Advanced solar-driven CO2 photothermal–electrocatalytic co-reduction system design and research

Abstract

The efficient reduction of CO₂ is significant for achieving carbon neutrality and renewable fuel synthesis. However, CO₂ thermostatic systems are limited by energy utilization efficiency, while high-temperature electrocatalysis is limited by the need for inlet preheating of the material. Considering the existence of high-grade thermal energy at the outlet of thermostatic CO₂ not utilized, the article proposes a combined thermal–electrocatalytic CO₂ reduction system, which can utilize high-temperature products of thermostatic CO₂ reduction for further electrocatalytic co-electrolysis of H₂O as well as CO₂, and at the same time solves the problems of lower efficiency of thermostatic reduction as well as the need of pre-heating for electrocatalytic reduction. Mathematical models of the two subsystems were developed, and thermodynamic analyses were performed. The results show that the efficiency of the thermostatic reduction part could be optimized by designing the reaction parameters, and the maximum efficiency could reach 25.42%, while the electrolytic efficiency of the electrocatalytic part could reach 99.21%. The electrocatalytic efficiency of the coupled system can be increased by 24.84% to 95.80%. And when the two systems are coupled to catalyze CO₂, the overall efficiency of the system can be increased by 29.00%.