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The electrochemical water splitting reaction can convert renewable electricity into clean hydrogen fuel. The efficiency of water splitting is limited to a large extent by the sluggish oxygen evolution reaction (OER). Numerous transition metal oxides have been developed as electrocatalysts for the OER in alkaline medium. However, in-depth studies of the stability of these catalysts have rarely been performed. Here we report a systematic investigation of the stability profiles of five archetypical OER catalysts including CoOx, CoFeOx, CoFeNiOx, NiOx, and NiFeOx. We combine measurements of electrochemical activity, electrochemical quartz crystal microbalance (eQCM), inductively coupled plasma optical emission spectrometry (ICP-OES), and electrochemical impedance spectroscopy (EIS). We find that the eQCM analysis gives incorrect information about the mass change during the OER due to a non-ideal response, and confirms that activity is not a valid descriptor of stability. Of the five oxides, CoOx and CoFeOx lose some mass during the initial period of the OER while CoFeNiOx, NiOx, and NiFeOx maintain their mass. However, all five catalysts undergo noticeable compositional changes due to a dynamic exchange of metal ions with the electrolyte solutions. Partial dissolution of CoOx and incorporation of Fe ions are the main processes of this exchange. The dynamic exchange reaches equilibrium after 6 h, and the catalysts are stable afterwards. [ABSTRACT FROM AUTHOR]

Progress in catalysis is driven by society's needs. The development of new electrocatalysts to make renewable and clean fuels from abundant and easily accessible resources is among the most challenging and demanding tasks for today's scientists and engineers. The electrochemical splitting of water into hydrogen and oxygen has been known for over 200 years, but in the last decade and motivated by the perspective of solar hydrogen production, new catalysts made of earth-abundant materials have emerged. Here we present an overview of recent developments in the non-noble metal catalysts for electrochemical hydrogen evolution reaction (HER). Emphasis is given to the nanostructuring of industrially relevant hydrotreating catalysts as potential HER electrocatalysts. The new syntheses and nanostructuring approaches might pave the way for future development of highly efficient catalysts for energy conversion. [ABSTRACT FROM AUTHOR]

MoO2 microparticles act as an active catalyst for the electrochemical reduction of CO2 in organic solvents such as acetonitrile and dimethylformamide. The catalytic activity and product selectivity depend on temperature and water content of the solvent. [ABSTRACT FROM AUTHOR]

An improved synthesis of pincer ligand bis[(2-dimethylamino)phenyl]amine (MeN2NH) was reported. Reaction of the Li complex of MeN2N with suitable Pd, Pt, and Ru precursors gave the corresponding metal complexes. The structures of the Pd, Pt, and Ru complexes were determined. The Ru complex showed activity in catalytic transfer hydrogenation of aryl and alkyl ketones. [ABSTRACT FROM AUTHOR]

MoO2 microparticles act as an active catalyst for the electrochemical reduction of CO2 in organic solvents such as acetonitrile and dimethylformamide. The catalytic activity and product selectivity depend on temperature and water content of the solvent. [ABSTRACT FROM AUTHOR]