MnO2 Electrocatalysts Coordinating Alcohol Oxidation for Ultra-Durable Hydrogen and Chemical Productions in Acidic Solutions
MnO2 Electrocatalysts Coordinating Alcohol Oxidation for Ultra-Durable Hydrogen and Chemical Productions in Acidic Solutions
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DOI：
10.1002/anie.202107510
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发表时间：
2021-08-18
影响因子：
16.6
通讯作者：
Shi, Jianlin
中科院分区：
文献类型：
--
作者：
Li, Yan;Wei, Xinfa;Shi, Jianlin
与在碱性介质中的电催化制氢相比，在酸性条件下的电催化制氢对于工业化非常重要，不幸的是，由于缺乏可在强酸性条件下持久使用的地球丰富的、成本有效的和高活性的阳极电催化剂，碱性介质中的电催化制氢仍然具有挑战性。锰氧化物是一种常见的易溶于酸性溶液的非贵金属催化剂，它可以作为一种高效、耐用的阳极电催化剂用于酸性醇类水溶液制氢。特别是在甘油溶液中，在10 mA cm（-2）下需要低至1.36 V（相对于RHE）的电势，这比析氧反应（OER）的电势低270 mV，以将甘油氧化成增值化学品，例如甲酸，而不产生氧气。令人惊讶的是，氧化锰在与甘油氧化偶联的电催化制氢中表现出极高的稳定性，其稳定性超过865小时，而OER的稳定性短于10小时。此外，通过原位拉曼光谱分析和密度泛函理论（DFT）计算，探讨了甘油的加入对电化学耐久性的影响。这项工作表明，酸不稳定的金属氧化物电催化剂可以在某些物质存在下在酸性介质中稳定地用于电化学目的，如制氢。
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(-2), 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.