Acidic water electrolysis enables the production of hydrogen for use as a chemical and as a fuel. The acidic environment hinders water electrolysis on non-noble catalysts, a result of the sluggish kinetics associated with the adsorbate evolution mechanism, reliant as it is on four concerted proton-electron transfer steps. Enabling a faster mechanism with non-noble catalysts will help to further advance acidic water electrolysis. Here, we report evidence that doping Ba cations into a Co₃O₄ framework to form Co_3–xBa_xO₄ promotes the oxide path mechanism and simultaneously improves activity in acidic electrolytes. Co_3–xBa_xO₄ catalysts reported herein exhibit an overpotential of 278 mV at 10 mA/cm² in 0.5 M H₂SO₄ electrolyte and are stable over 110 h of continuous water oxidation operation. We find that the incorporation of Ba cations shortens the Co–Co distance and promotes OH adsorption, findings we link to improved water oxidation in acidic electrolyte.

中文翻译：

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掺杂缩短金属/金属距离并促进非贵酸性析氧反应催化剂中的 OH 覆盖

酸性水电解可以生产氢气，用作化学品和燃料。酸性环境阻碍了非贵金属催化剂上的水电解，这是与吸附物演变机制相关的缓慢动力学的结果，依赖于四个协调一致的质子 - 电子转移步骤。使用非贵金属催化剂实现更快的机制将有助于进一步推进酸性水电解。在这里，我们报告了将 Ba 阳离子掺杂到 Co ₃ O ₄骨架中以形成 Co _{3– x} Ba _x O ₄的证据，促进了氧化物路径机制并同时提高了酸性电解质中的活性。Co _{3– x} Ba _x O_{本文报道的4 种}催化剂在 0.5 MH ₂ SO ₄电解质中在 10 mA/cm ²下表现出 278 mV 的过电势，并且在连续水氧化操作的 110 小时内保持稳定。我们发现 Ba 阳离子的掺入缩短了 Co-Co 距离并促进了 OH 吸附，我们发现这些发现与酸性电解质中改善的水氧化有关。