Nitrogen-doped graphene aerogel with an open structure assisted by in-situ hydrothermal restructuring of ZIF-8 as excellent Pt catalyst support for methanol electro-oxidation.

Abstract We report an innovative strategy to prepare the porous N-doped graphene aerogel with an open structure and abundant defects by hydrothermal self-assembly of zeolitic imidazolate framework (ZIF)-8 and graphene oxide. The in-situ hydrothermal restructuring of ZIF-8 on graphene sheets plays a key role in the synthesis of the open structure and the uniform N-doping. The dissolution and restructuring of ZIF-8 on graphene oxide obviously suppress the stacking and reunion of graphene sheets to obtain the continuous macroporous structure. Moreover, the introduction of N and Zn creates the abundant N-doped sites and microporous structure. Its unique structure and composition improve the accessible surface area, the mass transfer diffusion, the dispersion and electronic structure of Pt nanoparticles, further resulting in the high catalytic performance of Pt-based catalyst for methanol oxidation reaction (MOR). Its MOR activity is about 1.8 times of commercial Pt/C, and its long cycling durability is improved by about 18.7% compared with commercial Pt/C. This work renders a promising method by utilizing ZIF-8 derivatives to synthesize the excellent N-doped carbon materials for electrochemical applications. Graphical abstract This is the first time to utilize the in-situ hydrothermal restructuring of ZIF-8 to synthesize the N-doped graphene aerogel with a more open structure as excellent Pt catalyst support for methanol electro-oxidation. Image 1 Highlights • In-situ hydrothermal restructuring of ZIF-8 is utilized to prepare the N-doped graphene aerogel. • The as-prepared support possesses a very open structure constructed and abundant defects. • The unique structure improves the accessible surface area, mass transfer diffusion, the Pt dispersion. • Compared with Pt/C, the catalytic activity and durability of methanol oxidation has been increased. [ABSTRACT FROM AUTHOR]