Concurrent photocatalytic bicarbonate (aqueous-CO2) reduction and xylose reforming to produce compounds from C—C coupling

Abstract

Using CO2 (or aqueous-CO2, HCO3−) and biomass as feedstock to produce chemicals under solar irradiation represents a promising approach to achieving the net-zero emission goal. In this study, we employed a highly efficient •H-forming photocatalyst to convert HCO3−, demonstrating the occurrence of CC coupling to produce C2-species. Under simulated solar illumination, the photocatalytic system consistently reduces HCO3− into acetate through the coupling of •CO2− radicals. Additionally, in the photoreforming of xylose, acetate emerges as the predominant product, likely resulting from the coupling of •CO2− derived from the interaction of formate and •OH. Notably, a C6-compound is generated through CC coupling of radicals originating from HCO3− and xylose. Achieving an overall apparent quantum efficiency of 26% under 420-nm irradiation, our work underscores the feasibility of concurrently photocatalyzing the conversion of CO2 and biomass into chemicals through CC coupling. This study not only highlights the significance of our approach in contributing to the net-zero emission goal but also emphasizes the novelty of achieving concurrent photocatalytic conversion.