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 gcat-1 at 20 °C. Although the catalytic activity decreased after use, it could be restored easily by regenerating in acetic acid solution.

Closing the hydrogen cycle with the couple sodium borohydride‐methanol, via the formation of sodium tetramethoxyborate and sodium metaborate

“…Second, the aforementioned stoichiometry implies an effective gravimetric hydrogen capacity of 4.8 wt% for the couple NaBH 4 ‐CH 3 OH, and this is a clearly promising capacity. In addition, the HGR was calculated to be 331 mL(H 2 ) min −1 (without catalyst), which is one of the best performance for an uncatalyzed solvolysis reaction involving a hydride and a protonic solvent; some examples are shown in Table 1 21,22,30,64‐74 …”

“…In addition, the HGR was calculated to be 331 mL(H 2 ) min −1 (without catalyst), which is one of the best performance for an uncatalyzed solvolysis reaction involving a hydride and a protonic solvent; some examples are shown in Table 1. 21,22,30,[64][65][66][67][68][69][70][71][72][73][74] The as-formed NaB(OCH 3 ) 4 can be readily hydrolyzed into NaB(OH) 4 , and 4 equiv CH 3 OH are generated. The cycle is then neutral in CH 3 OH.…”