CO_2在Cu-Ni/ZrO_2-SiO_2催化剂上的吸附与反应

Chemisorption and Surface Reaction of CO_2 on Cu-Ni/ZrO_2-SiO_2 Catalysts

采用表面反应改性法 ,制备了 Zr O2 - Si O2 (Zr Si O)表面复合物 ;用等体积浸渍法制备了 Zr Si O担载的 Cu-Ni双金属催化剂 .用 IR和 TPD技术 ,研究了 CO2 在其表面上的化学吸附与反应性能 .实验结果表明 ,在 Cu- Ni/Zr Si O催化剂上 CO2 可形成线式吸附态、剪式吸附态和卧式吸附态 ;催化剂表面金属位 M上的剪式吸附态 CO2可与邻近的 lewis酸位 Zrn+作用 ,形成 CO2 卧式吸附态 M- (CO) - O Zr4+ ;该卧式吸附态在一定温度(142℃ )下可解离为 M- CO和 Zr- O- .Zr- O-

The surface complex oxide of ZrO 2 SiO 2(ZrSiO) was prepared by using the surface reaction modification technique. ZrSiO supported Cu Ni bimetallic catalyst was made by the method of isovolumic impregnation. Adsorption states and sites of CO 2 on catalyst were characterized by IR and TPD techniques and the surface reaction mechanism of CO 2 on Cu Ni/ZrSiO was discussed. The results show that CO 2 can be chemisorbed on the surface of catalysts with three types of adsorption states, that is, linear, shearing and horizontal. CO 2 horizontal adsorption state is formed by adsorbed CO 2 in shearing form on the metal site(M) in cooperation with the adjacent Lewis acid site (Zr n + ) and can be dissociated into M-CO and Zr-O - at about 142 ℃. This nascent surface oxygen has good performance in selective oxidation.