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本文应用程序升温脱附技术(TPD),以乙酸作为分子探针,考察了无铬Fe—K系混合氧化物乙苯脱氢催化剂的表面碱性。Fe—K系催化剂表面至少存在两种强度不同的碱中心,其中强碱中心b态对乙苯催化脱氢贡献较大;而催化剂表面同时具有适当的碱强度和密度是获得较好催化性能的重要条件。研究结果还发现,乙苯脱氢反应可能类似于强碱催化的双分子消除E2反应,其中催化剂表面碱位起着类似于E2历程中强碱试剂的作用。
In this paper, the temperature-dependent desorption technology (TPD) was applied to investigate the surface alkalinity of a chromium-free Fe-K mixed oxide catalyst for ethylbenzene dehydrogenation using acetic acid as a molecular probe. There are at least two kinds of alkali centers with different intensities on the surface of Fe-K catalyst, among which, the b-state of strong base contributes greatly to the catalytic dehydrogenation of ethylbenzene; while the catalyst surface has appropriate alkali strength and density to obtain good catalytic performance Important condition. The study also found that the ethylbenzene dehydrogenation reaction may be similar to the strong base-catalyzed bimolecular elimination of the E2 reaction, in which the basic surface of the catalyst acts like a strong base reagent in the E2 process.