A series of Pb–Sn catalysts were synthesized via facile chemical reduction for electrocatalytic CO2 reduction (ECR). The optimized sample (Pb7Sn1) achieved 90.53% formate faradaic efficiency (FE) at a potential of −1.9 V vs. Ag/AgCl. Electrochemical and material evaluation reveals that its high performance can be attributed to the rich active sites exposed by the high specific surface area of the electrode. In addition, the synergy between Pb and Sn is also a strong contributor to the high selectivity of formate. This work provides some insights into the preparation of simple and efficient ECR catalysts.