Enhanced catalytic activity and stability of Pt nanoparticles by surface coating of nanosized graphene oxide for hydrogen production from hydrolysis of ammonia–borane

Abstract

We report the electronic modification of silica supported Pt nanoparticles (SiO₂@Pt) by coating a 1 nm thin layer of nanosized graphene oxide (NGO). The resulting SiO₂@Pt@NGO showed much enhanced catalytic activity and stability for hydrogen production from hydrolysis of ammonia–borane compared with SiO₂@Pt and graphene supported Pt nanoparticles, with an impressive initial TOF value reaching 324.6 mol_H2 mol_Pt⁻¹ min⁻¹. Detailed characterization by means of HRTEM and EDS elemental mapping proved the structural correctness of SiO₂@Pt@NGO. The XPS results showed that the binding energy of Pt⁰ 4f_7/2 in SiO₂@Pt@NGO was 71.12 eV slightly higher than 70.84 eV of Pt⁰ 4f_7/2 in SiO₂@Pt, indicating more electron-deficient Pt atoms after the interaction with NGO, which may be responsible for the enhanced catalytic performance.