Photovoltaic-Powered Electrochemical CO<sub>2</sub> Reduction: Benchmarking against the Theoretical Limit
Bingxin Liu, Lushan Ma, Hao Feng, Ying Zhang, Jingjing Duan, Yongjie Wang, Dong Liu, Qiang Li
Abstract
In this work, benchmarking against the theoretical limit and against water splitting was used to indicate the promise of photovoltaic-powered electrochemical CO 2 reduction. A benchmark device was built by the successful integration of high-performance cathode, anode, membrane-electrode-assembly reactor and dual-junction photoabsorber. This is the first report on dual-junction photoabsorber-driven CO 2 electrolysis. We experimentally demonstrated a record-high solar-to-chemical energy conversion efficiency of 21.3% and a projected efficiency of 25.3%. This performance metric remarkably reaches 87% of the theoretical efficiency limit and surpasses the solar-to-hydrogen efficiency based on the same photoabsorber. This work paves the way for efficient solar fuel production with solar CO as the intermediate.