Unravelling the effect of impurities on the methanol-to-olefins process in waste-derived zeolites ZSM-5

One of the main challenges in next decades for chemical industry is valorization low-grade industrial waste streams into valuable materials, as their increasing amount can have a major environmental impact. For example, copper mining industry, flotation tailings be valorized solid acid catalysts, such zeolites. Numerous studies shown that modification zeolites by metal ions has positive effect catalytic performance. However, presence impurities waste-derived materials usually disregarded. In this work, influence ZSM-5 on physicochemical properties and performance methanol-to-hydrocarbons (MTH) reaction was investigated. Flotation from mainly consist SiO2 quartz, to Ca, Mg Fe species. By altering pH precipitation step, content could controlled. Chemical analysis confirmed Fe, Ca low concentrations samples. UV–Vis Diffuse reflectance spectroscopy (DRS) electron paramagnetic resonance (EPR) showed different species samples form isolated Fe3+, oligomeric FexOy some extended Fe2O3-like clusters. Temperature programmed desorption (TPD) NH3 infrared (IR) measurements after CO pyridine adsorption were used order probe cations present acidity materials. It found zeolite material with higher contained less Brønsted sites more Lewis sites. Catalytic testing had overall catalyst stability yields towards ethylene propylene respectively 8% 6% up. Meanwhile, operando DRS mechanism, its increase led formation hydrocarbon pool This study not only show transformed value-added namely zeolite-based material, but also further improve catalyst.