Synthesis flow impregnation

Zeolite-supported Re catalysts have been synthesized by chemical vapor deposition (CVD) ofMTO (CH3Re03) (3) on various zeolites such as HZSM-5, H-Beta, H-USY and H-Mordenite. HZSM-5 samples with different A1 contents were prepared by a hydrothermal synthesis method. For comparison, conventional impregnated catalysts were also prepared by an impregnation method using an aqueous solution of NH4Re04. All catalysts were pretreated at 673 K in a flow of He before use as catalyst. 

Fig. 3 Comparison of the activity and reusability data for the direct synthesis of hydrogen peroxide using a 0.5% Au-0.5% Pd/TiOa catalyst synthesized by different strategies. Structural information of the catalyst is also provided. Key CIm conventional impregnation method Sim sol-immobilisation method MIm modified impregnation method Calc the dried catalysts are heated at 400 °C for 4 h under a static air atmosphere Red the dried catalysts are heated at 400 °C for 4 h under a flow of 5% H2 in He. SDCV size dependent compositional variation. The first "Gold rich" catalyst was prepared by the MIm method using a 2M HCl solution and the second "Gold rich" catalyst was prepared by the MIm method using a 2M NaCl solution and the last catalyst was prepared by the MIm method using a IM H2SO4 solution.

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