Highly dispersive platinum nanoparticles supporting on polyaniline modified three dimensional graphene and catalyzing methanol oxidation

Highlights: • 3D corrugated graphene-based Pt/3D-GNs (PANI) was synthesized by hydrothermal process. • Polyaniline (PANI) was formed in-situ with the aid of catalysis from generated Pt. • Pt particles has better dispersion and stronger interaction with support due to PANI. • Pt/3D-GNs (PANI) exhibits larger active surface area and faster electron transfer. • Pt/3D-GNs (PANI) shows better electrocatalytic performances than Pt/3D-GNs and Pt/C. - Abstract: Direct methanol fuel cells have been attracting serious attention due to its high power density and low pollution, and huge effort has focused on its electrode catalysts. Here, a hydrothermal process was used to synthesize Pt/three dimensional graphene (polyaniline) catalyst (Pt/3D-GNs (PANI)), in which PtCl₄²⁻ and graphene oxide (GO) were reduced synchronously. Especially, aniline was polymerized to form polyaniline (PANI) in situ, catalyzed by pre-generated Pt. After cooling by liquid nitrogen, graphene sheets (GNs) were converted into three dimensional (3D) corrugated graphene. The introduction of PANI promotes formation of 3D graphene structure and favors optimal distribution of Pt particles. Synergistic effect of 3D corrugated graphene structure, highly dispersive Pt nanopartilces and fast electron transfer of support makes Pt/3D-GNs (PANI) have superior electrocatalysis for methanol oxidation. Electrochemical tests show that Pt/3D-GNs (PANI) exhibits much higher electrocatalytic activity (1172 mA mg⁻¹), better stability and improved CO tolerance in comparison with commercial Pt/C.