铜锰铝水滑石的合成、表征及衍生复合氧化物酸碱催化活性研究

Synthesis,characterization and catalysis of Cu-Mn-Al hydrotalcite like compounds

采用低过饱和共沉淀法合成了铜锰铝不同摩尔投料比的碳酸根型水滑石,通过XRD、IR、TG-DTA等手段对样品进行测试和表征。X-衍射结果显示,其M2+/M3+摩尔投料比为2-4得到的水滑石为较满意构型。红外的结果进一步证实了碳酸根离子柱撑CuMnA l水滑石的成功合成,热重-差热分析结果显示随M2+/M3+比的增加,水滑石热稳定性减弱。经焙烧后,发现其复合氧化物催化活性随着Cu含量的增加而增大,随着Mn含量的增加对乙醛的选择性增大,可达到91.6%。

Carbonate pillared hydrotalcite-like compounds （ CuMnAI-HTIcs ） with different Cu/Co/A1 molar raties were synthesized by coprecipitation and characterized by XRD, IR and TG-DTA. The XRD patterns show that the hydrotalcites with M^2＋/M^3＋ molar ratios of 2 to 4 have the good crystal form and high purity. The IR results show that carbonation and hydroxyl are intercalated into the CuMnA1-HTIes interlayer structures. The TG-DTA results show that their thermal stability decreases with the increase of M^2＋/M^3＋ molar ratios in the samples. After calcined, hydrotalcites are converted into composite oxides. The activities of this kind of composite oxides increase with the increase of Cucontent in them. The selectivities to ethanal increase with the increase of Mn content in them. The selectivities to ethanal can reach 91.6%.