PVP-stabilized platinum nanoparticles supported on modified silica spheres as efficient catalysts for hydrogen generation from hydrolysis of ammonia borane

Ammonia borane (AB) is considered to be a promising solid hydrogen carrier. In this work, poly(N-vinyl-2-pyrrolidone) (PVP)-protected platinum nanoparticles are supported on gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) modified silica spheres (Pt-PVP/SiO2(M)), which are firstly used as highly efficient catalysts for hydrolysis of AB. Platinum nanoparticles possess a tiny size of 2-3 nm and are uniformly dispersed over modified silica spheres. Pt-PVP/SiO2(M) catalysts with a Pt loading amount of 1.30 wt% show the highest catalytic activity with a turnover frequency (TOF) value of 371 mol(H2) mol(Pt)(-1) min(-1) (866 mol(H2) mol(Pt)(-1) min(-1) corrected for the surface atoms) at 25 degrees C. The activation energy is calculated to be 46.2 kJ/mol. Furthermore, owing to the synergistic effect between the modifier of silica spheres and the capping agent of metal nanoparticles, Pt-PVP/SiO2(M) catalysts have a higher loading amount (8.7 and 6.5 times) and TOF value (4.8 and 5.5 times) than the counterparts prepared without gamma-MPS and PVP, respectively. (C) 2021 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.

Automated summary

Poly(N-vinyl-2-pyrrolidone) (PVP)-protected platinum nanoparticles supported on gamma-methacryloxypropyltrimethoxysilane (gamma-MPS) modified silica spheres (Pt-PVP/SiO2(M)) exhibit high catalytic activity for the hydrolysis of ammonia borane (AB), with small size, uniform dispersion, and low activation energy. The synergistic effect between the modifier of silica spheres and the capping agent of metal nanoparticles contributes to the higher loading amount and turnover frequency (TOF) values compared to counterparts without gamma-MPS and PVP.