Surface functionalization of SBA-15 with organosilane for the preparation of bimetallic Ni-Co/SBA-15 catalyst: An innovative approach to convert waste cooking oil into advanced biofuel energy

This research investigates the utilization of bimetallic nickel-cobalt supported SBA-15-silane catalysts for the production of green diesel from waste cooking oil (WCO), aiming at sustainable energy solutions. The catalysts underwent surface-functionalization with three distinct silane types: mercaptosilane (-SH), aminosilane (-NH2), and phenylsilane (-Ph). Notably, the incorporation of -NH2 silane in the fabrication of bimetallic NiCo/SBA-15-NH2 catalyst led to significant improvements in catalyst properties. Specifically, enhancements were observed in pore characteristics, with a surface area of 424 m2/g and a pore size of 4.8 nm, along with an increase in acidity to 5038.91 μmol/g. This rise in acidity is attributed to the presence of amino groups (-NH2), which foster stronger electrostatic interactions between the support and nickel-cobalt particles, subsequently affecting the particle size of Ni-Co (as confirmed by HRTEM analysis). Parametric studies unveiled the superior performance of the NiCo/SBA-15-NH2 catalyst, demonstrating a notable hydrocarbon yield of 80 % and diesel selectivity of 90 % at a reaction temperature of 300 °C, with sustained optimal performance for up to 6 h of reaction time. Furthermore, the blended green diesel (G2.5 & G5) derived from this process exhibited favorable fuel properties including lower kinematic viscosity, higher cetane number, and lower pour point in comparison to commercial petrol-diesel. These findings underscore the significant potential of silane in catalyst preparation for the conversion of WCO into biofuel energy, thereby highlighting a promising avenue for sustainable energy production and waste management.