A palladium-doped ceria@carbon core–sheath nanowire network: a promising catalyst support for alcohol electrooxidation reactions

Abstract

A novel palladium-doped ceria and carbon core–sheath nanowire network (Pd–CeO₂@C CSNWN) is synthesized by a template-free and surfactant-free solvothermal process, followed by high temperature carbonization. This hierarchical network serves as a new class of catalyst support to enhance the activity and durability of noble metal catalysts for alcohol oxidation reactions. Its supported Pd nanoparticles, Pd/(Pd–CeO₂@C CSNWN), exhibit >9 fold increase in activity toward the ethanol oxidation over the state-of-the-art Pd/C catalyst, which is the highest among the reported Pd systems. Moreover, stability tests show a virtually unchanged activity after 1000 cycles. The high activity is mainly attributed to the superior oxygen-species releasing capability of Pd-doped CeO₂ nanowires by accelerating the removal of the poisoning intermediate. The unique interconnected one-dimensional core–sheath structure is revealed to facilitate immobilization of the metal catalysts, leading to the improved durability. This core–sheath nanowire network opens up a new strategy for catalyst performance optimization for next-generation fuel cells.