钛和锆氧化物载体对钌湿式氧化催化剂性能的影响

Effects of TiO_2,ZrO_2,and Ti_(0.5)Zr_(0.5)O_2 as Supports on Wet Oxidation Performances of Ru Catalyst

以TiO2,ZrO2和Ti0.5Zr0.5O2为载体,采用浸渍法制备了质量分数为1%的Ru贵金属催化剂,利用X射线衍射(XRD)、N2物理吸附(N2BET)、透射电镜(TEM)和程序升温还原(H2-TPR)等表征手段对所制备的贵金属催化剂的物理化学性质进行了表征,并将所制备的催化剂应用于湿式氧化处理模拟有机酸(如丙烯酸、乙酸和丁二酸)废水。结果表明,单一以载体为催化剂处理有机酸废水时,载体的氧化活性由大到小依次为Ti0.5Zr0.5O2>ZrO2>TiO2,而在负载贵金属Ru后催化活性均明显提高,且氧化活性由大到小依次为Ru/TiO2>Ru/Ti0.5Zr0.5O2>Ru/ZrO2。究其原因是TiO2载体比表面大,有利于Ru在其表面高度分散,高分散的Ru进而又促进TiO2晶格氧的流动性,即活性组分与载体间的协同作用有效地提高了Ru/TiO2的氧化活性。以Ru/TiO2为湿式氧化催化剂,在一定反应条件下处理丙烯酸、丁二酸和乙酸废水,化学耗氧量(COD)去除率分别达到94.4%,89.7%和63.1%。

TiO2, ZrO2 and TiO5Zr0.5O2 supported 1%（by mass） Ru catalysts for catalytic wet oxidation （CWO） of waste water containing organic acids （acrylic acid, acetic acid and succinic acid）, were prepared by impregnation method. These catalysts were characterized by X-ray diffraction（XRD）, N2 physical adsorption, H2 temperature-programmed desorption （H2-TPR） and transmission electron microscope （TEM）. The experimental results showed that the CWO activity of supports decreased in sequence： Ti0.5Zr0.5O2〉ZrO2〉TiO2, but the catalytic activity of the above metal oxides could be significantly enhanced by supporting 1% Ru respectively, which decreased in sequence： Ru/TiO2〉Ru/Ti0.5Zr0.502〉Ru/ZrO2. The reason was that Ru could be well dispersed on the surface of TiO2 as support with high specific area, and those highly dispersed Ru part＇icles could simultaneously improve the mobility of TiO2 lattice oxygen. Therefore, the synergism between the active component and support led to the high CWO activity of Ru/TiO2 catalyst. The removal rates of chemical oxygen demand （COD） were 94.4%, 89.7%, and 63.1%, respectively, as treating waste water containing acrylic acid, succinic acid , and acetic acid using Ru/TiO2 as wet oxidation catalyst under certain reaction conditions.