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摘要: 采用溶胶-凝胶法制备了Fe-Mo-O催化剂,用XRD、TEM、BET、IR、TPR、TPD和微反等技术研究了催化剂晶体结构、表面构造、晶格氧活泼性、化学吸附和乙烷部分氧化反应性能。Fe-Mo-O复合氧化物催化剂是由超细微粒组成,微粒粒径约10 nm~20 nm,比表面积为48.1 m2/g。催化剂表面由Lewis碱位(Mo=O键的端氧和Fe-O-Mo键中的桥氧)及Lewis酸位构成。乙烷能以甲基中的H原子吸附在催化剂表面Lewis碱位Mo=O的端氧上形成分子吸附态,其部分氧化产物主要是C2H4和少量的CH3CHO。
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关键词:
- 溶胶-凝胶技术 /
- 乙烷部分氧化 /
- 超细Fe-Mo-O催化剂
Abstract: Fe-Mo-O catalysts were prepared by the Sol-Gel method. The surface composition, reducibility, ethane chemisorption and reactivity of the catalysts were systematically studied by using the techniques of XRD, IR, TPR, TPD and micro-reactor. The results showed that the catalyst calcined at 450 ℃ was ultrafine particles with BET surface area of 48.1 m2/g. There existed both Lewis acid sites(Fe3+,Mo6+) and Lewis base sites(oxygen of Mo=O and Mo-O-Fe bond) on the surface of the catalysts. Ethane can be chemisorbed on surface terminal oxygen of Lewis base sites Mo=O bonds by one H atom in -CH3 to form molecular adsorption states, and the adsorption ability increases with the rising of the temperature. Moreover, the ultrafine particles have higher lattice oxygen activity, and the adsorption amount and intensity of ethane on the ultrafine particles is greater than that on the bigger particles. Reaction products of partial oxidation of C2H6 on the Fe-Mo-O catalyst are mainly C2H4 and a little CH3CHO.-
Key words:
- sol-gel method /
- ethane partial oxidation /
- Fe-Mo-O catalyst
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