Weili Wan, Tingjun Fu, Ruiyue Qi
Dec 16, 2016
Citations
0
Influential Citations
25
Citations
Journal
Industrial & Engineering Chemistry Research
Abstract
This investigation focused on the study of formation mechanism for highly mesoporous ZSM-5 under the introduction of tetrapropylammonium hydroxide (TPAOH) during NaOH treatment. Determined based on N2 sorption, transmission electron spectroscopy, scanning electron spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy, inductively coupled plasma atomic emission spectroscopy, and 29Si magic-angle spinning nuclear magnetic resonance characterizations, increased mesoporosity, crystallinity, and surface integrity for the desilicated ZSM-5 were found after TPAOH introduction. This protective effect of tetrapropylammonium (TPA+) on desilication was reflected by increased surface SiO2/Al2O3 ratios with increased concentrations of TPA+. TPA+ was first confirmed to be mainly adsorbed on the Si(4Si, 0Al) sites to provide a protective effect. Na+ played an indispensable role in the induced desilication during alkali treatment. The co-effect of protective desilication from TPA+ and preferential desilicatio...