载体焙烧温度对RuO_(2)/Al_(2)O_(3)-TiO_(2)催化HCl氧化性能的影响

Effect of calcination temperature of support on catalytic performance of RuO_(2)/Al_(2)O_(3)-TiO_(2) for HCl oxidation

采用共沉淀-机械混合法制备AlTi复合物,经不同温度焙烧,得到Al_(2)O_(3)-TiO_(2)复合载体,采用浸渍法制备RuO_(2)/Al_(2)O_(3)-TiO_(2)催化剂,利用XRD、N_(2)吸附-脱附、CO-TPD和H_(2)-TPR等手段分析催化剂物化性质,并对其催化氧化HCl反应性能进行考察。结果表明,焙烧温度对载体结构及金属Ru分布影响显著,进而影响催化剂活性。焙烧温度的增加,催化剂中金红石相TiO_(2)和α-Al_(2)O_(3)结晶度增加,焙烧温度1100℃制备的RuO_(2)/TiAl-1100催化剂具有大孔径,RuO_(2)和TiO_(2)高晶格匹配度,高金属分散度的特点,催化剂具有较优的HCl转化活性和耐高温活性。

AlTi composites were prepared by co-precipitation-mechanical mixing method,and calcined at different temperatures to obtain Al_(2)O_(3)-TiO_(2) composite carriers.RuO_(2)/AlTi catalysts were prepared by impregnation method.The physicochemical properties of the catalysts were analyzed by the means of XRD,N_(2) adsorption-desorption,CO-TPD and H_(2)-TPR,and their catalytic performance for the oxidation of hydrogen chloride was investigated.The results show that the calcination temperature has a significant effect on the structure of the support and the distribution of metallic Ru,which in turn affects the activity of the catalyst.With the calcination temperature increases,and the crystallinity of rutile TiO_(2) andα-Al_(2)O_(3) in the catalyst increases.At 1100℃,the RuO_(2)/TiAl-1100 catalyst has the characteristics of large pore size,high lattice matching degree of RuO_(2) and TiO_(2),and high metal dispersion,HCl conversion activity and high temperature activity.