Inert Heteroatom Substitution to Modulate Dual-Metal-Sites for Boosting Photoreduction of Diluted CO2

The precise regulation of active sites to steer reaction pathway for photocatalytic CO2 reduction is critical, but remains challenges. Herein, an inert heteroatom substitution strategy is developed to activate adjacent dual-active-sites for boosting photocatalytic reduction of diluted CO2. As a proof of concept, Co2+delta/Ni2+zeta dual-active-sites in layered double hydroxides (LDHs) photocatalyst with high activity is interspaced and regulated by inert Al substitution. The corresponding elementary reaction step is optimized, where the Ni2+zeta site shows high activation of CO2 reduction and weak absorption of *CO, whilst the Co2+delta site facilitates water oxidation. Most importantly, the produced *H on the Co2+delta site is synchronized with the formation of *COOH on the Ni2+zeta site, which synergistically lowers the energy barrier (*CO2 to *COOH) of the rate-determining step. Resulting CoNiAl-LDHs photocatalyst attains nearly 100% selectivity with a production rate of 784 mu mol g(-1) h(-1) toward diluted CO2 reduction to CO, representing the best performance reported to date. This work delivers a feasible strategy via inert site substitution to activate proximate dual sites, which provides fundamental guidance to design photocatalysts for CO2 reduction.