Highly active and durable hydrogen release in NaBH4 methanolysis reaction with sulphur and phosphorus-doped metal-free microalgal carbon nanoparticles

Herein, activated carbons prepared from microalgae with KOH activation (C-KOH) used for sulphur (S) and phosphorus (P) doped metal-free carbon catalysts (C-KOH-S-P, C-KOH-S) for the first time with hydrogen release in NaBH4 methanolysis reaction (NaBH4-MR). The metal-free carbon catalysts were characterized by X-ray photoelectron spectroscopy (XPS), scanning electron microscope (SEM-EDS), X-ray diffractometer spectroscopy (XRD), Fourier-transform infrared spectroscopy (FTIR), nitrogen adsorption, and elemental analysis (CHNS) methods. Hydrogen generation rate (HGR) for the NaBH4-MR for C-KOH-S-P metal-free catalyst (10 mg) was 13,000 mL min-1 g-1. The activation energy (Ea) value for C-KOH-S-P was found to be 25.02 kJ mol-1. For the C-KOH-S-P catalyst, about 59 % of the first catalytic activity was retained after the fifth run. A new strategy with the S and P doped metal-free carbon catalysts obtained in this study can be provided for environmentally friendly efficient catalytic reactions.