Carbon supported ordered intermetallic Cu₃Sn nanoparticles (NPs), which had a Cu₃Ti type structure (1), was successfully prepared through a wet-chemical method (2) using lithium triethylborohydride as reducing agent. The prepared ordered intermetallic Cu₃Sn was characterized by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and transmission electronic microscope (TEM). Cu₃Sn intermetallic structure not only showed a higher electrocatalytic activity towards CO₂ electrochemical reduction, but also selectively converted CO₂to CO, compared with pure Cu NPs.

Figure 1 allows us to confirm the crystal structure of intermetallic Cu₃Sn, disordered Cu-Sn alloy and pure Cu NPs, respectively. The main diffraction peaks of Cu NPs and disordered Cu-Sn alloy can be observed which are assigned as FCC-type structure while the XRD pattern of intermetallic NPs shows a good fit with stoichiometric Cu₃Sn structure based on Cu₃Ti-type lattice (1). Figure 2 shows the Faradaic efficiency (FE) for gaseous products which was evaluated in CO₂ reduction for intermetallic Cu₃Sn under the potential varying from -0.8 V to -1.6 V vs.RHE. It is suggested that the FE of CO production reaches the highest value of 40 % at -1.4 V, while the FE of hydrogen production is suppressed under 17%.

[1] Y. Watanabe, et al., Acta Cryst., B39, 1983, 306-311.

[2] F. Wang. et al., J. Alloys Comp., 439, 2007, 249–253.