Three-dimensional porous graphene supported Ni nanoparticles with enhanced catalytic performance for Methanol electrooxidation

Three-dimensional porous graphene (3D-G) is prepared by template-assembly method and employed as catalyst support for Ni nanoparticles for methanol electrooxidation. Morphology characterization confirm that Ni nanoparticles with sizes around 20 nm are uniformly scattered on the pore wall surface of the three-dimensional graphene without apparent agglomeration. Electrochemical measurements indicate that the Ni/3D-G processes higher electrocatalytic activity for methanol oxidation reaction than that of the Ni nanoparticles supported on two-dimensional graphene (Ni/2D-G) and Ni nanoparticles without graphene. The peak current density on Ni/3D-G is 64.6 mA cm^?2, which is 1.5 times higher than that on Ni/2D-G. The remarkable electrocatalytic performance of the Ni/3D-G catalyst are mainly derived from the 3D graphene. As a carrier for methanol oxidation, the 3D-G with abundant pore architecture not only hinder the agglomeration of Ni particles that is beneficial to accelerating the efficient charge transport through the whole catalyst, but also offer readily accessible channels for the diffusion of CH₃OH to the active sites of catalyst surface.