CO2选择性氧化乙苯制苯乙烯

本文评述了近年来国内外利用温室气体CO₂选择性氧化乙苯制苯乙烯的研究进展.和乙苯直接脱氢法相比,新工艺不仅能降低反应温度,大幅度降低能耗,还能在一定程度上抑制催化剂的失活.氧化铝负载的Fe系催化剂和活性炭负载的La等过渡金属改性的V系催化剂具有较好的催化活性.CO₂对乙苯脱氢的显著促进作用要归因于金属氧化物催化剂的氧化还原机制以及乙苯脱氢和逆水煤气变换反应耦合的协同作用.尽管新工艺显示了良好的应用前景,但在将来的研究工作中还要强化催化剂失活机理的研究,开发新型高效催化剂并对新工艺的成本进行详细的评估。

Selective Oxidation of Ethylbenzene to Styrene with Carbon Dioxide

The dehydrogenation process for the production of styrene (ST) based on the selective oxidation of ethylbenzene (EB) with the major global warming gas CO 2, is reviewed. The usage of CO 2 instead of steam could provide several advantages such as reduction of the reaction temperature, remarkable energy saving in the distillation process of ST, restraining deactivation of catalysts to some degree, and so on. The iron-oxide-based catalysts and the vanadium-oxide-based catalysts are highly active and promising catalysts for the new reaction system. The mechanism of CO 2 oxidation is also discussed. It can be concluded that the remarkable promoting effect of CO 2 on the dehydrogenation of EB is due to both redox cycle of oxide catalyst and coupling of EB with reversed water gas shift reaction. Although the application of CO 2 is very effective, the catalysts deactivation mechanism, suitable measures to enhance their catalytic stability and the economic evaluation on the new process must be further investigated.