Development of New Catalyst for the Dehydrogenation of iso-Butane to iso-Butene

一种汽油添加剂甲基丁基醚（MTB）被认为可以改善机动车尾气的排放。然而，异丁烯作为结核分枝杆菌生产的主要原料的量是有限的。本研究旨在开发异丁烷脱氢制异丁烯的新催化剂。提出了载铁活性炭作为异丁烷脱氢反应的活性催化剂。此外，负载铁的活性炭催化剂的活性在异丁烷与二氧化碳共投料时得到了提高。二氧化碳的活性增强是由于还原铁被二氧化碳氧化到更高的氧化态。铬负载活性炭催化剂和氧化钒负载活性炭催化剂在异丁烷脱氢反应中表现出相似的催化活性。二氧化碳对负载钒的活性催化剂有显著的促进作用。然而，在二氧化碳的存在下，负载钒的SiO_2或Al_2O_3催化剂的催化活性下降。少量锶、钡、碳酸钙的共载可提高氧化钒活性炭催化剂的催化活性。碱土金属与氧化钒共载量为10mol %时，其含量最佳。负载水平的进一步增加降低了催化活性。

An additive for gasoline, methyl t-butyl ether(MTB) is known to improve emission from exhaust gas from motor vehicles. However, the amount of iso-butene a principal feed for MTB production is limited. This research is aimed to exploit new catalysts for the dehydrogenation of iso-butane to iso-butene.Iron-loaded activated carbon was proposed as an active catalyst for the dehydrogenation of isobutane. In addition, the activity of the iron-loaded activated carbon catalyst was promoted in the co-feeding of iso-butanme with carbon dioxide. The enhanced activity of carbon dioxide was attributed to the oxidation of reduced iron species to the higher oxidation state by carbon dioxide.Chromia and vanadium oxide loaded activated carbon catalyst exhibited similar catalytic activity in the dehydrogenation of iso-butane. Promoting effect of carbon dioxide was significant on the vanadium oxide loaded activated catalyst. However, catalytic activities of vanadium oxide loaded SiO_2 or Al_2O_3 catalysts decreased in the presence of carbon dioxide.Catalytic activity of vanadium oxide loaded activated carbon catalyst was promoted with co-loading a small amount of strontium, barium, and calcium carbonates. The amounts of alkaline-earth metal was optimum when it was co-loaded with 10 mol% of vanadium oxide. Further increase in the loading level decreased catalytic activity.