Department of Chemistry, Carnegie Mellon University, Pittsburgh, Pennsylvania 15213, USA.
J Am Chem Soc. 2010 Aug 18;132(32):10990-1. doi: 10.1021/ja104766z.
Photolysis of water, a long-studied strategy for storing solar energy, involves two half-reactions: the reduction of protons to dihydrogen and the oxidation of water to dioxygen. Proton reduction is well-understood, with catalysts achieving quantum yields of 34% when driven by visible light. Water oxidation, on the other hand, is much less advanced, typically involving expensive metal centers and rarely working in conjunction with a photochemically powered system. Before further progress can be made in the field of water splitting, significant developments in the catalysis of oxygen evolution are needed. Herein we present an iron-centered tetraamido macrocyclic ligand (Fe-TAML) that efficiently catalyzes the oxidative conversion of water to dioxygen. When the catalyst is combined in unbuffered solution with ceric ammonium nitrate, its turnover frequency exceeds 1.3 s(-1). Real-time UV-vis and oxygen monitoring of the active complex give insights into the reaction and decay kinetics.
水的光解是一种长期研究的太阳能储存策略，涉及两个半反应：质子还原为氢气和水氧化为氧气。质子还原已经得到了很好的理解，当用可见光驱动时，催化剂的量子产率达到 34%。相比之下，水氧化要落后得多，通常涉及昂贵的金属中心，并且很少与光化学动力系统一起工作。在水分解领域取得进一步进展之前，需要在氧气进化催化方面取得重大进展。在此，我们提出了一种基于铁的四氨大环配体（Fe-TAML），它可以有效地催化水氧化为氧气。当催化剂与硝酸铈铵在无缓冲溶液中结合时，其周转率超过 1.3 s(-1)。对活性络合物的实时紫外-可见和氧气监测提供了对反应和衰减动力学的深入了解。
