Engineering Microenvironments for Photo-Electrochemical Reduction of Carbon Dioxide

Abstract

Due to the escalating crisis of global warming, carbon dioxide (CO2) conversion has garnered significant attention as a pivotal technology for sustainable energy and chemical processes. However, the challenge lies in its nature as a strong endothermic reaction with substantial activation energy, thus requiring extensive energy input. Therefore, integration with renewable energy sources becomes imperative. In this regard, Photo- and electrochemical CO2 reduction (CO2R) presents promising avenues for converting CO2 with water (H2O) using electricity derived from renewable sources, thereby producing various chemicals and fuels. However, the abundance of H2O in the catalytic microenvironment promotes the competing evolution of hydrogen (H2), leading to diminished energy efficiency and selectivity toward CO2R products. Additionally, another challenge is to selectively produce valuable multicarbon products (C2+ products), including C2H4, C2H5OH, and C3H7OH, which hold higher market value and greater market volume compared to single-carbon products (C1 products) like HCOOH, CO, and CH4. Among various CO2R catalysts, Copper (Cu)-based materials have emerged as prominent candidates due to their capability to yield C2+ products with considerable activity and selectivity. Recent studies suggest that catalytic microenvironments significantly influence C2+ production on Cu-based catalysts. Hence, this presentation aims to elucidate the impact of these microenvironments near Cu catalysts and explore how this knowledge can be effectively applied to design a photocathode for the photo-electrochemical reduction of CO2, thereby enhancing the production of C2+ products.