Ethylene glycol oxidation on carbon supported binary PtM (M = Rh, Pd an Ni) electrocatalysts in alkaline media

In this work we prepared binary Pt-based electrocatalysts supported on carbon with a 80:20 (Pt:M) atomic ratio (where M = Rh, Pd and Ni) and tested their activity for the ethylene glycol oxidation reaction (EGOR) in alkaline media. Pt90Pd10/C showed the highest catalytic activity for the EGOR. Then, to estimate the optimum Pd content for the EGOR, a new series of PtPd catalysts within a wide range of compositions was synthesized and tested. The electroactivity is dependent on the composition of PtPd and reaches a maximum at 32 at.% Palladium. In situ FTIR results suggest the presence of Pd increases the production of glycolate, while hinders the formation of carbonate. This inhibition, in turn, seems to be dependent on a previous scission of the molecules. Hence, compositions richer in Pd are more tolerant to surface poisoning because the production of fragments possessing a single carbon atom (such as CO) is hindered over these surfaces.