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有机酸如苯甲酸,水杨酸,邻-或对-苯二甲酸,酒石酸均可在γ-Al_2_3表面自发单层分散,分散的临界温度取决于有机酸分子中极性基团的数目和极性的强弱.XRD,Raman,FT-IR,UV-vis和TG对苯甲酸-γ-Al_2O_3体系的表征结果表明,苯甲酸在室温下即可在γ-Al_2O_3表面自发单层分散;分散后,苯甲酸分子间的氢键缔合结构垮塌;苯甲酸的羧基与γ-Al_2O_3表面羟基发生相互作用并缩水形成类似羧酸盐的结构;分子中的苯环与载体表面没有直接的相互作用.XRD相定量测得的分散阈值为1.1mmol苯甲酸/100m~2γ-Al_2O_3,与按苯环垂直表面计算所得的最大分散容量1.2mmol/100m~2相近.
Organic acids such as benzoic acid, salicylic acid, o- or p-phthalic acid, tartaric acid can all be spontaneously monolayer dispersed on the γ-Al 2 3 surface. The critical temperature of dispersion depends on the number of polar groups in the organic acid molecule and the pole XRD, Raman, FT-IR, UV-vis and TG characterization of the benzoic acid-γ-Al 2 O 3 system show that benzoic acid can be spontaneously monolayer dispersed on the γ-Al 2 O 3 surface at room temperature. , The hydrogen bond association between the benzoic acid molecules collapses. The carboxyl group of benzoic acid interacts with the hydroxyl groups on the γ-Al 2 O 3 surface and shrinks to form a carboxylate-like structure. There is no direct interaction between benzene ring and the surface of the support. The dispersion threshold measured by XRD is 1.1mmol benzoic acid / 100m 2 γ-Al 2 O 3, which is close to the maximum dispersion capacity 1.2mmol / 100m 2 calculated by the vertical surface of benzene ring.