Synthesis of fibrous silica BEA for methanol to olefin reaction

Abstract

Traditional methods of producing olefins largely depend on petroleum fuels, significantly contributing to environmental and sustainability challenges. The Methanol-to-Olefin (MTO) process is a sustainable alternative for producing olefin products, utilizing abundant materials like CO2, coal, natural gas, and biomass. However, the catalytic efficiency of the MTO process utilizing conventional zeolite catalysts is restricted by their relatively low activity, primarily attributable to the zeolite’s microporous shape and high acidity. This study successfully synthesized Beta zeolite featuring a fibrous silica structure using a combination of microemulsion and zeolite seed-assisted methods. The catalysts were characterized using field emission scanning electron microscopy (FESEM), Fourier transform infrared spectroscopy-potassium bromide (FTIR-KBr), nitrogen physisorption, and ammonia-temperature programmed desorption (NH3-TPD). The fibrous silica Beta (HFBEA) appears to have a highly organized spherical structure and a consistent distribution of particle sizes, as confirmed by FESEM analysis. FTIR-KBr further confirms the formation of fibrous silica of synthesized HFBEA while maintaining the framework of Beta seed. Surface analysis revealed that HFBEA has a 35% higher BET-specific surface area and an 86% greater volume of mesopore in comparison to conventional HBEA. NH3-TPD results indicate that incorporating fibrous silica into the BEA structure significantly reduced the catalyst’s acidity. These factors contributed to the outstanding catalytic performance of HFBEA in the MTO process, achieving 95.4% methanol conversion and demonstrating significant selectivity towards light olefins at 78.1%, outperforming the commercial HBEA catalyst.