• Bimetallic catalysts enhance CO2 reduction by tuning electronic structure and creating synergistic active sites, overcoming limitations of single-metal catalysts.
• The review covers both atomically dispersed bimetals on carbon supports and non-atomic bimetals like alloys and heterostructures, detailing synthesis and characterization methods.
• Catalytic mechanisms for different bimetallic systems are proposed, highlighting how secondary metals optimize intermediate binding and reaction pathways.
• Challenges in CO2RR, such as competing hydrogen evolution and product selectivity, are addressed through rational design of bimetallic catalysts.