional molecular electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] • The adsorption energies of CO 2 on the surface oxygen vacancies of different crystalline In 2 O 3 were calculated using DFT. • The effect of the spatial distributions of two active components on the CO 2 hydrogenation to aromatics was studied. • The acidity of catalyst under different spatial distributions was studied through NH 3 -TPD. In tandem catalysts, not only good synergy between the two active components is required, but also the precise control of the spatial distribution between the two active components of metal oxides and zeolite is crucial for the migration and conversion of reaction intermediates in the direct conversion of CO 2 to hydrocarbons. The correlation between the metal and the acidic site of zeolite has traditionally been simplified as "the closer, the better". However, it should be noted that this principle only holds true for a portion of tandem catalysts. Therefore, this paper studied the effect of different crystalline In 2 O 3 (cubic phase, hexagonal phase, and mixed cubic/hexagonal phase) and sheet HZSM-5 zeolite tandem catalysts on the activity of CO 2 hydrogenation reaction under different spatial distribution. The generalized gradient approximation (GGA) of density functional theory (DFT) were used to simulate the adsorption energy of CO 2 by oxygen vacancy on c-In 2 O 3 (1 1 1) and h-In 2 O 3 (1 0 4) planes, it was found that O v1 on c-In 2 O 3 (1 1 1) and O v4 on h-In 2 O 3 (1 0 4) had the strongest adsorption energy for CO 2. In addition, it has been observed that the proximity of the two active components (e.g., during mortar mixing) results in decreased catalytic performance. This is due to the migration of metal In, which neutralizes the acid sites of zeolites and leads to inefficient conversion of methanol reaction intermediates to aromatics. As a result, CO 2 conversion and aromatic selectivity are decreased. [ABSTRACT FROM AUTHOR]

[Display omitted] • Understanding the dynamic evolution of catalysts under reaction condition is critical to rational design of catalysts and control of catalytic properties, yet presents great challenges to both experimental and computational techniques. • Here we report an original study that aims to advance the fundemental understanding of the dynamic change of an supported Cu catalyst and the corresponding catalytic property during electrochemical reduction of CO 2 to ethanol by a comprehensive structural and mechanistic study. • This study integrates in-situ X-ray absorption near edge structure (XANES) spectroscopy with ab initio XANES simulations to identify the structural changes of the catalyst, combined with systematic density functional theory (DFT) caclulations of reaction mechanism on various catalytic sites. • The evolution of single-atom Cu to Cu nanoparticles under electrochemical condition has been identified, and Cu partcile size effect on activity and product selectivity is demonstrated. This work also demonstrates an effective strategy on studying the dynamic evolution of catalysts. Direct electrochemical conversion of CO 2 to ethanol (CH 3 CH 2 OH) offers a promising strategy to lower CO 2 emission while storing energy from renewable electricity. Our recent study reported a carbon-supported atomically dispersed Cu catalyst that achieved the highest reported selectivity for CH 3 CH 2 OH formation (91%) at a relatively low potential (-0.6 V), however, the active site structure that is responsible for such high activity and selectivity has yet to be understood. In this paper, we demonstrate a computational investigation combining X-ray absorption near edge structure (XANES) simulations and a mechanistic study via density functional theory (DFT) to understand the catalyst structures of this Cu catalyst during electrocatalysis and the corresponding reaction mechanisms of the key products. An integrated computational and experimental XANES analysis depicted the dynamic evolution of the catalytic site during electrocatalysis. The as-prepared, atomically dispersed Cu catalyst aggregates and forms metallic clusters/nanoparticles under electrochemical condition, which then break down to smaller oxidized clusters after electrocatalysis. The formed Cu clusters/nanoparticles showed distinct catalytic activity and selectivity as a function of particle size based on the mechanistic investigation using DFT, which is consistent with experimental observations for catalyst samples with different Cu loadings. This comprehensive study which combines experimental and computational XANES investigation, mechanistic study via DFT calculations, and experimental performance of the catalysts, provides unprecedented dynamic and mechanistic insights into the supported atomically dispersed metal catalysts for CO 2 reduction. Such strategy and details gained can further guide discovery of novel catalyst materials for CO 2 electrochemical reduction. [ABSTRACT FROM AUTHOR]

N -doped porous carbon monatomic iron catalysts (Fe SA /NPCs) obtained by polydopamine modification strategy were used for high efficiency oxygen reduction reactions and zinc-air batteries. [Display omitted] • Nitrogen doped porous carbon materials (NPCs) were prepared based on ZIF-L. • Stable hollow leaf-like morphology was maintained by coating PDA and nitrogen content was adjusted. • Fe SA was easily anchored on NPCs with luxuriant anchoring sites. • Fe SA /NPCs shows excellent electrochemical performance in oxygen reduction and zinc air batteries. Metal-nitrogen-carbon (M N C) catalysts, especially Fe N C catalysts, are considered promising candidates to replace Pt-based catalysts, but Fe N C catalysts still present certain challenges in controlled-synthesis and energy device applications. In this paper, through the modification strategy of poly-dopamine (PDA) to maintain 2D leaf morphology to obtain more active sites and further adjust the N content, N -doped porous carbon monatomic iron catalyst (Fe SA /NPCs) with rich-nitrogen content was prepared. XPS analysis showed that compared with C-ZIF-Fe, the contents of graphite nitrogen and pyridine nitrogen increased in Fe SA /NPCs. The hollow structure with defects and Fe-N 4 configuration of Fe single atom show more active sites for the catalyst, and positively promote the diffusion of reactants, oxygen exchange and electron transport, thus changing the reaction kinetics and promoting the improvement of ORR activity. Fe SA /NPCs electrocatalyst exhibits good half-wave potential and onset potential at low loading (E 1/2 = 0.93 V, E onset = 1.0 V). In addition, the methanol tolerance, stability and Tafel slope are better than those of commercial Pt/C. Excitingly, the zinc-air cell with Fe SA /NPCs as cathode material achieves a power density of 223 mW cm−2 and exhibits a long-term stability higher than 200 h. This work shows that nitrogen-doped porous carbon materials as well as iron monoatoms play important roles in improving electrocatalytic performance. [ABSTRACT FROM AUTHOR]

A novel single-atom Pt-CeO 2 /Co 3 O 4 catalyst with ultra-low Pt loading capacity (0.06 wt%) was fabricated. The sample presents better catalytic activity, stability and water resistance than the Pt nanoparticle supported catalysts. The excellent properties are attributed to the stronger metal-support interaction (SMSI) between single-atomic Pt and the support, which induces more Pt0, Ce3+ and Co3+ species to participate in the deep oxidation of toluene. [Display omitted] • Single-atom Pt-CeO 2 /Co 3 O 4 catalyst with ultra-low Pt loading (0.06 wt%) and excellent toluene oxidation activities (T 90 = 169 °C) was fabricated. • The ultra-long durability (120 h) of the 0.06Pt-SA was superior to most noble metal single-atomic catalysts reported so far. • Enhanced metal support interaction between single atomic Pt and CeO 2 -Co 3 O 4 carrier induced more Pt0, Ce3+ for oxygen activation and more Co3+ for toluene activation. The design and manufacture of high activity and thermal stability catalysts with minimal precious metal loading is essential for deep degradation of volatile organic compounds (VOCs). In this paper, a novel single-atom Pt-CeO 2 /Co 3 O 4 catalyst with ultra-low Pt loading capacity (0.06 wt%, denoted as 0.06Pt-SA) was fabricated via one-step co-precipitation method. The 0.06Pt-SA exhibited excellent toluene degradation activity of T 90 = 169 °C, matched with the nanoparticle Pt-supported CeO 2 /Co 3 O 4 catalyst with more than six times higher Pt loading (0.41 wt%, denoted as 0.41Pt-NP). Moreover, the ultra-long durability (toluene conversion remains 99% after 120 h stability test) and excellent toluene degradation ability in a wide space speed range of 0.06Pt-SA were superior to that of 0.41Pt-NP catalyst. The excellent performance was derived from the strong metal-support interaction (SMSI) between the single atomic Pt and the carrier, which induced more Pt0 and Ce3+ for oxygen activation and more Co3+ for toluene removal. The in situ diffuse reflectance infrared spectroscopy (DRIFTS) experiments confirmed that the conversion of intermediates was accelerated in the reaction process, thereby promoting the toluene degradation. Our results should inspire the exploitation of noble single-atomic modification strategy for developing the low cost and high performance VOCs catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] Developing efficient and durable bifunctional air–cathode catalysts for both oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) is one of the key efforts promoting the practical rechargeable zinc-air batteries (ZABs). In this paper, high-performance bifunctional air–cathode catalysts by a two-step strategy: atomically dispersed Ni on N -doped carbon is first derived from MOF to form uniformly dispersed NiNC, which are pyrolyzed together with Fe source at different high-temperatures to form FeNi@NC-T (T = 800, 900, and 1000 °C) catalysts. The as-synthesized non-noble metal FeNi@NC-900 catalyst exhibits a considerably small potential gap (ΔE) of 0.72 V between ORR and OER, which is as the same as commercial noble metal Pt/C + Ir black mixed catalyst. The performance of the ZABs using FeNi@NC-900 as the air–cathode catalyst displays a power density of 119 mW·cm−2 and a specific capacity of 830.1 mAh·g−1, which is superior to that of Pt/C + Ir black mixed catalyst. This work provides a guideline for designing alloy electrocatalysts with uniform size and nanoparticle distribution for metal-air batteries with bifunctional air-cathodes. [ABSTRACT FROM AUTHOR]

[Display omitted] As a renewable green energy, hydrogen has received widespread attention due to its huge potential in solving energy shortages and environment pollution. In this paper, a one-step solvothermal method was applied to grow ultra-thin g-C 3 N 4 (UCN) nanosheets and NiS nanoparticles on the surface of ZnIn 2 S 4 (ZIS). A ternary NiS/ZnIn 2 S 4 /ultra-thin-g-C 3 N 4 composite material with dual high-speed charge transfer channels was constructed for the advancement of the photocatalytic H 2 generation. The optimal ternary catalyst 1.5wt.%NiS/ZnIn 2 S 4 /ultra-thin-g-C 3 N 4 (NiS/ZIS/UCN) achieved a H 2 evolution yield reached to 5.02 mmolg−1h−1, which was 5.23 times superior than that of pristine ZnIn 2 S 4 (0.96 mmolg−1h−1) and even outperform than that of the best precious metal modified 3.0 wt%Pt/ZnIn 2 S 4 (4.08 mmolg−1h−1). The AQY at 420 nm could be achieved as high as 30.5%. The increased photocatalytic performance of NiS/ZIS/UCN could be ascribed to the type-I heterojunctions between intimated ZIS and UCN. In addition, NiS co-catalyst with large quantity of H 2 evolution sites, could result in efficient photo-induced charges separation and migration. Furthermore, the NiS/ZIS/UCN composite exhibited excellent H 2 evolution stability and recyclability. This work would also offer a reference for the design and synthesis of ternary co-catalyst with heterojunction composite for green energy conversion. [ABSTRACT FROM AUTHOR]

Schematic diagram of fabricating process of NixSey/MoSe2/NF hollow rod arrays. [Display omitted] Alkaline water electrocatalysis is considered as one of the most reliable method to prepare the stable, inexpensive, and sustainable water splitting catalyst in large-scale. Recently, MoSe 2 attracted great attention as a promising catalyst because of its high electrochemical activity and earth-abundant nature. In this paper, bionic Ni x Se y /MoSe 2 coralline-liked heterogeneous structures were successfully prepared on 3D nickel foam (NF) via a simple solvothermal process complemented by hydrothermal strategy with selenization and alkali treatment. Furthermore, to overcome the less active sites and poor electrical conductivity of MoSe 2 , we learned from the coral structure for the inspiration, and reported a novel hollow rod-like structure with increased active sites. Also, 1 T-2H MoSe 2 improved the electrical conductivity of single phase MoSe 2. We first confirmed the multi-phase of catalyst by XPS analysis with Mo 3d 5/2 splited into two independent regions with the 2H and 1 T phase transition. The optimal ratio of Ni x Se y/ MoSe 2 /NF-5 exhibited excellent electrocatalytic activity towards HER in 1 M KOH, driving current densities of 10, 100 and 200 mA cm−2 at only 76, 165 and 194 mV with stability over 24 h. The work provides new ideas for the construction of transition metal selenides hollow rod array structures of efficient HER electrocatalysts. [ABSTRACT FROM AUTHOR]

[Display omitted] As a promising dopant, electron deficient B atom not only tunes the electronic structure of electrocatalysts for improving their intrinsic catalytic activities, but also combines with hydroxy radical as strong adsorption sites for accelerating the water dissociation during the hydrogen evolution reaction (HER). In this paper, we report an electrocatalyst based on boron-modified Ru anchored on carbon nanotubes (B-Ru@CNT) that shows impressive HER activity in acidic and alkaline media. The boron-rich closo -[B 12 H 12 ]2- borane was selected as a moderately strong reductant for the in situ reduction of a Ru salt, which yielded B-doped Ru nanoparticles. The experimental and theoretical results indicate that the incorporation of B not only weakens the Ru-H bond and downshifts the d-bond centre of Ru from the Fermi level by reducing the electron density at Ru but also accelerates the water dissociation reaction by providing B sites, which strongly adsorb OH* intermediates, and nearby Ru sites, which act as sites for the adsorption of the H* intermediate, thus boosting the HER performance and enhancing the HER kinetics. As a result of the tuning of the electronic structure via B doping, B-Ru@CNT showed excellent HER performance, yielding overpotentials of 17 and 62 mV at a current density of 10 mA cm−2 in alkaline and acidic solutions, respectively. These results indicate that our synthetic method is a promising route to B-doped metallic Ru with enhanced pH-independent HER performance. [ABSTRACT FROM AUTHOR]

On the international level, it is common to act on reducing emissions from energy systems. However, in addition to industrial emissions, low-stack emissions also make a significant contribution. A good step in reducing its environmental impact, is to move to biofuels, including biomass. This paper examines the impact of placing a catalytic system in a retort boiler to minimize emissions of greenhouse gases, dust and other pollutants when burning pellets. The effect of platinum, and oxides of selected metals placed on the deflector as a solid catalyst was studied. Based on the experimental data, a branched artificial neural network was constructed and trained. The routing of three parallel topologies made it possible to achieve high accuracy while keeping the input data relatively simple. The system showed an average error of 3.54% against arbitrary test data. On the basis of experimental data as well as predictions returned by the artificial neural network, recommendations were shown for the catalysts used and their amounts. Depending on the biomass from which the pellet was produced, the experiment suggested the use of titanium or copper oxides. In the case of the neural network, it was able to select a better system, based on platinum, improving emission reductions by up to more than 19%, depending on the type of pellet used. [Display omitted] • Unique three-path-ANN system to simulate catalytic biomass combustion. • High accuracy with MRE of 3.54 % versus unbiased test data. • Bioenergy production from straw, hemp and wood pellets. • Complexed system to forecast 11 different parameters. • Case study indicates optimal catalyst – feedstock pairs. [ABSTRACT FROM AUTHOR]

Photocatalytic Hydrogen production as one of the effective ways to solve the future energy issues has recently become a research hotspot in the field of renewable energy. However, single-component photocatalysts have poor hydrogen production efficiency due to the narrow light-absorption range, susceptibility to photo-corrosion and low catalytic activity. Herein, novel heterojunction photocatalysts of ZnIn 2 S 4 @BiYWO 6 with different mass ratios were designed and synthesized using a facile two-step hydrothermal method. Experimental results and analyses show that these heterojunction catalysts exhibit extremely excellent photocatalytic performance for hydrogen production. Especially, the hydrogen production rate of 10ZnIn 2 S 4 -BiYWO 6 is 73 times higher than that of pure ZnIn 2 S 4. Furthermore, enhanced photocatalytic mechanism and carrier transfer pathway in the heterojunction photocatalyst of ZnIn 2 S 4 @BiYWO 6 were deeply analyzed and explored in the paper, which confirmed that ZnIn 2 S 4 @BiYWO 6 is a direct Z-scheme heterojunction architecture. Within such a Z-scheme framework, the presence of a built-in electric field at the interface between ZnIn 2 S 4 and BiYWO 6 as well as the energy band bending lead to the direct recombination of electrons and holes with low redox capacity, while keeping the electrons and holes with high redox capacity in each component. Consequently, the photocatalytic activity of the Z-scheme heterojunction system has been greatly enhanced. It is believed that the present work provides valuable guidance for the design and construction of novel Z-scheme heterojunction photocatalysts. Z-scheme heterojunctions greatly enhanced photocatalytic hydrogen production efficiency of ZnIn 2 S 4 @BiYWO 6 composites. [Display omitted] • ZnIn 2 S 4 @BiYWO 6 photocatalysts exhibit excellent hydrogen production efficiency. • Z-scheme heterostructures play a key role in enhancing photocatalytic activity. • Such Z-scheme photocatalysts are promising for photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

[Display omitted] • WN nanosheets were prepared by sol–gel method. • CdS/WN was prepared by one pot solvothermal method. • Intimate interfacial contact between CdS NPs and WN engenders Schottk junction. • The evolution rate of optimal CdS/WN H 2 was 9.28 times that of CdS NPS. Based on the strategy that electrocatalysts can be used as additives to improve the performance of photocatalysts, and the unique metalloid properties of tungsten nitride (WN), it can form a Schottky junction with the semiconductor at the heterogeneous interface to improve the photocatalytic performance of semiconductor catalysts. In this paper, WN with excellent electrical conductivity was selected as a new noble-metal-free co-catalyst to improve the photoreduction hydrogen (H 2) evolution performance of CdS nanoparticles (NPs). Firstly, WN nanosheets were prepared by sol–gel method; then, a novel and noble-metal-free heterojunction photocatalyst, which is CdS NPs deposited on the surface of WN, was successfully fabricated via one-pot solvothermal method. Under visible light irradiation, the H 2 production rate of the WN/CdS composite catalyst is 24.13 mmol/g/h, which is 9.28 times that of pure CdS NPs. The observably boosted H 2 generation activity could be ascribed to the broadened visible-light absorption and intimate interfacial contact between CdS NPs and WN engenders Schottky junction. This study provides a novel and cost-effective approach for designing efficient noble-metal-free photocatalysts and improving H 2 evolution activity of CdS under visible-light-driven photocatalytic water splitting. [ABSTRACT FROM AUTHOR]

[Display omitted] • The flooding of GDEs used for CO 2 electrolysis causes unstable electrolyser behavior and, with time, the loss of Faradaic efficiency for CO production. • Flooding is closely related to the formation of potassium carbonate and bicarbonate salts in the GDE structure that causes hydrophobicity loss. • The cross-sectional elemental (K) mapping of GDEs by EDX helps the visualization of K salt penetration inside a GDE structure, but does not allow quantitative comparison. • By combining EDX mapping with ICP-MS based total K content determination, quantitative and comparable depth profiles can be obtained. • The combined EDX/ICP-MS approach is used to study two different GDLs: one with a cracked, and another with a compact microporous layer. • The analysis indicates better water management for the cracked GDL. The most promising strategy to scale up the electrochemical CO 2 reduction reaction (ec - CO 2 RR) is based on the use of gas diffusion electrodes (GDEs) that allow current densities close to the range of 1 A/cm2 to be reached. At such high current densities, however, the flooding of the GDE cathode is often observed in CO 2 electrolysers. Flooding hinders the access of CO 2 to the catalyst, and by thus leaving space for (unwanted) hydrogen evolution, it usually leads to a decrease of the observable Faradaic efficiency of CO 2 reduction products. To avoid flooding as much as possible has thus become one of the most important aims of to-date ec - CO 2 RR engineering, and robust analytical methods that can quantitatively assess flooding are now in demand. As flooding is very closely related to the formation of carbonate salts within the GDE structure, in this paper we use alkali (in particular, potassium) carbonates as a tracer of flooding. We present a novel analytical approach —based on the combination of cross-sectional energy-dispersive X-ray (EDX) mapping and inductively coupled plasma mass spectrometry (ICP–MS) analysis— that can not only visualise, but can also quantitatively describe the electrolysis time dependent flooding in GDEs, leading to a better understanding of electrolyser malfunctions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Propene oxidation and ammoxidation are both initiated by C H bond activation. • Mo O bonds interacting with Bi cations are the active centers for C H activation. • Bi3+ cations adsorb both propene and ammonia for propene ammoxidation. • Allyl amine is a critical intermediate in the formation of acrylonitrile. • The activation energy for formation of allyl amine is lower than to acrolein. Robert K. Grasselli was a pioneer in the development and commercialization of catalysts for propene oxidation to acrolein and ammoxidation to acrylonitrile, products that today are produced at the level of over 10 billion pounds per year. The catalysts used for both processes are contain bismuth molybdates augmented by up to seven additional elements used to attain high activity, selectivity, and stability. The importance of propene oxidation and ammoxidation has stimulated considerable interest in understanding the mechanism and kinetics of these processes and the particular role of catalyst composition and structure in defining catalyst activity and selectivity. Virtually all of this work has been carried out using bismuth molybdates, primarily α-Bi 2 Mo 3 O 12. The objective of this paper is to review the findings of experimental studies and illustrate how theoretical studies based on density functional theory provide additional insights that support deductions drawn from experiments and, more importantly, provide information that cannot be accessed experimentally. [ABSTRACT FROM AUTHOR]

The developed simple mesoporous Ar-G-CM/SiO 2 composite with multiple hydrogen bond donor groups presented good to excellent catalytic activity to the CO 2 cycloaddition with various epoxides under metal-absent and solvent-free conditions. [Display omitted] • TAr-G-CM/SiO 2 catalyst presented efficient catalysis for CO 2 cycloaddition. • The efficient catalysis was originated from HBD groups and mesoporous structure. • The synthesis for catalyst was a green route without toxic solvent use. In this paper, a novel arginine-glucose derived carbonaceous-material-loaded SiO 2 composite catalyst (Ar-G-CM/SiO 2) was synthesized from non-toxic and harmless reagents (arginine, glucose and tetraethylorthosilicate) by simple hydrothermal process. Mesoporous SiO 2 with high specific area served as support for carbonaceous material and provided extra hydrogen bond donor (HBD) groups. Ar-G-CM/SiO 2 with acid-base dual functional groups (COOH, NH 2) and HBD group (OH) presented 62% yield and 99% selectivity to product of propylene carbonate in CO 2 cycloaddition reaction with propylene oxide even at 40 °C, 2 MPa under metal-absent and solvent-free conditions. For some less active epoxides with steric hindrance, Ar-G-CM/SiO 2 also showed good yield and selectivity over 90% by raising temperature to 120 °C. Furthermore, the Ar-G-CM/SiO 2 catalyst could be reused for six successive cycles without significant decrease in catalytic activity or structural deterioration, because the carbon deposition was restrained owing to the mesoporous structure of the catalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • The surface properties CeO 2 with different exposed facets were investigated. • CeO 2 surface lattice oxygen were found important for Pt sintering-resistance. • The effects of ageing and reduction conditions on activities were elucidated. Propane (C 3 H 8) is one of the gases hardest to convert in vehicles' exhausts, which largely affects the emission control ability of after-treatment systems. In this paper, we take Pt-CeO 2 catalysts as an example to investigate the supports' facet-depended propane oxidation performance. Four types of CeO 2 materials with different morphologies (nano-lamella, nano-cube, nano-polyhedron and nano-rod) were synthesized and were found to expose different dominating facets. Consequently, the nano-lamellar CeO 2 , mainly exposed (1 1 0) facet, delivered the best catalytic activity among various Pt-CeO 2 catalysts. The ageing and reduction pretreatments tuned the amount of oxygen vacancies and Pt size/Pt charge which remarkably affected the performances of Pt-CeO 2 catalysts. Based on the experiments and DFT calculations, it was concluded that oxygen on CeO 2 (1 0 0) surface was easily removed in reduction atmosphere leading to electron-rich Pt formed on oxygen absent (1 0 0) surface, while on CeO 2 (1 1 0) surface abundant oxygen vacancies were generated during reduction pretreatment and additional surface lattice oxygen contributed to form electron-deficient Pt kept in small cluster size. This research will help us to develop more efficient exhaust catalysts through a deep understanding of the electronic interactions between the metal and active surface of supports. [ABSTRACT FROM AUTHOR]

[Display omitted] In this paper, sulfated ZrO 2 were synthesized via precipitation and impregnation method, and the promoting effects of support sulfation on selective catalytic reduction (SCR) performance of CeO 2 /ZrO 2 catalysts were investigated. The results revealed that sulfated ZrO 2 could significantly enhance the SCR activity of CeO 2 /ZrO 2 catalysts in a wide temperature range. Especially when S/Zr molar ratio was 0.1, CeO 2 /ZrO 2 -0.1S catalyst exhibited a large operating temperature window of 251 ∼ 500 °C and its N 2 selectivity was 100 % in the temperature range of 150 ∼ 500 °C. Moreover, CeO 2 /ZrO 2 -0.1S catalyst possessed a superior low-temperature activity over 0.1S-CeO 2 /ZrO 2 catalyst. After exposing to 100 ppm SO 2 for 15 h, a high NO conversion efficiency of CeO 2 /ZrO 2 -0.1S catalyst (90.7 %) could still be reached. The characterization results indicated that ZrO 2 treated with a proper dosage of sulfate acid was beneficial to enlarge the specific surface area greatly. Sulfated ZrO 2 was also in favor of promoting the transformation of CeO 2 from crystalline state to highly-dispersed amorphous state, and inhibiting the transformation of ZrO 2 from tetragonal to monoclinic phase. It could also enhance the total surface acidity greatly with an increase in both Brønsted acid sites and Lewis acid sites, thus significantly improving NH 3 adsorption on catalyst surface. Besides, the promoting effect of support sulfation on SCR performance of CeO 2 /ZrO 2 catalysts was also related with the enhanced redox property, higher Ce3+/(Ce3++Ce4+) ratio and abundant surface chemisorbed labile oxygen. The in-situ DRIFTS results implied that nitrate species coordinated on the surface of CeO 2 /ZrO 2 -0.1S catalyst could participate in the Selective catalytic reduction with ammonia (NH 3 -SCR) reactions at either medium or high temperature, suggesting that both Eley-Rideal (E-R) and Langmuir-Hinshelwood (L-H) mechanisms might be followed in SCR reactions. [ABSTRACT FROM AUTHOR]

Nanofirework-like PtRu alloy catalyst has been successfully synthesized and used as an efficient anodic catalyst for glycerol oxidation reaction (GOR) in alkaline medium. [Display omitted] • A class of firework-like bimetallic PtRu alloy nanocatalysts has been successfully fabricated. • The addition of Ru can effectively tune the electronic structure of Pt and greatly improve the performance of the catalyst. • The electrocatalytic properties of bimetallic PtRu catalysts strongly rely on their chemical composition. Electro-oxidation of glycerol is a key anodic reaction in direct alcohol fuel cell (DAFCs). Exploring the cost-effective nanocatalysts for glycerol oxidation reaction (GOR) is very important for the development of DAFC, but it is still challenging. In this paper, nanofirework-like PtRu alloy catalyst was successfully synthesized and used for GOR in alkaline medium. Thanks to the unique nanofirework-like structure and synergetic effects, the activity and stability of the as-prepared PtRu alloy nanofireworks (NFs) toward GOR were significantly improved relative to Pt NFs. In particular, the peak current density of GOR catalyzed by the optimized Pt 1 Ru 3 NFs catalyst reached 2412.0 mA mg−1, surpassing that of commercial Pt/C catalyst. This work has important guidance for the design of advanced anode electrocatalysts for fuel cells. [ABSTRACT FROM AUTHOR]

[Display omitted] • Generalized two-step reaction schemes for studying chemical kinetics on catalyst surfaces. • Analytical expressions derived for surface coverages, reaction rates and degree of rate control for associative and dissociative reaction mechanisms. • Analytical expression derived for determining surface properties of optimal catalysts. • Application of generalized two-step reaction schemes in understanding response of a catalyst surface to transient reaction conditions. Chemical reaction kinetics for steady-state catalytic reactions on heterogeneous catalysts are generally governed by a limited number of elementary steps and the nature of these steps is controlled by the degree of rate control and the surface coverage of reaction intermediates. The generalized two-step reaction scheme, first proposed by Michel Boudart, is used in this paper to drive analytical expressions for the surface coverages by the Most Abundant Reactive Intermediate (MARI); the surface coverage by the Most Abundant Surface Intermediate (MASI); the fraction of the free surface; the degree of rate control for each kinetically significant step; and the overall reaction rate. The two most ubiquitous reaction mechanisms in heterogeneous catalysis, i.e., the associative reaction mechanism and the dissociative reaction mechanism are studied. The applicability of the derived expressions is demonstrated by two case studies: acetone hydrogenation for the associative case and ammonia synthesis for the dissociative case. Scaling relations and BEP correlation are incorporated in the generalized two-step reaction scheme to determine the surface properties of the optimal catalyst. Acetone hydrogenation is used as a case study to demonstrate the applicability of the derived expressions for optimal catalyst. Finally, the application of generalized two-step reaction schemes in understanding the response of a catalyst surface to transient reaction conditions is discussed. Transient reaction kinetics of acetone hydrogenation is used as a case study to demonstrate the applicability of the generalized two-step reaction approach. [ABSTRACT FROM AUTHOR]

The development of highly efficient and low-cost bifunctional electrocatalysts for hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) is the key to the industrialization of large-scale hydrogen production, while the development of non-precious-metal catalysts that can be substituted for precious-metal materials is the current trend of research. In this paper, nickel foam (NF) self-supported CoFe layered bimetallic hydroxide (LDH)-CuCo 2 S 4 electrocatalysts were prepared using a simple hydrothermal and electrodeposition method. The prepared CuCo 2 S 4 @CoFe-LDH/NF catalysts showed good performance in alkaline water oxidation, proton reduction and overall water decomposition with an overpotential of 293 mV for the oxygen evolution reaction (OER) at a current density of 50 mA cm−2 and 63 mV for the hydrogen evolution reaction (HER) at a current density of 10 mA cm−2. When CuCo 2 S 4 @CoFe-LDH/NF was used as a bifunctional electrocatalyst for the decomposition of water, the voltage of the 10 mA cm−2 electrolyzer was only 1.54 V, and the stability of the electrolyzer reached 60 h, which was superior to other bifunctional catalysts. [Display omitted] • CoCu-LDH grows firmly on nickel foam by a hydrothermal method. • Vulcanization at room temperature makes the experimental conditions milder and simpler. • An electrodeposition method was used to grow nanosheets on nanowires. [ABSTRACT FROM AUTHOR]

The irreplaceable silicone materials among the high-tech industry is dimethyldichlorosilane, a monomer whose by-products generated in the synthesis step can be recycled through disproportionation reactions. In this paper, the catalytic activities of NH 2 -MIL-53(Al)@γ-Al 2 O 3 with Brønsted acid active sites and AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3 core-shell catalysts with Lewis acid active sites were investigated and compared for the disproportionation to prepare dimethyldichlorosilane by means of the M06-2X/Def2-TZVP hybrid functional method. The results given for structure, energy, vibrational frequency, IRC values, bond order, ELF and LOL analysis were matched. The results showed that AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3 core-shell catalyst with Lewis acid was more active. Simulated synthesis and interatomic correlation parameters (bond length/nm and bong angle/o) of NH 2 -MIL-53(Al)@γ-Al 2 O 3 (Cat. ,active site No.1-3) and AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3 (Cat.&, Configuration a-d). [Display omitted] • Proposed four- and six-step disproportionation allows recycling of (CH 3) 3 SiCl and CH 3 SiCl 3. • Loading of AlCl 3 presents Lewis catalytic centers, which possess enhanced catalytic activity compared to Brønsted acid. • Optimization of MOFs-based catalysts with core-shell structure, NH 2 -MIL-53(Al)@γ-Al 2 O 3 and AlCl 3 /NH 2 -MIL-53(Al)@γ-Al 2 O 3. [ABSTRACT FROM AUTHOR]

[Display omitted] • Atomically dispersed Ru/Mg-CeO 2 catalyst was prepared and possessed excellent catalytic performance for photo-thermal catalytic CO 2 methanation reaction. • The photo-electron excitation/migration path and the surface structure changes induced by light were systematically characterized by operando experiments. • All potential micro-reaction steps and light intensification steps were determined by in situ DRIFTs experiments. • The reversible dynamic structural evolution between Ru-O-Ce structure and Ru-O v -Ce structure could be induced by light. It is a promising green technology to reduce CO 2 to CH 4 by using renewable solar energy driving photo-thermal catalysis route. However, the efficiency of photo-thermal catalytic CO2 methanation remained to be improved, and the mechanism of this reaction still required further investigation. In this paper, a Ru/Mg-CeO 2 catalyst was designed based on the concepts of single atom catalyst and photo-thermal catalysis concept. The catalyst achieved the CH 4 formation rate of 469 mmol·gcat−1·h−1 at 400 °C under photo-thermal conditions with good catalytic stability. Besides, the superiority of the single-atom of Ru, Ru-O-Ce structure and doping of alkaline metals in catalytic process was proved by a series of physicochemical and optical characterization, and electron migration direction from Ce and Mg elements to Ru sites through Ru-O-Ce and Ru-O-Mg path under photo-thermal catalysis was determined by ISI-XPS experiment. Finally, the comprehensive reaction mechanism and reversible dynamic structural evolution process between Ru-O-Ce and Ru-O v -Ce structures were investigated by in situ DRIFTs experiments, and the source of the excellent performance and structure-function relationship of the catalyst was explored, which provided the theoretical and practical basis for the development of catalyst and industrial application of the reaction. [ABSTRACT FROM AUTHOR]

Platinum group metals (PGMs), especially platinum (Pt), palladium (Pd), and rhodium (Rh), are widely used in automotive three-way catalysts (TWCs). PGM resources are scarce and unevenly distributed, with global reserves of 69,000 t in 2020, of which more than 99% are concentrated in South Africa, Russia, Zambia, and the United States. However, the demand for PGMs worldwide is growing continually, especially in China. The recovery of PGMs from spent TWCs not only can alleviate the contradiction between supply and demand but also have good economic and environmental benefits. This paper briefly analyzes the market demand for Pt, Pd, and Rh in the global automotive industry in recent years, emphasizing the importance of waste TWC recycling. It also presents the current status of waste TWC management in some countries, especially China, and critically reviews the main recycling strategies for waste TWCs. On this basis, suggestions for strengthening the management of waste TWCs in China are put forward, and the future development trend of recycling technology is foreseen. The purpose of this paper is to provide some valuable references for the decision-makers of waste TWC management, and hopefully to provide inspiration for related scholars on the future research direction of waste TWC recycling technology. [Display omitted] • The management regulations of waste TWCs in some countries, especially in China, was introduced. • The research progress of the main methods of PGMs recovery was critically reviewed. • Some management suggestions of waste TWCs and the future development trend of recycling technology are put forward. [ABSTRACT FROM AUTHOR]

Biomass valorization via catalytic gasification is a potential technology for commercizalization to industrial scale. However, the generated tar during biomass valorization posing numerous problems to the overall reaction process. Thus, catalytic tar removal via reforming, cracking and allied processes was among the priority areas to researchers in the recent decades. This paper reports new updates on the areas of catalyst development for tar reduction. The catalyst survey include metallic and metal-promoted materials, nano-structured systems, mesoporous supports like zeolites and oxides, group IA and IIA compounds and natural catalysts based on dolomite, palygorskite, olivine, ilmenite, goethite and their modified derivatives. The influence of catalyst properties and parameters such as reaction conditions, catalyst preparation procedures and feedstock nature on the overall activity/selectivity/stability properties were simultaneously discussed. This paper not only cover to model compounds, but also explore to real biomass-derived tar for consistency. The area that require further investigation was identified in the last part of this review. [Display omitted] • Catalytic biomass gasification is a promising technology in recent times. • Tar production is a great challenge associated with the process upgrade. • Different pure/modified catalysts are employed as tar reduction systems. • Recent literature details on these catalysts and allied parameters reviewed. • Mechanisms of actions and ways forward highlighted for research benefits. [ABSTRACT FROM AUTHOR]

Energy security and waste management are gaining global attention. The modern world is producing a large amount of liquid and solid waste as a result of the increasing population and industrialization. A circular economy encourages the conversion of waste to energy and other value-added products. Waste processing requires a sustainable route for a healthy society and clean environment. One of the emerging solutions for waste treatment is plasma technology. It converts waste into syngas, oil, and char/slag depending on the thermal/non-thermal processes. Most of all the types of carbonaceous wastes can be treated by plasma processes. The addition of a catalyst to the plasma process is a developing field as plasma processes are energy intensive. This paper covers the detailed concept of plasma and catalysis. It comprises various types of plasma (non-thermal and thermal) and catalysts (zeolites, oxides, and salts) which have been used for waste treatment. Catalyst addition improves gas yield and hydrogen selectivity at moderate temperatures. Depending on the properties of the catalyst and type of plasma, comprehensive points are listed for the selection of the right catalyst for a plasma process. This review offers an in-depth analysis of the research in the field of waste-to-energy using plasma-catalytic processes. [Display omitted] • Sustainable approach towards waste valorization is highly imperative worldwide. • Synergistic effect of various catalysts and plasma has been reported. • Catalyst plasma technology gives up to 68% gas yield at 500 °C temperature. • This technology appears to be considerable alternative for waste conversion. • Limited information is available in literature on catalytic thermal plasma system. [ABSTRACT FROM AUTHOR]

Various catalysts are being used in fuel production from biomass and polymeric waste for the obtention of an alternative energy source with both environmental friendliness and economic viability. Biochar, red mud bentonite, and calcium oxide have been shown to play a pertinent role as catalysts in waste-to-fuel conversion processes, such as transesterification and pyrolysis. In this line of thought, this paper has provided a compendium of the fabrication and modification technologies of bentonite, red mud calcium oxide, and biochar, together with their various performances in their application in the waste-to-fuel processes. Additionally, an overview of the structural and chemical attributes of these components is discussed regarding their efficiency. Ultimately, research trends and future points of focus are evaluated, and it is observed that techno-economic optimization of catalyst synthetic routes and investigation of new catalytic formulations, such as biochar and red mud-based nanocatalysts, are potential prospects. This report also offers future research directions that are anticipated to contribute to the development of sustainable green fuel generation systems. [ABSTRACT FROM AUTHOR]

Platinum catalysts derived from MOF have shown excellent potential in oxygen reduction reaction (ORR) of fuel cells. In this paper, we applied a simple and efficient synthesis method to prepare ZIF-67-R x (x ​= ​0–4) with different sizes. Co@MOF-R x (x ​= ​0–4) skeleton supports with carbon nanotube structure were obtained by further pyrolysis. Pt/Co@MOF-R x (x ​= ​0–4) catalysts were synthesized by loading Co@MOF-R x with 10% Pt. By changing the content of metal precursor, the nanometer size of ZIF-67-Rx was reduced from 722 ​nm to 93 ​nm. Pt/Co@MOF-R x showed super high oxygen reduction activity and superior cycle stability. At 0.9 ​V, the mass activity(MA) and specific activity(SA) were 9.63 ​mA mg Pt −1and 1.33 ​mA ​cm2, respectively, which were 1.54 and 1.23 times higher than those of Pt/C(20%). After 6000 cycles, it shows excellent stability than Pt/C(20%). This work brings new opportunities to design and prepare promising catalyst supports for proton exchange membrane fuel cells. [Display omitted] • ZIF-67 with different sizes was prepared, and its nano size decreased from 722 ​nm to 93nm. • Co and Pt are used as active sites in Pt/Co@MOF-R2, respectively. • Pt/Co@MOF-R 2 exhibited ultra-high oxygen reduction activity, and its mass activity (@0.9 ​V) and specific activity (@0.9 ​V) were 1.54 and 1.23 times that of Pt/C (20%). [ABSTRACT FROM AUTHOR]

In this study, the melamine (Mel) modification method was adopted to optimize the NH 3 -SCR activity of Ce 20 W 10 Ti 100 O z doped with C or/and N elements. It was found that with the improved doping of C or/and N into the lattice of anatase TiO 2 of Ce 20 W 10 Ti 100 O z , the dispersion of tungsten/cerium species and the conversion of partial Ce4+ to Ce3+ on its surface were signicantly enhanced, resulting in a large improvement of its surface chemical adsorbed oxygen(O α) concentration. Interestingly, the enhancement of Mel/Ti(SO 4) 2 mass ratio slightly decreases the surface N/O α concentrations, but further improves the surface Ti concentration and Ce3+/(Ce3++Ce4+) molar ratio. Furthermore, Mel modification increases the surface/sub-surface oxygen relative concentrations of Ce 20 W 10 Ti 100 O z , although decreases its low-temperature reducibility and acidity. Due to the larger N doped amount, Ce 20 W 10 Ti 100 O z -Mel t :Ti ​= ​1:2 shows higher surface acidity and O α /(O α +O β) molar ratio than Ce 20 W 10 Ti 100 O z -Mel t :Ti ​= ​4:2, which might be responsible for its improved catalytic performance due to the melamine (Mel) modification. In this paper, melamine (Mel), the nitrogen and carbon-rich material, was firstly used to modify Ce 20 W 10 Ti 100 O z catalyst via the hydrothermal co-precipitation method to promote the NH 3 -SCR activity. [Display omitted] • C/N elements were doped to improve the NH 3 -SCR activity of Ce 20 W 10 Ti 100 O z via Mel modification. • The effect of Mel modification on the physicochemical properties of the catalyst was revealed. • Regulating the relative doping of C or/and N to affect the activity of the catalyst. [ABSTRACT FROM AUTHOR]

Current energy systems have a significant environmental impact and contribute to the climate change. The future energy systems must call upon clean and renewable sources, capable of producing energy with low CO 2 emission, hence partly decarbonizing the energy sector. Producing H 2 by catalytic steam reforming of methanol (CSRM) is gaining interest for its specific applications in fuel cells, in a decentralized H 2 production, or to locally boost the heat content of e.g. natural gas. Supported metal catalysts enhance the endothermic steam-driven methanol conversion. The paper discusses the CSRM manufactures and assesses 2 novel, cheap and efficient catalysts (Co/α-Al 2 O 3 and MnFe 2 O 4). The performance of the Co/α-Al 2 O 3 catalyst is significantly superior to MnFe 2 O 4. The methanol conversion exceeds 95% with high H 2 yields (>2.5 mol H 2 /mol CH 3 OH) and low CO and CO 2 by-product formation. The methanol reaction is very fast and a nearly constant product distribution is achieved for gas-catalyst contact times in excess of 0.3 s. The catalyst maintains its efficiency and selectivity for several days of reaction. The hydrogen productivity of the Co/α-Al 2 O 3 is about 0.9 L H 2 g cat −1 h−1., nearly a fourfold of the MnFe 2 O 4 alternative. The different occurring reactions are combined in a kinetics analysis and demonstrate the high rate of reaction and the predicted product distribution. A catalytic sintered metal fleece reactor is finally developed, mostly in view of its integration with a solid oxide fuel cell (SOFC). The assessed CSRM system clearly merits further pilot plant research. • The catalytic steam reforming of methanol is investigated. • Co/α-Al 2 O 3 and MnFe 2 O 4 were used as catalysts. • The yield is about 2.5 mol H 2 /mol CH 3 OH. CO and CO 2 are by-products. • No catalyst coking is observed. • The reaction rate is very high: complete CH 3 OH conversion is achieved within 0.3 s. [ABSTRACT FROM AUTHOR]

The paper presented facile method for preparing Mn, Co-BTC (BTC ​= ​1,3,5-benzenetricarboxylic acid) derived catalyst with honeycomb structure through direct decomposition of Mn and Co based metal-organic framework (MOF) Mn, Co-BTC in air. Also, the correlation between catalytic performance of MOF (metal organic framework) derivatives for the selective catalytic reduction (SCR) of NO x with ammonia and annealing temperature have been investigated. The catalytic activity test results indicated that annealing temperature had the clear promoting effects on catalytic performance. The X-ray photoelectron spectroscopic (XPS), X-ray diffraction (XRD), Thermogravimetric (TG), Scanning electron microscopy (SEM), Temperature programmed reduction of H 2 (H 2 -TPR) and Fourier-transform infrared (FTIR) spectra were employed to characterize Mn, Co-BTC and its derived catalysts. Based on SEM, FTIR and XRD analytical results, Mn, Co-BTC with nanoneedle structure turned into (Co, Mn) (Co, Mn) 2 O 4 spinel compound with honeycomb structure accompanied by decomposition of organic linkers through direct annealing process. The XPS and H 2 -TPR results showed that Mn, Co-BTC-500 (Mn, Co-BTC annealed at 500 ​°C) had the greatest interaction between Mn and Co, resulting in high catalytic performance for NH 3 -SCR of NO x , which were consistent with catalytic performance test results. Finally, based on the in-situ DRIFT experiments, it was suggested that the SCR process of NO x with NH 3 over Mn, Co-BTC-500 followed both Langmuir–Hinshelwood (L–H) mechanism and Eley-Rideal (E-R) mechanism. Mn, Co-BTC-derived catalyst with honeycomb structure the outstanding synergistic catalytic effect between manganese and cobalt presents good catalytic performance and SO 2 resistant for NH 3 -SCR. [Display omitted] • Among Mn, Co-BTC-derived catalysts, Mn, Co-BTC-500 catalyst had the best catalytic performance. • The main reason for good catalytic performance was due to its honeycomb structure and strong interaction between Mn and Co. • The SCR process of NO x with NH 3 over Mn, Co-BTC-500 followed both Langmuir–Hinshelwood (L–H) mechanism and Eley-Rideal (E-R) mechanism. [ABSTRACT FROM AUTHOR]

Large-volume production of poly(ethylene terephthalate) (PET), especially in the form of bottles and food packaging containers, causes problems with polymer waste management. Waste PET could be recycled thermally, mechanically or chemically and the last method allows to obtain individual monomers, but most often it is carried out in the presence of homogeneous catalysts, that are difficult to separate and reuse. In view of this, this work reports for the first time, application of bimetallic MOF-74 – as heterogeneous catalyst - for depolymerization of PET with high monomer (bishydroxyethyl terephthalate, BHET) recovery. The effect of type and amount of second metal in the MOF-74 (Mg/M) was systematically investigated. The results showed increased activity of MOF-74 (Mg/M) containing Co2+, Zn2+ and Mn2+ as a second metal, while the opposite correlation was observed for Cu2+ and Ni2+. It was found that the highest catalytic activity was demonstrated by the introduction of Mg–Mn into MOF-74 with ratio molar 1:1, which resulted in complete depolymerization of PET and 91.8% BHET yield within 4 h. Furthermore, the obtained catalyst showed good stability in 5 reaction cycles and allowed to achieve high-purity BHET, which was confirmed by HPLC analysis. The as-prepared MOF-74 (Mg/Mn) was easy to separate from the post-reaction mixture, clean and reuse in the next depolymerization reaction. [Display omitted] • MOF-74 (Mg/M) exhibits catalytic activity in PET depolymerization. • Introducing of Co2+, Zn2+ and Mn2+ into MOF-74 (Mg/M) increases catalytic activity. • MOF-74 (Mg/Mn) causes complete depolymerization of PET and 91.8% recovery of BHET. • MOF-74 (Mg/Mn) shows high efficiency and stability over five PET conversion cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] The size of silver nanoparticles (Ag NPs) and loading amount of Ag NPs onto their substrate/carrier are two key factors for their efficient applications. Herein, we present a facile method for in situ synthesizing ultrafine and highly loaded Ag NPs on the surface of tannin-coated catechol-formaldehyde resin (TA-CFR) nanospheres. TA-CFR nanospheres act as green and highly efficient reducing agents for converting silver ions (Ag+) into Ag NPs, and the size of resultant Ag NPs is only ∼ 7.5 nm, and the Ag NPs loading capacity of TA-CFR is as high as 61.5 wt%, both of which contribute to the very high specific surface area of Ag NPs. Consequently, the as-synthesized TA-CFR@Ag composites show high catalytic performance, and the catalytic rate for the reduction of 4-nitrophenol is almost 10 times higher than that of the control. Meanwhile, TA-CFR@Ag composites also possess high antibacterial activity, efficiently inhibiting the growth of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). Furthermore, tannin coating (thickness: ∼ 15 nm) minimizes the aggregation of Ag NPs, and enhances the reusability and stability of resultant Ag NPs, because of their high surface charges (the zeta potential is up to −65.5 ± 1.9 mV) and strong coordination capability with Ag NPs. This work provides a new frontier to develop multifunctional nanomaterials focusing on the green catalyst synthesis and environmental-remedy applications. [ABSTRACT FROM AUTHOR]