Preparation,Characterization And Hydrogenation Perform Ance Of Monolithic Palladium/Cordierite Catalysts

Abstract:To solve the internal diffusion problem brought by coating on monolithic catalysts. The preparation of uncoating palladium/cordierite monolithic catalysts is the target in this article. We use silane coupling agent to modified cordierite, make it surface grafted on specific functional groups to anchor palladium particles and improve catalysts performance. To test the activity of catalysts and optimize the preparation process, hydrogenation of styrene, hydrogenation of COD are chosen as the model reaction.The cordierite was firstly modified by APTS and loaded palladium particles. FT-IR, XRD, TEM and ICP were used to characterize cordierite surface elements, Pd particle crystalline state, size of Pd particle and the amount of Pd loaded. Through PE hydrogenation test the activity of catalysts and get the optimum preparation process.The influence of different functional groups were studied, APTS(amino), APED(diamine), APDT(triamine), KH560(epoxy), KH590(thiol), KH703(chlorine) were used to modify cordierite. COD hydrogenation activity and intermediate COE selectivity were used to evaluate the performance of the catalysts. The result show that the introduction of amino make COD tend to depth hydrogenation, and the catalyst grafted epoxy show higher COD conversion rate as well as COE selectivity. XPS reveal that different functional group change Pd3d5/2binding energy so the catalyst show different COE selectivity. On this basis the influence of modification solvent, precursor and ultrasonic impregnation were investigated. When using toluene as solvent, Pd(acac)2as precursor and ultrasonic impregnation, the catalyst show the highest COD conversion and the COE selectivity up to92%. This study achieve a method to prepared uncoating Pd/cordierite monolithic with good activity, show a certain application prospect.