Highly dispersive Cu species constructed in mesoporous silica derived from ZSM-5 for batch and continuous adsorptive desulfurization of thiophene

Abstract

ZSM-5 zeolite with long narrow pore structure could restrict the adsorption of sulfur compounds from commercial fuels due to their larger molecular dimensions. Herein, ZSM-5 as silica precursor and CTAB as template was successfully employed using dissolution and self-assembly method to synthesize micro-mesoporous silica (MMZ). Compared with ZSM-5, MMZ materials could effectively overcome the diffusion pathway, enhance mesopores and enlarged the BET surface area (830 m2/g). After MMZ crystals were fabricated with 5-20 wt% Cu content by ultrasound facilitated impregnation strategy, the active sites were improved, which promoted thiophene adsorption capacity from 0.9 to 0.44 and 0.48 mmol/g via π-complexation conducted under dynamic (flow) conditions in a fixed bed adsorber and batch stirring tang reactor, respectively. And the desulfurization performances decline in the order 10Cu/MMZ >20Cu/MMZ > 5Cu/MMZ >10Cu/ZSM-5 > MMZ > ZSM-5. The higher adsorption capacity was tentatively linked with well dispersive Cu nanoparticles (NPs) and textural properties of MMZ. Furthermore, the ADS activity of Cu/MMZ towards thiophene can be recovered well without nominal loss.