CO2 气氛下 MCF 负载氧化钒催化剂上乙苯脱氢反应

 以介孔氧化硅泡沫 MCF 为载体合成了一系列负载型氧化钒催化剂 (V 含量为 2%?10%). 采用 N2 吸附、X 射线衍射和 H2 程序升温还原对 V/MCF 催化剂的结构和织构性质进行了表征, 并评价了催化剂在 CO2 气氛下的乙苯脱氢性能. V/MCF 催化剂具有较高的乙苯脱氢活性, 其中 V 含量为 6% 的催化剂具有最高的反应活性. V/MCF 催化剂的乙苯脱氢活性显著高于 V/MCM-41, 这是由于前者具有较高的可还原性以及较好的扩散性能. CO2 气氛下的乙苯转化率明显高于 N2 气氛下的, 这归因于 CO2 与乙苯发生氧化脱氢, 并通过逆水煤气变换反应在线除去脱氢反应生成的氢.

Ethylbenzene Dehydrogenation in the Presence of CO2 over MCF-Supported Vanadium Oxide Catalysts

A series of vanadia catalysts supported on mesocellular silica foam (MCF) with a V content ranging from 2% to 10% were studied with respect to their performance in the dehydrogenation of ethylbenzene (EB) to styrene in the presence of CO2. The structural and textural characterization of these catalysts was done using N2 adsorption, X-ray diffraction, and temperature-programmed reduction. These catalysts were found to be effective for the dehydrogenation reaction and the 6%V/MCF catalyst showed the highest activity. The MCF-supported vanadia catalysts exhibited far higher activity than their conventional V/MCM-41 counterparts, which can be attributed to the higher reduci-bility and better diffusion of reactants and products in the former catalysts. A higher conversion was obtained during EB dehydrogenation with CO2 than with N2. This is due to the oxidative dehydrogenation of EB with the help of oxygen that originates from CO2 as well as the coupling of EB simple dehydrogenation with the reverse water-gas shift reaction.