Light-Driven Electrochemical Carbon Dioxide Reduction to Carbon Monoxide and Methane Using Perovskite Photovoltaics

Serkan Esiner,Junke Wang,René A.J Janssen

doi:10.1016/j.xcrp.2020.100058

Abstract

Summary Storing solar energy in chemical bonds is an effective strategy to overcome the intermittency of sunlight as an energy source. Here, we demonstrate unassisted light-driven electrochemical aqueous carbon dioxide reduction to carbon monoxide and methane using p-i-n double-cation lead halide perovskite solar cells in combination with catalytic electrodes for carbon dioxide reduction and water oxidation at near-neutral pH. Three series-connected photovoltaic cells and gold and ruthenium(IV) oxide electrodes provide carbon monoxide with >8% solar-to-carbon monoxide conversion efficiency for 4.5 h. Including concomitant hydrogen formation, the total solar-to-fuel conversion efficiency remains >8.3% for 10 h. Four series-connected cells with copper and ruthenium(IV) oxide electrodes provide methane. The longevity of the copper electrode improves by setting the cell to open circuit for 1 min every 15 min. The solar-to-methane conversion efficiency is close to 2%, and including 3% solar-to-hydrogen conversion efficiency, the solar-to-fuel conversion efficiency is 5% for 8 h.

Highlights

At the Earth’s surface, sunlight is intermittent in time and place
Storing solar energy in chemical bonds is an effective strategy to overcome the intermittency of sunlight as an energy source
The longevity of the copper electrode improves by setting the cell to open circuit for 1 min every 15 min

Summary

Introduction

At the Earth’s surface, sunlight is intermittent in time and place. To use solar energy as a renewable energy source on a large scale, it is important to develop effective storage solutions. Combining photovoltaic with electrochemical conversion to convert solar energy into energetic chemical bonds is an attractive strategy for high-density energy storage. While light-driven water splitting is attractive in terms of energy efficiency and the reversible chemical cycle of hydrogen in formation and combustion, hydrogen suffers from a low volumetric energy density. Light-driven electrochemical conversion of carbon dioxide (CO2) to methane (CH4), ethylene (C2H4), formic acid (HCOOH), or carbon monoxide (CO) contributes to storing renewable energy but it may reduce increasing atmospheric CO2 levels. The energy required for electrochemical reduction of CO2 depends on the target product and is further determined by catalysts, electrolyte, membrane, and dimensions of the electrochemical system. The selectivity of transition metals toward various products is determined by the overpotential for the formation of reaction

Results

Discussion

Conclusion