Understanding Methanol Electro-Oxidation Pathways on Nd-Based Metal Oxides via DFT and Electrochemical Studies

In this study, we report for the first time the electrochemical performance of Nd-based metal oxides (NdNiO (NNO), NdCuO (NCO), and NdZnO (NZO)) as electrocatalysts for methanol electro-oxidation. Results show that NCO exhibits superior electrocatalytic performance with a low onset potential of 0.97 V versus reversible hydrogen electrode (RHE) and excellent resistance to CO poisoning. Electrochemical impedance spectroscopy (EIS) revealed a low charge transfer resistance (R_ct) of 1.30 Ω, indicating efficient electron transfer kinetics. The calculated mass activity (M_A) of NCO was 1.68 A/mg, surpassing various reported Pt-based catalysts, such as Pt₆₂Ru₃₅/C (0.47 A/mg), Pt₆₂Ru₁₈Ni₂₀-O/C (0.30 A/mg), and comparable to Pt₆₂Ru₁₈Ni₂₀/C (1.91 A/mg). The density functional theory (DFT) calculation shows that NCO facilitates methanol oxidation through the CHO* intermediate, indicating efficient CO oxidation and CO₂ release. The synergy between Cu 3d and O 2p orbitals plays a crucial role in enhancing the electrocatalytic performance. These findings highlight NCO as a promising and durable electrocatalyst in energy conversion technologies.