Li Yan, Wei Xinfa, Han Shuhe, Chen Lisong, Shi Jianlin
Shanghai Key Laboratory of Green Chemistry and Chemical Processes, School of Chemistry and Molecular Engineering, East China Normal University, Shanghai, 200062, P. R. China.
Department of Chemistry, Institute of Molecular Plus, School of Science, Tianjin University, Tianjin, 300072, China.
Angew Chem Int Ed Engl. 2021 Sep 20;60(39):21464-21472. doi: 10.1002/anie.202107510. Epub 2021 Aug 18.
Electrocatalytic hydrogen production under acidic conditions is of great importance for industrialization in comparison to that in alkaline media, which, unfortunately, still remains challenging due to the lack of earth-abundant, cost-effective and highly active anodic electrocatalysts that can be used durably under strongly acidic conditions. Here we report an unexpected finding that manganese oxide, a kind of common non-noble catalysts easily soluble in acidic solutions, can be applied as a highly efficient and extremely durable anodic electrocatalyst for hydrogen production from an acidic aqueous solution of alcohols. Particularly in a glycerol solution, a potential of as low as 1.36 V (vs. RHE) is needed at 10 mA cm , which is 270 mV lower than that of oxygen evolution reaction (OER), to oxidize glycerol into value-added chemicals such as formic acid, without oxygen production. To our surprise, the manganese oxide exhibits extremely high stability for electrocatalytic hydrogen production in coupling with glycerol oxidation for longer than 865 hours compared to shorter than 10 h for OER. Moreover, the effect of the addition of glycerol on the electrochemical durability has been probed via in situ Raman spectroscopic analysis and density functional theory (DFT) calculations. This work demonstrates that acid-unstable metal oxide electrocatalysts can be used robustly in acidic media under the presence of certain substances for electrochemical purposes, such as hydrogen production.
与碱性介质中的电催化产氢相比，酸性条件下的电催化产氢对工业化具有重要意义。不幸的是，由于缺乏在强酸性条件下可持久使用的储量丰富、成本效益高且活性高的阳极电催化剂，酸性条件下的电催化产氢仍然具有挑战性。在此，我们报告了一个意外发现：氧化锰，一种易溶于酸性溶液的常见非贵金属催化剂，可作为一种高效且极其耐用的阳极电催化剂，用于从醇类酸性水溶液中制氢。特别是在甘油溶液中，在10 mA cm²时，仅需低至1.36 V（相对于可逆氢电极）的电位即可将甘油氧化为增值化学品，如甲酸，而不会产生氧气，该电位比析氧反应（OER）的电位低270 mV。令我们惊讶的是，与OER短于10小时相比，氧化锰在与甘油氧化耦合的电催化产氢中表现出极高的稳定性，长达865小时以上。此外，通过原位拉曼光谱分析和密度泛函理论（DFT）计算，探究了添加甘油对电化学耐久性的影响。这项工作表明，在某些物质存在下，酸不稳定的金属氧化物电催化剂可在酸性介质中稳健地用于电化学目的，如制氢。
