Construction of Asymmetrical Dual Jahn-Teller Sites for Photocatalytic CO2 Reduction

Abstract

Photocatalytic CO₂ reduction (PCR) expresses great attraction to convert useless greenhouse gas into valuable chemical feedstock. However, the weak interactions between catalytic sites and PCR intermediates constrains the PCR activity and selectivity. Herein, we proposed a new strategy to match the intermediates due to the maximum orbital overlap of catalytic sites and C₁ intermediates by establishing dual Jahn-Teller (J-T) sites, in which, the strongly asymmetric J-T sites can break the nonpolar CO₂ molecules and self-adapt the different structure of C₁ intermediates. Taking cobalt carbonate hydroxide as an example, the weakly symmetric dual cobalt (Co₂ ) dual J-T sites, weakly asymmetric Fe&Co sites and strongly asymmetric Cu&Co sites were assembled. After illumination, the interaction between dual J-T sites and the CO₂ molecules enhances J-T distortion, which further modulates the PCR activity and selectivity. As a result, the Cu&Co sites exhibited CO yield of 8137.9 μmol g^-1 , about 2.3-fold and 4.2-fold higher than that of the Fe&Co and Co₂ sites within 5-hour photoreaction, respectively. In addition, the selectivity achieved as high as 92.62 % than Fe&Co (88.67 %) and Co₂ sites (55.33 %). This work provides a novel design concept for the construction of dual J-T sites to regulate the catalytic activity and selectivity.

Keywords: Cobalt Carbonate Hydroxide; Dual Jahn-Teller Sites; Photocatalytic CO2 Reduction.