Renewable hydrogen production by ethanol steam reforming using catalysts supported on silica derived from residual biomass

Hydrogen stands out as one of the most promising energy carriers for the future due to its availability and production flexibility. It is essential to develop technologies that utilize renewable feedstocks to enable more sustainable hydrogen production. In this context, the present work focuses on hydrogen production from ethanol using nickel catalysts supported on silica derived from biomass residues, such as rice husk and sugarcane bagasse. To enhance the basicity of the NiSi catalyst derived from rice husk, dolomite was added as a promoter to improve its activity. The catalysts were synthesized via wet impregnation and characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), N 2 physisorption, temperature-programmed reduction (TPR), CO 2 temperature-programmed desorption (TPD), thermogravimetric analysis (TGA), differential thermal analysis (DTA), and Raman spectroscopy. The silica-supported catalyst prepared from rice husk and promoted with dolomite exhibited higher ethanol conversion and hydrogen yield during steam reforming reaction at temperatures between 400 and 600 °C, demonstrating the effect of basicity on catalytic activity. All catalysts showed good stability during 30 h of reaction at 500 °C, although higher coke formation was observed for the rice husk–derived catalyst promoted with dolomite.