Tuning of Ionic Second Coordination Sphere in Evolved Rhenium Catalyst for Efficient Visible‐Light‐Driven CO<sub>2</sub> Reduction
Kaihong Chen, Ning Wang, Zhi‐Wen Yang, Shumei Xia, Liang‐Nian He
Abstract
Abstract Developing an efficient and easy‐to‐handle strategy in designing catalysts for CO 2 reduction into CO by harnessing sunlight is a promising project. Here, a facile strategy was developed to design a Re catalyst modified with an ionic secondary coordination sphere for photoreduction of CO 2 to CO by visible light. By adding ionic liquids or tuning a different ionic secondary coordination sphere, it was discovered that an outstanding optical property, other than CO 2 absorption ability or the ability to dissociation of chloride anion, is the prerequisite for catalyst design. Accordingly, a novel Re catalyst, {Re[BpyMe(tris(2‐hydroxyethyl)amine)](CO) 3 Cl}Br (Re‐THEA), was designed, screened, and resulted in a relative high quantum yield (up to 34 %) for visible‐light‐induced CO 2 reduction with a single‐molecule system. DFT calculations, combined with experimental outcomes, suggested the pendant ionic tris(2‐hydroxyethyl)amino (THEA) group on Re‐THEA can enhance visible‐light absorption, stabilize reaction intermediates, and suppress the Re–Re dimer formation.