Grain Boundary‐Rich Rh Nanoflowers Grown on 3D Hollow Carbon Sphere‐Intercalated Graphene Nanoarchitectures for Efficient Methanol Oxidation

ABSTRACT Although the direct methanol fuel cell is regarded as a pivotal technology for green energy production and conversion, its commercial scalability is severely hindered by the high cost and inadequate performance of existing Pt‐based catalysts. Herein, we present the rational design and spatial construction of a novel Pt‐alternative catalyst made from grain boundary‐rich Rh nanocrystals with a nanoflower‐shaped morphology grown on hollow carbon sphere‐intercalated 3D reduced graphene oxide (Rh/HCS‐RGO) nanoarchitecture through a controllable assembly strategy. Attributed to its large specific surface area, 3D cross‐linked porous network, numerous Rh grain boundary sites, and good electrical conductivity, the optimized Rh/HCS‐RGO nanoarchitecture exhibits exceptional electrocatalytic methanol oxidation properties in terms of a large electrochemical active surface area of 115.2 m 2 g −1 Rh , a high mass activity of 1232.4 mA mg −1 Rh , and a long service life, which are obviously superior to those of conventional Rh particle catalysts anchored on graphene, hollow carbon spheres, carbon black substrates.