Low temperature conversion of linear C4 olefins using acid ZSM-5 zeolites with aluminum concentration gradient

Reaction pathway and kinetics of C3–C7 olefin transformation over high-silicon HZSM-5 zeolite at 400–490°C

“…The oligomerization are mainly considered at low temperatures (<400ºC) [11,12]. The multimolecular reactions, e.g., dimerization, trimerization and etc., of the parent olefin are initiated and followed by the secondary reactions such as isomerization or cracking, yielding a variety of derivative olefins [2,13].…”

Atomic spectrometry update: review of advances in the analysis of metals, chemicals and materials

“…The techniques of XRD and TEM were used to determine the crystal phase and particle size. The "depth proling" ability of SIMS was also utilized by Henry et al 324 to determine Al gradients across synthesized ZSM-5 zeolite crystals produced for C 4 olen conversion. An Ar + primary ion beam was used to sputter an area 200 Â 200 mm.…”

Recent advances in secondary ion mass spectrometry of solid acid catalysts: large zeolite crystals under bombardment

“…For example, the Si/Al ratio can vary throughout the crystal with gradients perpendicular to the surface 41 having implications on both crystal growth and the distribution of catalytic activity. Henry et al have reported recently on sputter depth profiling analysis of the Si/Al ratio on various powder H-ZSM-5 catalyst samples, 42 yielding an average value for the Si/Al ratio with progressing Ar + sputtering time, i.e. depth.…”