Sinha Soumalya, Williams Caroline K, Jiang Jianbing Jimmy
Department of Chemistry, University of Cincinnati, P.O. Box 210172, Cincinnati, OH 45221, USA.
iScience. 2021 Dec 15;25(1):103628. doi: 10.1016/j.isci.2021.103628. eCollection 2022 Jan 21.
Electrocatalysis is an indispensable technique for small-molecule transformations, which are essential for the sustainability of society. Electrocatalysis utilizes electricity as an energy source for chemical reactions. Hydrogen is considered the "fuel for the future," and designing electrocatalysts for hydrogen production has thus become critical. Furthermore, fuel cells are promising energy solutions that require robust electrocatalysts for key fuel cell reactions such as the interconversion of oxygen to water. Concerns regarding the rising concentration of atmospheric carbon dioxide have prompted the search for CO conversion methods. One promising approach is the electrochemical conversion of CO into commodity chemicals and/or liquid fuels, but such chemistry is highly energy demanding because of the thermodynamic stability of CO. All of the above-mentioned electrocatalytic processes rely on the selective input of multiple protons (H) and electrons (e) to yield the desired products. Biological enzymes evolved in nature to perform such redox catalysis and have inspired the design of catalysts at the molecular and atomic levels. While it is synthetically challenging to mimic the exact biological environment, incorporating functional outer coordination spheres into molecular catalysts has shown promise for advancing multi-H and multi-e electrocatalysis. From this Perspective, herein, catalysts with outer coordination sphere(s) are selected as the inspiration for developing new catalysts, particularly for the reductive conversion of H, O, and CO, which are highly relevant to sustainability. The recent progress in electrocatalysis and opportunities to explore beyond the second coordination sphere are also emphasized.
电催化是小分子转化不可或缺的技术，而小分子转化对社会的可持续发展至关重要。电催化利用电作为化学反应的能源。氢被视为“未来的燃料”，因此设计用于制氢的电催化剂变得至关重要。此外，燃料电池是很有前景的能源解决方案，需要强大的电催化剂来进行关键的燃料电池反应，如氧气与水的相互转化。对大气中二氧化碳浓度不断上升的担忧促使人们寻找二氧化碳转化方法。一种有前景的方法是将二氧化碳电化学转化为商品化学品和/或液体燃料，但由于二氧化碳的热力学稳定性，这种化学过程对能量的需求很高。上述所有电催化过程都依赖于多个质子（H）和电子（e）的选择性输入以产生所需产物。自然界中进化出的生物酶可进行此类氧化还原催化，并在分子和原子水平上启发了催化剂的设计。虽然模拟精确的生物环境在合成上具有挑战性，但将功能性外配位层纳入分子催化剂已显示出推进多质子和多电子电催化的潜力。从这个角度出发，本文选择具有外配位层的催化剂作为开发新催化剂的灵感来源，特别是对于与可持续性高度相关的氢、氧和二氧化碳的还原转化。本文还强调了电催化的最新进展以及探索超越第二配位层的机会。
