Response surface optimization of KIT-6 mesoporous silica synthesis using sapindus rarak bio-template for dye removal and waste cooking oil pyrolysis

Abstract

Hybrid-templated KIT-6 mesoporous silica was synthesized using Pluronic P123 and Sapindus rarak extract as dual templates. The synthesis was optimized using Response Surface Methodology (RSM) to evaluate the structural and textural properties. The effects of the P123/SRE ratio, n-butanol/TEOS ratio, and total surfactant content on the mesopore diameter, pore volume, and surface area were systematically investigated. Nitrogen adsorption-desorption, SAXRD and TEM confirmed the formation of mesoporous structures with tunable pore sizes (3.78-6.79 nm) and high surface areas (359-650 m 2 /g). Adsorption tests using methylene blue achieved capacities of up to 58.2 mg/g, with mesopore diameter, pore volume, and surface charge identified as the primary factors governing adsorption efficiency. The dual-template KIT-6 was applied as a catalyst for the pyrolysis of waste cooking oil (WCO), achieving high liquid yield and hydrocarbon selectivity up to 84.4% may be associated with the favorable textural properties of the KIT material, including its relatively high specific surface area, pore diameter, and mesopore volume. These characteristics may provide good pore accessibility for the interaction of reactants and products within the mesoporous network and facilitate deoxygenation reactions and hydrocarbon formation. Response surface analysis highlighted the balanced interactions between P123, SRE saponins, and n-butanol in influencing pore connectivity and uniformity.