Effect of Preparation Processes on Catalytic Performance of PtSnNa/ZSM-5 for Propane Dehydrogenation

The effect of different preparation processes (impregnation and agglomeration) on the performance and properties of PtSnNa/ZSM-5 catalyst for propane dehydrogenation was studied. Some methods such as BET surface area measurement, catalyst particle mechanical strength, temperature-programmed desoption of ammonia (TPDA), Solid-state 27Al MAS NMR spectroscopy and temperature-programmed reduction of hydrogen (H2-TPR) were used to characterize the catalysts. The channel of ZSM-5 was hardly blocked after adding the binder despite the sequence of agglomeration and impregnation. Meanwhile the Pt metal dispersion on the preimpregnating catalyst with 5 wt % binder was the highest and the acidity was the weakest. The experimental results of propane dehydrogenation reaction showed that the preimpregnating catalyst with 5 wt % binder indicated the optimum reactivity in three catalysts. Therefore, the preimpregnating method in the case of adding a small amount binder was the optimal preparation method of the catalyst, which could replace the conventional preagglomerating method. Finally, a model for the effect of preparation processes on catalytic performance of PtSnNa/ZSM-5 catalyst was proposed.