Zhang Qiaoqiao, Guan Jingqi
College of Chemistry, Jilin University, Changchun, 130012, PR China.
ChemSusChem. 2019 Jul 19;12(14):3209-3235. doi: 10.1002/cssc.201900704. Epub 2019 Jun 18.
Water splitting, in which water molecules can be transformed into hydrogen and oxygen, is an appealing energy conversion and transformation strategy to address the environmental and energy crisis. The oxygen evolution reaction (OER) is dynamically slow, which limits energy conversion efficiency during the water-splitting process and requires high-efficiency water oxidation catalysts (WOCs) to overcome the OER energy barrier. It is generally accepted that multinuclear WOCs possess superior OER performances, as demonstrated by the CaMn O cluster in photosystem II (PSII), which can catalyze the OER efficiently with a very low overpotential. Inspired by the CaMn O cluster in PSII, some multinuclear WOCs were synthesized that could catalyze water oxidation. In addition, some mononuclear molecular WOCs also show high water oxidation activity. However, it cannot be excluded that the high activity arises from the formation of dimeric species. Recently, some mononuclear heterogeneous WOCs showed a high water oxidation activity, which testified that mononuclear active sites with suitable coordination surroundings could also catalyze water oxidation efficiently. This Review focuses on recent progress in the development of mono-/multinuclear homo- and heterogeneous catalysts for water oxidation. The active sites and possible catalytic mechanisms for water oxidation on the mono-/multinuclear WOCs are provided.
水分解是指水分子可转化为氢气和氧气的过程，它是一种极具吸引力的能量转换与转化策略，有助于应对环境和能源危机。析氧反应（OER）动力学缓慢，这限制了水分解过程中的能量转换效率，因此需要高效的水氧化催化剂（WOCs）来克服OER能垒。人们普遍认为多核WOCs具有优异的OER性能，如光系统II（PSII）中的CaMn O簇所示，它能够以非常低的过电位高效催化OER。受PSII中CaMn O簇的启发，人们合成了一些能够催化水氧化的多核WOCs。此外，一些单核分子WOCs也表现出较高的水氧化活性。然而，不能排除高活性源于二聚体物种的形成。最近，一些单核非均相WOCs表现出较高的水氧化活性，这证明具有合适配位环境的单核活性位点也能高效催化水氧化。本综述重点介绍了单/多核均相和非均相水氧化催化剂开发的最新进展。文中还介绍了单/多核WOCs上水氧化的活性位点和可能的催化机制。
