制备条件对铜铬催化剂酸性质的影响

为了研究制备条件对铜铬催化剂酸性质的影响，建立了铜铬催化剂酸性质的检测方法，并采用共沉淀方法研制了不同制备条件的铜铬催化剂，通过SEM 对晶貌的分析得出，催化剂的酸性质与催化剂晶貌有关。通过Thanable假说和Seiyama假说建立了铜铬二元氧化物模型，分析得出，处于无定形状态的铜铬催化剂，其酸中心主要由一元氧化物氧化铜和氧化铬本身带来的，而处于结晶态的铜铬催化剂，其酸中心除了由一元氧化物本身带来的之外，还由于氧化铜和氧化铬混合的不均匀引起的B酸中心的增加。从而表明，铜铬二元氧化物的晶粒越小，晶粒越均匀，催化剂的酸性质越弱，B酸比例越小，相反则越强。

The Effect of Preparation Conditions of Copper Chromite Catalyst on Acid Properties

A series of Cu-Cr catalysts had been synthesized via conventional co-precipitation method under different experimental conditions to investigate the influence of preparation conditions on acidic properties and develop a novel way to detect the acidity .The SEM results show that acidic properties of catalysts have intimate relation with their textural structure . A model of binary CuO/Cr2 O3 mixed oxides had been proposed on the basis of the hypotheses of Thanable and Seiyama .After analysis ,it is indicated that in the amorphous catalysts ,the acidic sites are provided merely by CuO and Cr2 O3 ,while in the crystal samples ,those composed of both the oxides themselves and increasement of B acidic sites caused by the asymmetrical mixture of CuO and Cr2 O3 ,which further illustrated that with the crystal size of oxides decreasing ,the particles became well-distributed ,together with the decreasing of acidic properties of the catalysts and B acid ratio ,and vice versa .