Cobalt-based tripodal complexes as molecular catalysts for photocatalytic CO reduction.

Construction of artificial photosynthetic systems including CO reduction is a promising pathway to produce carbon-neutral fuels and mitigate the greenhouse effect concurrently. However, the exploitation of earth-abundant catalysts for photocatalytic CO reduction remains a fundamental challenge, which can be assisted by a systematic summary focusing on a specific catalyst family. Cobalt-based complexes featuring tripodal ligands should merit more insightful discussion and summarization, as they are one of the most examined catalyst families for CO photoreduction. In this feature article, the key developments of cobalt-based tripodal complexes as molecular catalysts for light-driven CO reduction are discussed to offer an upcoming perspective, analyzing the present progress in electronic/steric tuning through ligand modification and dinuclear design to achieve a synergistic effect, as well as the bottlenecks for further development.