QENS shows that methanol is immobile in a fresh ZSM-5 catalyst and one used for conversion at 623 K, but undergoes isotropic rotation within the mesopores generated 673 K.

This work investigates the acid sites in a commercial ZSM-5 zeolite catalyst by combination of spectroscopic and physical methods. The Brønsted such catalysts are associated with aluminum substituted into lattice, which may not be identical to total content zeolite. Inelastic neutron scattering spectroscopy (INS) directly quantifies concentrations protons, silanol groups, hydroxyl groups extra-framework species. INS measurements show that ∼50% this particular is extra framework, conclusion...

Steam de-alumination is used to prepare a H-ZSM-5 material representative of industrial acid zeolite catalysts. Characterisation shows extensive loss acidity but minimal framework crystallinity in the treated material. The material's interaction with propene probed by means inelastic and quasielastic neutron scattering, providing information on reactivity mobility respectively. These results are compared those previously obtained for untreated zeolite. steaming treatment resulted decreased...

We report the characterisation of zeolite ZSM-5 catalysts used in conversion dimethylether to hydrocarbons. Inelastic neutron scattering spectroscopy, supported by solid state NMR, shows that more rapid deactivation occurring with compared methanol is associated formation less methylated aromatic coke species and attributed lower levels water present during conversion. The ability inelastic probe a working catalyst no sample preparation demonstrated.

The properties of 1-octene adsorbed in zeolite ZSM-5 at 293 K are studied by means inelastic and quasielastic neutron scatterings (INS QENS) to investigate interactions relevant the solid acid catalysis fluidized catalytic cracking reactions. INS spectrum is compared that recorded for alkene reveals significant changes bonding on adsorption ambient temperatures; attributed oligomerization form a medium chain n-alkane or cation. QENS analysis shows these oligomers immobilized within pore...

How the methyl torsion transition energy in unsaturated systems is affected by its environment investigated. It strongly influenced both immediate neighborhood, (the number of groups present molecule) and intermolecular interactions. clear that interactions have a major influence on energy, as demonstrated unambiguously previously for mesitylene also seen here other systems. In part, this may be caused fact rarely pure mode (unless enforced symmetry). Where crystal structure available,...

The application of neutron scattering techniques (inelastic scattering, quasi-elastic and diffraction) to explore concepts connected with the methanol-to-hydrocarbon reaction over zeolite ZSM-5 are considered. Reproduced from [ Cat. Sci. Tech. , 2018, 8 3304–3312] under a Creative Commons Attribution Licence (CC-BY).

The techniques of quasi-elastic and inelastic neutron scattering (QENS INS) are applied to investigate the oligomerization propene over a ZSM-5 zeolite. Investigations performed at low temperatures, allowing identification onset reaction observation low-energy spectral changes due intermediate formation that difficult observe by optical methods. Oligomerization proceeds via hydrogen-bonded precursor an interaction with internal acid site followed protonation chain growth being rate-limiting...

The interaction between ZSM-5 and propene over the temperature range 140–373 K is investigated by application of inelastic neutron scattering spectroscopy.

Abstract The reactivity of methanol and methyl acetate mixtures over a HZSM-5 catalyst is studied period 6 h at 350 °C, with small molecular weight olefins aromatic compounds observed as reaction products. Post-reaction analysis the shows coke content to increase content. Vibrational spectra (DRIFTS inelastic neutron scattering, INS) indicate major hydrocarbon species present in coked catalysts be methylated molecules, INS indicating greater degree methylation used higher extent deactivation...

This article reviews recently published work showing how inelastic neutron scattering spectroscopy can be used to identify species found in zeolite ZSM-5 as a catalyst for conversion of methanol hydrocarbons. The advantages and disadvantages the technique are illustrated, current challenges identified.

Abstract The nature of the hydrocarbon pool at different stages methanol‐to‐hydrocarbons reaction over ZSM‐5 is examined. A combination testing, analytical and spectroscopic techniques employed to investigate changes in form as a function conditions time. It shown that inelastic neutron scattering spectroscopy (INS) complements other methods for observing molecular components working catalysts. INS uniquely able spectroscopically identify coke species present deactivated

A role for propene as an intermediate in methanol-to-hydrocarbons chemistry over H-ZSM-5 is considered.

The cracking reactions of 1-octene over H-ZSM-5 zeolite are studied via micro-reactor and off-line spectroscopic techniques a period up to 72 hours on stream temperature range 473 – 673 K. 1-Octene is found react two-cycle hydrocarbon pool mechanism, with strong similarities that reported for methanol-to-hydrocarbons chemistry. This dual-cycle mechanism requires temperatures K or higher function full efficiency, lower deactivating portions the cyclic leading premature deactivation catalyst...

Abstract The adsorption of methanol in HZSM-5 at low temperatures has long been regarded as an associative process involving hydrogen bonding to the acidic zeolite hydroxyl groups. Recent studies employing inelastic neutron scattering spectroscopy (INS) have reported that complete dissociation methoxylate occurs 298 K, and infrared evidence for a partial K also described. Here we investigate apparent contradictions between different techniques, using combination INS, solid-state NMR...

Quasi-elastic neutron scattering (QENS) and molecular dynamics (MD) simulations are applied in combination to investigate the of methane H-ZSM-5 zeolite catalysts used for methanol-to-hydrocarbons reactions. Methane is employed as an inert model methanol reaction feedstock, studies made fresh catalyst with varying levels coke buildup effect coking on reactant mobility. Measurements temperature range from 5 373 K. mobility under these conditions found be extremely high ZSM-5, majority...

Phenol hydrogenation is widely studied for selective production of the chemical intermediate cyclohexanone. A plethora studies in literature have reported catalysts aiming to achieve high selectivity compared Pd/C. However, we demonstrate that and high-yielding reactions are inherent features liquid-phase phenol using conventional Pd/C catalysts. We also show there a very strong dependance upon conversion, with being maintained until near complete consumption phenol, after which subsequent...

Neutron scattering methods such as quasielastic neutron (QENS) and inelastic (INS) have been used to study the reactivity of propene 1-octene over acid zeolite catalyst H-ZSM-5. The high activity causes alkenes form linear oligomers below room temperature. INS has shown that reaction proceeds through a hydrogen-bonded intermediate. Studies using propane an inert analogue for found adsorbed C3 molecules spend much their time undergoing short jumps within pore channels zeolite. Hydrothermal...