Fabrication of protonated chitosan/montmorillonite catalyst for hydrogen production via sodium borohydride in the optimum methanol/propylene glycol mixture

Abstract

Hydrogen (H-2), an energy carrier, is among the advanced energy technologies. In the study, a hybrid metal-free catalyst was provided by protonation of chitosan dispersed on montmorillonite (Chit-Mont-H) using calcination and hydrothermal methods. Highly active H-2 release via sodium borohydride (NaBH4) using Chit-Mont-H in propylene glycol, methanol or propylene glycol/methanol mixture was performed as a first in the literature. H-2 generation rate (HGR) values in methanol and methanol/propylene glycol were 6743 and 23,536 mL min(-1)gcat(-1), respectively. There is a significant increase of approximately 4 times in the HGR values in methanol/propylene glycol compared to methanol. The catalysts by X-ray photoelectron spectroscopy (XPS), X-ray powder diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), energy dispersive X-ray analyser (EDS), and Transmission electron microscopy (TEM) analyses were characterized. The activation energy (Ea) value was calculated as 27.53 kJ mol(-1). Also, the mechanism of H-2 release in a mixture of methanol/ propylene glycol by Chit-Mont-H was proposed.