Combination of Organic Dye and Iron for CO2 Reduction with Pentanuclear Fe2Na3 Purpurin Photocatalysts

摘要

Molecular photocatalysts designed with earth-abundant elements are rare and challenging in artificial photosynthesis study. Herein, we report a multimetallic Fe2Na3 purpurin (1) complex for the reduction of CO2 in DMF under visible-light irradiation. The photocatalytic system achieves 91% selectivity and 2625 +/- 334 turnovers of CO in 120 h, which is among the highest reported for a noble-metal-free catalyst without an additional photosensitizer. UV-vis and electrochemical studies suggest that the mechanism involves subsequent reductions and protonations of 1 to generate [(Fe2Na3)-Na-II((PP)-P-(H)2)(6)](5-) and [(Fe2Na3)-Na-III((PP)-P-(H)2)(6)](3-) as the active photocatalysts in CO2 reduction.