锡基材料在自然界含量丰富、价格低廉,在电催化还原CO2制液体燃料反应中具有巨大潜力.但是较低的产物选择性和较差的稳定性限制了其应用.本工作制备的锡量子点电催化剂(Sn-QDs),具有高效、高稳定性和高选择性的电催化还原CO2产HCOOH活性.Sn-QDs的平均颗粒尺寸仅为2～3 nm,结晶性良好.小的颗粒尺寸增大了电化学活性面积(ECSA),Sn-QDs的ECSA约为锡颗粒的4.4倍.ECSA增大以及CO2还原反应动力学加速,促进了CO2电化学转化.在-1.0 V(vs RHE)下,Sn-QDs/CN催化剂的HCOOH法拉第效率(FEHCOOH)达到95％,并且在宽约0.5 V的电势范围内能够保持在83％以上.此外,Sn-QDs/CN可以在24 h内保持良好的电化学稳定性.“,”Sn based materials, as low-cost and earth-abundant electrocatalysts, are potential candidates for CO2 reduction reaction (CO2RR) into liquid fuels. Unfortunately, the low selectivity and stability limits their applications. Herein, we developed an electrocatalyst of Sn quantum dots (Sn-QDs) for efficient, durable and highly selective CO2 reduction to HCOOH. The Sn-QDs were confirmed with high crystallinity and an average size of only 2-3 nm. Small particle size endowed the electrocatalyst with improved electrochemical active surface area (ECSA), which was about 4.4 times of that of Sn particle. This enlarged ECSA as well as accelerated CO2RR kinetics favored the electrochemical conversion of CO2. The Faradaic efficiency of HCOOH (FEHCOOH) on Sn-QDs/CN reached up to 95％ at -1.0 V (vs RHE), which exceeded 83％ in the recorded wide potential window of 0.5 V. Moreover, the Sn-QDs electrocatalyst exhibited good electrochemical durability for 24 h.