Strategies for Electrocatalytic Reduction and Photoelectrochemical Conversion of Carbon Dioxide to Fuels and Utility Chemicals

Abstract

There has been growing recent interest in the development of approaches to effectively sequester, capture or convert carbon dioxide to carbon-based simple organic fuels or utility chemicals. In principle, the low-temperature electrocatalytic and visible-light-induced photoelectrochemical approaches to reduction of CO2 show promise owing to their environmental compatibility and feasibility to combine with renewable energy sources. Electrochemical reductions of CO2 are multi-electron and multi-proton processes with considerable kinetic barriers requiring development of carefully designed electrode materials. Furthermore, when the CO2-reduction is performed in aqueous solutions, the competitive hydrogen evolution reaction is a complicating side-reaction. An additional problem is the appearance of the poisoning or passivating CO-type intermediates. Among important issues are the development of robust specific electrocatalytic systems and stable functionalized semiconducting photocatalytic materials, as well as the understanding of structure - activity relationships. In practical electrolysis cells, the CO2-reduction (at cathode) is accompanied by water oxidation (at anode or photoanode).