CeO2 promotes electrocatalytic formic acid oxidation of Pd-based alloys

Engineering metal/oxide interface and controlling composition are the important strategies that aim towards obtaining efficient Pd-based electrocatalysts (ECs). Rationally designed ECs for dehydrogenation of formic acid play a dynamic role in the proper utilization of its chemical energy. Herein, we report Pd3M alloy nanoparticles anchored on CCeO2 (Pd3M/CCeO2, M = Cu, Ni, Co) which shows significant performance towards formic acid oxidation (FAO). Interestingly, Pd3M/CCeO2 (M = Cu, Ni, Co) ECs displayed the best FAO activity via the “dehydrogenation” pathway. The remarkable performance can be mainly attributed to the proper electronic and synergistic effects between Pd and the alloyed metal, which leads to Pd lattice contraction and downshift of d-band center. It was also observed that the FAO activity of Pd3Cu/CCeO2 is superior to that of Pd3Co/CCeO2 and Pd3Ni/CCeO2. The oxygen vacancies in CeO2 and strong Pd/CeO2 interactions established by computational and experimental studies contribute towards the overall electrocatalytic behaviour.