A high-performance Pt–Co bimetallic catalyst with polyethyleneimine decorated graphene oxide as support for hydrolysis of ammonia borane

Abstract

A series of Pt_xCo_1−x bimetallic nanoparticles (NPs) were deposited on polyethyleneimine (PEI) decorated graphene oxide (GO) by a simple co-reduction method. The PEI molecules facilitated the uniform distribution of bimetallic NPs (∼2.3 nm) on GO. PEI–GO/Pt_0.17Co_0.83 showed extraordinary catalytic properties: a total turnover frequency of 377.83 mol_H2 min⁻¹ mol⁻¹_metal, a hydrogen generation rate of 111.28 L_H2 min⁻¹ g⁻¹_metal at 298 K, an activation energy of 51.6 kJ mol⁻¹ and good recyclability (∼80% of the original activity after five cycles). The synergistic effect between Pt and Co, and the small size of these NPs play important roles in improving their catalytic properties. Such low-cost, recyclable bimetallic catalysts will enable many practical applications in portable devices and fuel cells.