| Three dimensionally ordered macroporous (3DOM) materials have attacted much research attention in recent years due to their order structure, large specific sueface area and high porosities. Many kinds of3DOM materials have been fabricated by different methods, such as elementary substance, alloy, oxide, chalcogenide and inorganic salt, and they are supposed to have potential application prospect, in the areas of gass separation, gas adsorbtion and catalysis. It was found that the macroporous structure of3DOM materials is in favor of diffusion and transfer of reactant during the catalytic reaction.In the previous work of our group, a microporous MgFe0.1Al1.9O4catalyst was developed and was found to have good catalytic activity in ethylbenzene dehydrogenation with CO2. However, it showed fast deactivation due to the coke formation. So the effective method to prolong the catalyst useful-life is to increase the diffusion rate of the cake precursor.In present work,3DOM MgFe0.1Al1.9O4material was synthetised with poly(methy methacrylate)(PMMA) colloidal crystal as a template and was utilized in the ethylbenzene of dehydrogenation with CO2. Many synthesis conditions of3DOM MgFe0.1Al1.9O4were systematically studied. Monodisperse PMMA sphere with different diameters were obtained though emulsifier-free polymerization technology in consideation of monomer and initiator, and were assembled by different methods. Compared with gravitational sedimentatiaon and vertical sedimentation, centrifugal sedimentation was a time-saving and effective way to prepare the colloid template. The PMMA template was excellently oedered and thermally stable, which was assembled with modified PMMA spheres by acrylic acid under centrifugation. Ethylene glycol-methanol mixed solution of metal nitrates was infiltrated into the void of the colloidal template with infiltrating6h. At last template was removed by calcination and the temperature was raised at a rate of1℃/min.The catalytic performance of ethylbenzene dehydrogenation with CO2over3DOM MgFe0.1Al1.9O4catalyst was investigated. Compared with the microporous catalyst, the3DOM MgFe0.1Al1.9O4catalyst demonstrated the enhanced catalytic stability due to the macroporous structure facilitating the diffusion and transfer of carbon deposition. |
