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以不同温度焙烧TiO(OH)_2得到的TiO_2为载体,采用湿法浸渍法制备RuO_2/TiO_2-C(C=450、550、650及750℃)催化剂,利用XRD、N_2吸附-脱附、TEM和H_2-TPR等表征手段研究催化剂的物理化学性质,并对其在HCl氧化反应中的催化性能进行考察.结果表明:载体焙烧温度对催化剂的结构与活性有显著影响.随着载体焙烧温度(≤650℃)的升高,RuO_2与TiO_2之间的晶面匹配度逐渐变高,促进了RuO_2在TiO_2表面的分散,其中RuO_2/TiO_2-650催化剂表现出最优的催化性能.而当载体焙烧温度过高时,RuO_2/TiO_2-750催化剂的反应活性大大下降,可能是由于过高的焙烧温度导致载体出现严重的烧结团聚现象,以及RuO_2与TiO_2之间过强的相互作用,阻碍了HCl氧化反应的进行.此外,减小RuO_2的粒径可以促进HCl氧化活性的提升.动力学结果显示,催化剂表面的HCl氧化反应主要受O_2分压的影响,表明O_2从催化剂表面的解离吸附为决速步骤.
The catalysts of RuO_2 / TiO_2-C (C = 450, 550, 650 and 750 ℃) were prepared by wet impregnation method using TiO_2 obtained by calcination of TiO (OH) _2 at different temperatures. H_2-TPR and other characterization methods were used to study the physicochemical properties of the catalyst. The catalytic performance of the catalyst in HCl oxidation was investigated. The results showed that the calcination temperature of the catalyst significantly affected the structure and activity of the catalyst.With the calcination temperature ≤650 ℃), the degree of lattice matching between RuO_2 and TiO_2 gradually increased, which promoted the dispersion of RuO_2 on the surface of TiO_2, in which the RuO_2 / TiO_2-650 catalyst showed the best catalytic performance. When the temperature is too high, the reactivity of RuO_2 / TiO_2-750 catalyst decreases greatly, which may be due to the severe agglomeration of the support due to too high calcination temperature and the excessive interaction between RuO_2 and TiO_2, which hinders the oxidation of HCl In addition, reducing the particle size of RuO 2 can promote the improvement of the oxidation activity of HCl.The kinetic results show that the oxidation of HCl on the catalyst surface is mainly affected by the partial pressure of O 2, indicating that the dissociative adsorption of O 2 from the catalyst surface is Rate-determining step.