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Electrochemically reducing CO2 to valuable fuels or feedstocks is recognized as a promising strategy to simultaneously tackle the crises of fossil fuel shortage and carbon emission. Sn‐based catalysts have been widely studied for electrochemical CO2 reduction reaction (CO2RR) to make formic acid/formate, which unfortunately still suffer from low activity, selectivity and stability. In this work, halogen (F, Cl, Br or I) was introduced into the Sn catalyst by a facile hydrolysis method. The presence of halogen was confirmed by a collection of ex situ and in situ characterizations, which rendered a more positive valence state of Sn in halogen‐incorporated Sn catalyst as compared to unmodified Sn under cathodic potentials in CO2RR and therefore tuned the adsorption strength of the key intermediate (*OCHO) toward formate formation. As a result, the halogen‐incorporated Sn catalyst exhibited greatly enhanced catalytic performance in electrochemical CO2RR to produce formate. [ABSTRACT FROM AUTHOR]

Electrochemical carbon dioxide reduction reaction (CO2RR) refers to the conversion of carbon dioxide into compounds with added value through electrolysis. It is still a great challenge to design and manufacture efficient CO2RR catalysts for desired products. Producing syngas via CO2RR is an environmentally friendly way to reduce CO2 in the atmosphere and the dependence on fossil fuels. Herein, a new class of Cu/In2O3 nanoparticles (NPs) with controlled phases and structures were successfully prepared as superior electrocatalysts for CO2RR, where the CO/H2 ratios in syngas on Cu/In2O3 NPs/C−H2 remained about 1 : 2 at a broad potential range and the total faradaic efficiency of H2 and CO always remained about 90 %. Electronic structural analysis revealed that the excellent performance was attributed to the electronic interaction between amorphous In2O3 and Cu. This work broadens the horizons for designing and preparing fascinating electrocatalysts for CO2RR. [ABSTRACT FROM AUTHOR]

Non‐polar diatomic molecule activation is of great significance for catalysis. Despite the high atomic efficiency, the catalytic performance of single‐atom catalysts is limited by insufficient receiving sites for diatomic molecule adsorption. Here, Fe2 dimers were successfully synthesized through precisely regulating the metal loading on metal‐organic frameworks. The unique role of metal dimers in activating diatomic O2 molecules was explored. In alkaline electrolytes, the specific oxygen reduction reaction activity of Fe2 dimers was 7 times higher than that of Fe1 counterparts. The hydrogen atom transfer probes indicated a different activation mode for O2 on Fe1 and Fe2 dimers, respectively. Theoretical calculation results revealed that Fe2 dimers opened up a new reaction pathway by promoting the direct breaking of O=O bonds, thus avoiding the usual formation of *OOH intermediates, which helped explain the lower H2O2 yield and higher specific activity. [ABSTRACT FROM AUTHOR]

In this study, a facile and effective approach was demonstrated for designing and preparing small Cu nanoparticles (NPs) densely and uniformly distributed on carbon nanofibers (CNFs). Self-supported hybrid CuNPs/CNFs with three-dimensional (3D) architectures were prepared via electrospinning and thermal reduction processes. The hybrid CuNPs/CNFs were directly used as electrodes for an electrocatalytic hydrogen evolution reaction (HER), and they exhibited excellent activity, with a low onset potential of only 61 mV, an overpotential of 200 mV at 10 mA cm −2 , a small Tafel slope (152 mV dec −1 ) and a long-term stability in acidic electrolyte. The 3D self-supported architecture exhibited a high conductivity, a large specific surface area and a high porosity, all of which are beneficial for the access of electrolyte for the CuNPs and the release of the formed H 2 , thereby reducing the overpotentials and accelerating the electrode kinetics. This work demonstrates that CuNPs/CNFs are promising candidates for the substitution of noble metal Pt-based materials in producing the HER from water. [ABSTRACT FROM AUTHOR]