‘H magic angle spinning nuclear magnetic resonance (MAS NMR) measurements on ZSM-5 synthesized with tetrapropylammonium ions as structure-directing template, calcined and hydrogen exchanged, indicate high concentrations of silanol groups (up to 4.6~ 10zo SiOH g-‘)_ ‘H NMR, “Na and % MAS NMR studies of zeolites ZSM-5 with different Si/Al ratios support a model which attributes the majority of th...

An investigation was carried out of the oxidative carbonylation of methanol to dimethyl carbonate over Cu-ZSM-5. The catalyst was prepared by solid-state ion exchange of H-ZSM-5 with CuCl and then characterized by X-ray absorption spectra (XAS). The XANES portion of the XAS data showed that all of the copper is present as Cu+ cations, and analysis of the EXAFS portion of the data shows the Cu+ ...

In this study, hierarchical H-ZSM-5 zeolite is prepared via post-synthetic modification of parent H-ZSM-5 zeolite (Si/Al=35) synthesized from bagasse (BGA) as silica source using desilication with alkaline treatment (AT). For optimizing the effective parameters on desilication, Taguchi method was utilized. Cultivated BGA in the south of the Caspian Sea (Mazandaran province, Iran) is applied for...

The tetralin hydrocracking process into benzene, toluene, and xylenes (BTX) was investigated over metal-modified (Ga, Nb, Ni, NiMo, Sn, W, Zr or H3[P(W3O10)4])/ZSM-5 zeolite catalysts without sulfidation procedures, mechanism analyzed, compared with a pristine microporous material in packed bed reactor under applied atmospheric pressure (p). This experimental study presents an investigation of ...

Upgrading of cracked PFO (Pyrolysis fuel oil) for production of fuels, such as gasoline and light gasoil, was carried out in a semi batch reactor. Two different kinds of mesoporous and microporous catalysts, MCM-41 and ZSM-5, were used. Modification methods, such as ion exchange and impregnation with Fe and Ti, were done for tuning the acidity of the catalyst. XRD, FT-IR, and XRF analyzes were ...

I n this issue of PNAS, Schoonheydt, Solomon, and coworkers (1) definitively characterize the structure of the Cu-ZSM-5 site that oxidizes methane to methanol. With the successful correlation of a specific copper-oxy structure to such reactivity, the importance of this work extends beyond hydrocarbon oxidation on zeolites. This breakthrough potentially has farreaching implications in both the f...