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Single-atom catalysts provide efficiently utilized active sites to improve catalytic activities while improving the stability and enhancing the activities to the level of their bulk metallic counterparts are grand challenges. Herein, we demonstrate a family of single-atom catalysts with different interaction types by confining metal single atoms into the van der Waals gap of two-dimensional SnS2. The relatively weak bonding between the noble metal single atoms and the host endows the single atoms with more intrinsic catalytic activity compared to the ones with strong chemical bonding, while the protection offered by the layered material leads to ultrahigh stability compared to the physically adsorbed single-atom catalysts on the surface. Specifically, the trace Pt-intercalated SnS2 catalyst has superior long-term durability and comparable performance to that of commercial 10 wt% Pt/C catalyst in hydrogen evolution reaction. This work opens an avenue to explore high-performance intercalated single-atom electrocatalysts within various two-dimensional materials. A family of single-atom catalysts synthesized by intercalating metal single atoms into the van der Waals gap of two-dimensional SnS2 is reported. The materials are applied as hydrogen evolving catalysts with good durability and overpotential. [ABSTRACT FROM AUTHOR]

The development of efficient bifunctional catalysts for oxygen reduction and evolution reactions (ORR and OER) is important in the development of rechargeable metal–O2 (air) batteries. Here, a straightforward synthesis of highly efficient bifunctional OER/ORR catalysts MnNiFe/LIG (M111/LIG and M311/LIG where the numbers reflect the relative molar ratio of Mn, Ni, and Fe species) is presented through a facile re‐lasing method. The MnNiFe/LIG shows promising performance in Li–O2 and Li–air batteries without the presence of a redox mediator. The Li–O2 battery with M311/LIG catalysts is reliably discharged and charged for 150 cycles while the discharge potential slightly increases by 0.24 V. The Li‐breathing air battery with M311/LIG catalyst is stable during 350 cycles while the Li‐breathing air battery with M111/LIG catalyst is stable for ≈300 cycles. The function of the M111/LIG and M311/LIG catalysts in the Li–O2 batteries and the influence of the catalysts on the discharge and decomposition products are also investigated. This study promotes further development in carbon–metal oxide composite cathode catalysts for metal–air batteries and underscores the efficacy of laser‐induced graphene for electrode fabrications. [ABSTRACT FROM AUTHOR]

The emerging non-noble metal two-dimensional (2D) catalyst, such as MoS 2 , for the hydrogen evolution reaction (HER) is known to have an inert basal plane unless being converted to a metastable metallic phase or defect engineered. In order to take advantage of the majority of the material in such layered catalysts, fast screening of 2D catalysts with superior basal plane activity is imperative. A local electrochemical measurement method assisted by the e-beam lithography patterning was developed and applied to quantify the activity of basal planes of different layered transition metal dichalcogenides (TMDs) toward HER. This local measurement offers a robust platform to discover active TMDs fast and precisely. The construction of HER volcano plot leads to the discovery of superior basal plane active group VB metal disulfides, especially 3R-NbS 2. Interestingly, the trends found in the volcano plot imply distinctive differences in the mechanism of TMD catalysts compared to their metal counterparts. The intensive hydrogen evolution reaction in-between the basal planes drives self-nanostructuring in morphology of 3R-NbS 2. The increase in the effective surface area, and decrease in the electron-transfer resistance across the substrate and basal plane interface induced by the self-nanostructuring in turn enhances the HER performance of 3R-NbS 2. The 3R-NbS 2 clearly stands out among non-noble metal catalysts for HER. [ABSTRACT FROM AUTHOR]

Abstract: Graphene-supported Pt and Pt3M (M=Co and Cr) alloy nanoparticles are prepared by ethylene glycol reduction method and characterized with X-ray diffraction and transmission electron microscopy. X-ray diffraction depicted the face-centered cubic structure of Pt in the prepared materials. Electron microscopic images show the high dispersion of metallic nanoparticles on graphene sheets. Electrocatalytic activity and stability of the materials is investigated by rotating-disk electrode voltammetry. Oxygen reduction activity of the Pt3M/graphene is found to be 3–4 times higher than that of Pt/graphene. In addition, Pt3M/graphene electrodes exhibited overpotential 45–70mV lower than that of Pt/graphene. The high catalytic performance of Pt3M alloys is ascribed to the inhibition of formation of (hydr) oxy species on Pt surface by the alloying elements. The fuel cell performance of the catalysts is tested at 353K and 1atm. Maximum power densities of 790, 875, and 985mW/cm2 are observed with graphene-supported Pt, Pt3Co, and Pt3Cr cathodes, respectively. The enhanced electrocatalytic performance of the Pt3M/graphene (M=Co and Cr) compared to that of Pt/graphene makes them a viable alternative to the extant cathodes for energy conversion device applications. [Copyright &y& Elsevier]

• A high yield of C 2+ products achieved in CuO/ZnO/C tandem catalysts. • Phase-separated geometric arrangement facilitated CO transport. • Optimal composition balanced CO generation and dimerization rate. • CO utilization efficiency as the key to increase the C 2+ products yield discussed. The comprehensive application of electrochemical CO 2 conversion to multi-carbon hydrocarbons and oxygenates is limited by the low selectivity and activity of copper-derived catalysts. Here, we report co-precipitated CuO/ZnO/C catalysts directing cascade catalysis to enhance the yield of the C 2+ products. The reduced ZnO nanoparticles supply extra CO to increase the *CO surface coverage on the reduced CuO nanoparticles, which boosts the C C coupling reaction kinetics on the reduced CuO surface. The geometric arrangement and composition of phase-separated CuO and ZnO nanoparticles are two vital factors influencing the CO utilization efficiency. The optimum CuO/ZnO/C catalyst exhibits a maximum Faradic efficiency of 74.0 % for overall C 2+ products and 50.9 % for C 2 H 4 at -0.75 V vs. reversible hydrogen electrode, at which the total current density reaches 367 mA cm−2. [ABSTRACT FROM AUTHOR]

Free-standing graphitic C3N4 nanosheets are prepared by liquid phase exfoliation from graphitic C3N4 powders dispersed in various solvents such as isopropanol, N-methylpyrrolidone, water, ethanol, or acetone (sonication for 10 h). [ABSTRACT FROM AUTHOR]