Multi-dimensional Pt/Ni(OH)2/nitrogen-doped graphene nanocomposites with low platinum content for methanol oxidation reaction with highly catalytic performance

Abstract

Direct methanol fuel cell has been widely recognized as the ideal renewable energy conversion device. However, it still suffers from two major limitations: the heavy use of precious metal platinum and the sluggish kinetics of methanol oxidation catalytic reaction, which have prevented its large-scale commercialization. Therefore, it is considered desirable to design rational and greatly effective catalysts. In this work, multi-dimensional ternary composite electrocatalysts of Pt/Ni(OH)2/nitrogen-doped graphene catalysts have been synthesized with 0D Pt nanoparticles on the 2D Ni(OH)2 nanosheets supported by 3D porous nitrogen-doped graphene hydrogel, and with a low amount (4.26 wt%) of Pt. Notably, the multi-dimensional porous structure design, abundant hydroxyl species, and mutual interactions of ternary catalysts endow high activity promoting the poisonous CO or CO-like intermediates oxidation and propelling the kinetics of sluggish MOR. These novel Pt/Ni(OH)2/NG catalysts exhibit an excellent mass activity of 2.99 A mg−1Pt for methanol electrooxidation, which is about 2.8 and 4.8 times higher than those of commercial PtRu/C and Pt/C, respectively. Furthermore, both durability and CO tolerance of Pt/Ni(OH)2/NGs electrocatalysts are significantly improved.