Rational design of bismuth-based catalysts for electrochemical CO2 reduction

Sustainable conversion of carbon dioxide (CO2) to high value-added chemicals and fuels is a promising solution to solve the problem of excessive CO2 emissions and alleviate the shortage of fossil fuels, maintaining the balance of the carbon cycle in nature. The development of catalytic system is of great significance to improve the efficiency and selectivity for electrochemical CO2 conversion. In particular, bismuth (Bi) based catalysts are the most promising candidates, while confronting challenges. This review aims to elucidate the fundamental issues of efficient and stable Bi-based catalysts, constructing a bridge between the category, synthesis approach and electrochemical performance. In this review, the categories of Bi-based catalysts are firstly introduced, such as metals, alloys, single atoms, compounds and composites. Followed by the statement of the reliable and versatile synthetic approaches, the representative optimization strategies, such as morphology manipulation, defect engineering, component and heterostructure regulation, have been highlighted in the discussion, paving in-depth insight upon the design principles, reaction activity, selectivity and stability. Afterward, in situ characterization techniques will be discussed to illustrate the mechanisms of electrochemical CO2 conversion. In the end, the challenges and perspectives are also provided, promoting a systematic understanding in terms of the bottleneck and opportunities in the field of electrochemical CO2 conversion.