Protonated Poly(ethylene imine)-Coated Silica Nanoparticles for Promoting Hydrogen Generation from the Hydrolysis of Sodium Borohydride

Abstract

Nonmetal catalysts are attracting a great deal of attention because of their advantages including high activity, low cost, and environmental friendliness. In this work, a nonmetal catalyst for NaBH₄ hydrolysis was fabricated through covalent modification of silica nanoparticles with protonated poly(ethylene imine). The successful formation of the catalyst was verified by transmission electron microscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The fabricated catalyst shows excellent activity in catalyzing NaBH₄ hydrolysis reactions. The hydrolysis of 15 mg NaBH₄ catalyzed by 50 mg catalyst could provide a hydrogen generation rate as high as 117.53 mL min^-1 $g_{\mathrm{cat}}^{-1}$ at 20 °C. Although the catalytic activity decreased after use, it could be restored easily by regenerating in acetic acid solution.

Keywords: heterogeneous catalysis; hydrogen generation; nanoparticles; polymers; silica.