(Invited) Engineering Microenvironments for Photo-Electrochemical Reduction of Carbon Dioxide

Abstract

Due to the escalating crisis of global warming, carbon dioxide (CO 2 ) 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 CO 2 reduction (CO 2 R) presents promising avenues for converting CO 2 with water (H 2 O) using electricity derived from renewable sources, thereby producing various chemicals and fuels. However, the abundance of H 2 O in the catalytic microenvironment promotes the competing evolution of hydrogen (H 2 ), leading to diminished energy efficiency and selectivity toward CO 2 R products. Additionally, another challenge is to selectively produce valuable multicarbon products (C 2+ products), including C 2 H 4 , C 2 H 5 OH, and C 3 H 7 OH, which hold higher market value and greater market volume compared to single-carbon products (C 1 products) like HCOOH, CO, and CH 4 . Among various CO 2 R catalysts, Copper (Cu)-based materials have emerged as prominent candidates due to their capability to yield C 2+ products with considerable activity and selectivity. Recent studies suggest that catalytic microenvironments significantly influence C 2+ 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 CO 2 , thereby enhancing the production of C 2+ products.