Well-dispersed Pt/Nb₂O₅ on zeolitic imidazolate framework derived nitrogen-doped carbon for efficient oxygen reduction reaction

Abstract

Abstract In this work, an advanced hybrid material was constructed by incorporating niobium pentoxide (Nb 2 O 5 ) nanocrystals with nitrogen-doped carbon (NC) derived from ZIF-8 dodecahedrons, serving as a support, referred to as Nb 2 O 5 /NC. Pt nanocrystals were dispersed onto Nb 2 O 5 /NC using a simple impregnation reduction method. The obtained Pt/Nb 2 O 5 /NC electrocatalyst showed high oxygen reduction reaction (ORR) activity due to three-phase mutual contacting structure with well-dispersed Pt and Nb 2 O 5 NPs. In addition, the conductive NC benefits electron transfer, while the induced Nb 2 O 5 can regulate the electronic structure of Pt element and anchor Pt nanocrystals, thereby enhancing the ORR activity and stability. The half-wave potential ( E 1/2 ) for Pt/Nb 2 O 5 /NC is 0.886 V, which is higher than that of Pt/NC ( E 1/2 = 0.826 V). The stability examinations demonstrated that Pt/Nb 2 O 5 /NC exhibited higher electrocatalytic durability than Pt/NC. Our work provides a new direction for synthesis and structural design of precious metal/oxides hybrid electrocatalysts.