An enhanced electrochemical CO reduction reaction on the SnO-PdO surface of SnPd nanoparticles decorated on N-doped carbon fibers

In the electrocatalytic CO 2 reduction reaction (CO 2 RR), tin-based catalysts are known for their high formate faradaic yield. However higher overpotentials are required to attain a high faradaic yield with high partial current density for formate. Here, we describe the increase in the electrocatalytic CO 2 RR activity of Sn nanoparticles decorated on nitrogen-doped carbon fibers (NCFs) by adding a small amount of Pd. Nitrogen-doped carbon fibers decorated with SnPd nanoparticles (Sn 100− y Pd y -NCF) of different Sn : Pd ratios were synthesized using the electrospinning method and their electrocatalytic CO 2 RR activity was studied. The Sn 100− y Pd y -NCF catalyst with 3 wt% ( y = 3) Pd displayed superior activity for the CO 2 RR and attained a faradaic efficiency of 85%, whereas the NCF with Sn nanoparticles (Sn 100 -NCF) attained only 57% efficiency at the same potential. The surface electronic configuration, Tafel slope (79 mV dec −1 ) and bicarbonate reduction activity of the catalyst reveal that the combination of SnO x -PdO on the catalyst surface is responsible for the superior CO 2 RR activity. Electrochemical reduction of CO 2 to formate on SnPd-NCF. The adsorbed bicarbonate ion promotes the protonation of CO 2 &z.rad; − to HCO 2 − .