Cooperative electrocatalytic effect of Pd and Ce alloys nanoparticles in PdCe@CNWs electrode for oxygen evolution reaction (OER)

Abstract

Electrocatalytic water oxidation is an ecofriendly and intelligent approach for oxygen evolution from water because it requires only water and electrical potential/energy as inputs. However, the oxygen evolution reaction (OER) is the most challenging multi-electron and proton transfer reaction during water electrolysis for hydrogen production. The electrocatalyst is the critical component that controls the efficiency of oxygen evolution. Therefore, it is essential to explore efficient and durable electrocatalysts that must have significant efficiency compared to the benchmark catalyst (i.e., RuO2) for OER. Herein, self-supported carbon nanowires (CNWs) decorated with bimetallic palladium-cerium PdCe alloys nanoparticles (NPs) were synthesized through an electrospinning-thermal carbonation approach to overcome the kinetic barriers and deliver decent alkaline OER activity. As a result, the PdCe/CNWs requires a low overpotential of ∼360 and ∼450 mV vs. RHE to deliver the current density of 10 and 50 mA/cm2 with low Tafel slope (62 mV/dec) for OER, which is even comparable to the benchmark, RuO2 (360 mV and 73 mV/ dec). Notably, only a slight increase (∼ 10 %) in overpotential was observed after 10,000 cycles indicating high electrocatalyst stability. The high stability and improved OER performance of the PdCe/CNWs electrode can be explained by the cooperative catalytic influence between Pd, Ce, and C species.