Ethanol and Methanol Oxidation Activity of PtPb, PtBi, and PtBi2 Intermetallic Compounds in Alkaline Media

The electrocatalytic activities of a wide range of intermetallic bulk compounds in the ethanol (EtOH) and methanol (MeOH) oxidation reactions in alkaline media have been studied, and the results have been compared to those of pure polycrystalline Pt and Pd electrodes. The PtPb, PtBi, and PtBi2 intermetallic compounds appeared to be the most promising electrocatalysts among all of the examined bulk electrodes. The current densities at −0.2 V (vs. Ag/AgCl KCl satd.) for PtPb, PtBi, and PtBi2 in EtOH were 21.4, 7.73, and 6.03 mA cm−2, respectively. All of the other intermetallic bulk electrodes exhibited current densities less than 2.5 mA cm−2. PtPb had the lowest onset potential of −0.58 V for EtOH oxidation, which was 20–30 mV less than that of pure Pt and Pd. The current densities of PtPb were at least seventeen times larger than those of pure Pt and Pd. PtBi and PtBi2, which have onset potentials of −0.51 and −0.45 V, respectively, for the EtOH oxidation reaction exhibited extremely stable oxidation currents of 4.8 and 3.3 mA cm−2 during the constant-potential electrolysis of EtOH. The same behavior was also observed for the MeOH oxidation with PtPb, PtBi, and PtBi2 intermetallic compounds.