Recent progress of Bi-based electrocatalysts for electrocatalytic CO2 reduction

To mitigate the excessively accumulated carbon dioxide (CO2) in the atmosphere and tackle the associated environmental concerns, green and effective approaches are necessitated. The electrocatalytic CO2 reduction reaction (CO2RR) using sustainable electricity under benign reaction conditions represents a viable way to produce value-added and profitable chemicals. In this minireview, recent studies regarding unary Bi electrocatalysts and binary BiSn electrocatalysts are symmetrically categorized and reviewed, as they disclose high faradic efficiencies toward the production of formate/formic acid, which has a relatively higher value of up to 0.50 $kg-1 and been widely used in chemical and pharmaceutical industry. Specifically, the preparation methodologies, electrocatalysts morphologies, catalytic performances and corresponding mechanisms are comprehensively presented. The use of solid-state electrolytes showing high economic prospects for directly obtaining high-purity formic acid are highlighted. Finally, the remaining questions and challenges for CO2RR exploitations using Bi-related electrocatalysts are proposed, while perspectives and the corresponding strategies aiming to enhance their entire catalytic functionalities and boost their performance are provided.