A series of Mo-impregnated H\%β\% samples, with MoO\-3 loading in H\%β\% zeolite in the mass fraction range of 0\^5%\_6\^0%, were studied by means of XRD and IR in order to characterize their structures. Mo/H\%β\% samples′ crystallinity almost linearly decreases with increasing the amount of MoO\-3 loaded. The IR spectra and XRD patterns suggest that the progressive destabilization of the H\%β\% zeolite structure is caused by increasing Mo loading in (MoO\-3+H\%β\% zeolite). During the calcination, Al\-2(MoO\-4)\-3 formed from the dealumination of H\%β\% zeolite, causes the substantially partial breakdown of the zeolite framework when the Mo loading in MoO\-3+H\%β\% is relatively high.
Effect of reaction temperature and pressure on the metathesis reaction between ethene and 2-butene to propene was studied on the WO3/γ-Al2O3-HY catalyst. The activity is found to increase with elevated temperature and reaches a plateau at 150-240 ℃. After that, the activity undergoes a remarkable decrement at too high temperature. The effect of temperature is elucidated by the oxidation state of tungsten species. The evaluation results also indicate that the stability is dependent on this reaction parameter. Medium pressure （0.5-0.8 MPa） is favorable for stability, while atmospheric pressure or too high pressure （〉1.0 MPa） deteriorates the stability. For explanation, UV Vis, FT-IR, O2-TPO, and TG techniques are used to characterize the spent catalysts.
