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在工业生产条件下对催化剂和催化作用的动态研究已经引起重视。吸附热能反映催化剂表面能量状况和吸附分子间的相互作用,是表征催化剂表面性质的重要参量。对于国产甲苯歧化催化剂DFC-1氢型丝光沸石(简称HMDFC-1)的吸附热和催化活性之间关系的报道还不多。在用吸附差热方法考察HMDFC-1的表面酸性时发现,在动态条件下HMDFC-1存在着对NH_3可逆和不可逆两种吸附,而对吡啶则只有不可逆吸附。本文利用脉冲色谱法分别测定了苯、甲苯、二甲苯在HMDFC-1上以及在被NH_3中毒的HM吸附热,和甲苯在被吡啶中毒的HMDFC-1上的吸附热,并以吸附热的差别区别了两类DFC-1上的酸中心,找出了催化活性随甲苯吸附热的变化曲线。
Dynamic studies on catalysts and catalysis under industrial conditions have drawn much attention. The heat of adsorption reflects the energy status of the catalyst surface and the interaction between the adsorbate molecules and is an important parameter for characterizing the surface properties of the catalyst. There are not many reports on the relationship between the adsorption heat and the catalytic activity of the domestic toluene disproportionation catalyst DFC-1 hydrogen mordenite (HMDFC-1). In the study of the surface acidity of HMDFC-1 by differential thermal absorption method, HMDFC-1 has two kinds of reversible and irreversible adsorption to NH3 under dynamic conditions, but only irreversible adsorption to pyridine. In this paper, the adsorption heats of benzene, toluene and xylene on HMDFC-1, the HM heat of poisoning by NH_3 and the heat of adsorption of toluene on HMDFC-1 poisoned by pyridine were measured by pulse chromatography. Differences between the two types of DFC-1 acid center, find out the catalytic activity with toluene adsorption heat curve.