TiO2纳米管负载Pd催化氯苯加氢脱氯

Catalytic hydrodechlorination of chlorobenzene over Pd supported on TiO_2 Nanotube

以不同温度(250、400、550℃)焙烧的TiO2纳米管(TNT)为载体,分别采用浸渍法和沉淀沉积法制备Pd负载催化剂Pd/TNT,用于研究氯苯气相加氢脱氯反应.采用透射电镜、X射线衍射、N2吸附-脱附、CO化学吸附等表征手段,探讨焙烧温度对载体性质和Pd分散性的影响.表征结果表明,沉淀沉积法比浸渍法制备的催化剂表面Pd粒子的分散性要好,而焙烧温度升高,载体表面羟基含量减少,TiO2纳米管由钛酸转变成锐钛矿结构.表征结果显示,Pd在400℃焙烧的载体上分散性最好,其对氯苯催化加氢脱氯反应的初活性高达92.9%,稳定性最好.

Pd/TiO2 nanotube （TNT） catalysts with TNT calcined at various temperatures were prepared using the deposition-precipitation and impregnation method, and were tested for the gas phase catalytic hydrodechlorination （HDC） of chlorobenzene. The catalysts were characterized by transmission electron microscope （TEM）, X-ray diffraction （XRD）, N2 adsorpfion-desorption, CO chemisorption. The results showed that TNT calcined at 250℃ was dominated by titanate, while TNT calcined at 400℃ and 550℃ mainly consisted of anatase. The content of surface hydroxyl group of TNT decreased with calcination temperature. Catalyst prepared by deposition-precipitation exhibited better Pd dispersion than that prepared by impregnation method. For the catalytic HDC of chlorobenzene, the catalyst with TNT calcined at 400℃ exhibited a much higher activity and stability compared with those calcined at 250℃ and 550℃.