Metal-Free Coal Catalyst for Hydrogen Production: Synthesis and Performance Assessment

Abstract

In this study, a coal-based catalyst produced by protonating phosphoric acid was used as a metal-free catalyst for hydrogen production from sodium borohydride (NaBH4) methanolysis. Experiments were conducted with various acid concentrations, impregnation times, and carbonization temperatures and times in order to produce a metal-free coal catalyst with enhanced catalytic activity. The catalyst impregnated with 3M H3PO4 for 12 h and subsequently carbonized at 600°C for 90 min exhibited the highest catalytic activity. The hydrogen production at 60 °C methanolysis with 0.25 g of NaBH4 catalyzed by a metal-free coal catalyst was found to be 11,854 mL min−1g.cat−1. Additionally, the activation energy of the catalyst was determined to be 22.5 kJ mol-1.