Hydrogen Generation from NaBH4 Methanolysis with Ru/AC Catalyst Synthesized by Microwave Reduction Method

Spent coffee grounds (SCG), a large waste stock worldwide was converted into activated carbon (AC) with ZnCl2 chemical activation. The activated carbon was used as a supported material for the production of Ru catalyst. Ru/AC catalysts were synthesized by different methods and at different ratios and they were investigated as a catalyst for hydrogen generation from NaBH4 methanolysis. Ru doping on activated carbon was performed by NaBH4, UV, and microwave reduction methods and the hydrogen generation capacities were determined. The highest catalytic activity was found in the catalyst that was produced by the microwave reduction method. Among the Ru/AC catalysts synthesized at different ratios by the microwave reduction method, the 5% Ru/SCGZ4-600 catalyst provided the highest hydrogen generation rate. To determine the microwave reduction conditions, the effect of microwave time and temperature on the hydrogen generation rate (HGR) was also investigated. The highest HGR value was found at 15 min and 150 degrees C synthesis conditions. 52,202.4 mL/(min g(cat)) was obtained in the presence of 0.05 g catalyst, 1.25% NaBH4, 10 mL methanol, and 60 degrees C. The activation energy with 5%Ru/SCGZ4-600 catalyst was found to be 15.33 kj/mol.