Crosslinked Clay Catalytic Combustion Of Methane And Ethylbenzene Dehydrogenation Reaction

Montmorillonite is a promising catalyst or catalytic support, but its application under actual circumstance is limited due to the small basal spacing (d001) and the weak thermal stability. In the present research, one kind of raw montmorillonite, from Laiyang of Shandong Province, was pillared by several hydroxyl polyoxocations to prepare the pillared clays (PILC) in order to improve its surface area and thermal stability.(1) The raw montmorillonite was pillared by hydroxyl Al and AIM. (M=Zr, Ce, La, Y) polyoxocations with 20mmol/g of (Al+M)/clay and changing M/Al ratio to make pillared-clay. The d001 of Al-PILC and A1M-PILC measured by X-ray diffraction is 1.86~1.92nm and remains near 1.80nm even calcined at 500°C, while that of raw montmorillonite is only 1.53nm, which suggests the basal spacing of PILC is enlarged and subsequently its thermal stability is improved by Al and AlM pillars. Copper catalysts supported on PILC were prepared and applied in the catalytic combustion of methane. The results show that CH4 conversion over Cu catalysts supported on AlZr- or AlCe-PILC, which exceeds 90% at 550℃ of reaction temperature, is largely higher than that over Al-pillared catalysts, and CH4 conversion over Cu and Mn catalysts supported on A1Y-PILC, Mn catalysts supported on AlZr-PILC, is also higher than that over Al-pillared catalysts, respectively.(2) The raw montmorillonite is pillared by A1-, AlM-(M=Ce, Zr, Y) polyoxocations to make A1-, AlM-pillared clay (PILC), respectively. These PILC samples were characterized by BET surface area and infrared spectra. The A1-, A1M-PILC were used as supports and Fe/Al-PILC, Fe/AIM-PILC catalysts were prepared by ion-exchanged method and applied in the dehydrogenation of ethylbenzene(EB) coupled with reverse shift of water gas. The result shows that Fe/AIM-PILC catalyst has a higher conversion of EB and selectivity of styrene (ST) for the dehydrogenation of EB that the raw clay supported catalyst.(3) The raw montmorillonite was pillared by Ti-polyoxocations, from the hydrolysis of TiCl4, to. form pillared clay, designated as Ti-PILC, which wascharacterized by BET surface area, Infrared spectra and thermal analysis. The characterization results demonstrate PILC has a larger surface area and more hydroxyl groups than that of the rawl clay, was used as the catalytic supports to prepare supported Cu catalysts. The catalytic performance of the above catalysts was evaluated using the catalytic combustion of methane at 400~550℃ of reaction temperature under atmospheric pressure.(4) The raw montmorillonite was pillared by Ti4+ polyoxocations from the hydrolysis of Ti(OC4H9)4 to form pillared clay, designated as Ti-PILC, which was characterized by BET surface area and Infrared spectra. The characterization results exhibit PILC has a larger surface area and more surface hydroxyl groups than that of the raw clay, was used to prepare supported Cu catalysts. The catalytic performance of the above catalysts for methane combustion was evaluated at 400~550°C of reaction temperature under atmospheric pressure.(5) The raw montmorillonite was pillared by Ti-Si-polyoxocations to form pillared clay, designated as Ti-Si-PILC, which was characterized by BET surface area, Infrared spectra and thermal analysis. The characterization results show PILC has a larger surface area and more hydroxyl groups than that of the raw clay, was used as the catalytic carriers to prepare supported Cu and Mn catalysts, respectively. The catalytic performance of the above catalysts was tested using the combustion of methane at 400~550℃ of reaction temperature under atmospheric pressure.