Catalyst design strategies for highly efficient CO2 electroreduction

Abstract

The massive emission of CO₂ has caused significant environmental problems, including global warming, disruption of carbon balance, and threats to human health. Electrocatalytic CO₂ reduction reaction (CO₂RR) that operates under mild conditions to produce small-molecule fuels and value-added chemical products, is viewed as one of the most promising strategies for mitigating atmospheric CO₂ concentrations and restoring the carbon cycle equilibrium. Recent achievements in the development of high-performance electrocatalysts have promoted the practical application of CO₂RR. In this review, the mechanism pathways for forming C₁, C₂, and C₂₊ products, as well as the crucial parameters for evaluating CO₂RR performance are introduced first. Then, the factors affecting CO₂RR performance, such as electrolyzer devices and electrolytes, are also briefly discussed. Most importantly, various strategies that were developed for boosting the performance of electrocatalysts are summarized from the perspective of different products. Furthermore, the effects of these strategies on the active site and the reaction environment are discussed in detail. Finally, the future challenges and perspectives, including design of high-efficient, highly selective and robust CO₂RR electrocatalysts, deeper understanding of structure-performance relationship, insights into the CO₂RR mechanism, and integrating or coupling CO₂RR with other reactions (e.g. N₂ or NO₃⁻ or SO₃^2‐ electroreduction, biomass electrooxidation, etc.) or biological fermentation to produce high-value heteroatom-containing or long-chain organic compounds or improve the overall energy and economy efficiency of CO₂ electrolysis. This review offers valuable insights into methods for developing proper electrocatalysts to steer the reaction pathways toward CO₂RR, and suggests future directions and perspectives on CO₂RR field.