Recent progress in solar-driven CO2 reduction to multicarbon products

Currently, most catalysts used for photoconverting carbon dioxide (CO₂) typically produce C₁ products. Achieving multicarbon (C₂₊) products, which are highly desirable due to their greater energy density and economic potential, still remains a significant challenge. This difficulty is primarily due to the kinetic hurdles associated with the C–C coupling step in the process. Given this, devising diverse strategies to accelerate C–C coupling for generating multicarbon products is requisite. Herein, we first give a classification of catalysts involved in the photoconversion of CO₂ to C₂₊ fuels. We summarize metallic oxides, metallic sulfides, MXenes, and metal–organic frameworks as catalysts for CO₂ photoreduction to C₂₊ products, attributing their efficacy to the inherent dual active sites facilitating C–C coupling. In addition, we survey covalent organic frameworks, carbon nitrides, metal phosphides, and graphene as cocatalysts for CO₂ photoreduction to C₂₊ products, owing to the incorporated dual active sites that induce C–C coupling. In the end, we provide a brief conclusion and an outlook on designing new photocatalysts, understanding the catalytic mechanisms, and considering the practical application requirements for photoconverting CO₂ into multicarbon products.