介孔CuCe/M/CuCe(M=Co,Mn,Zr)催化剂富H_2中优先氧化CO的催化性能

Catalytic properties of mesostructured CuCe/M/CuCe(M = Co,Mn,Zr)catalysts for preferential oxidation of CO in H_2-rich stream

优先氧化是去除富H2中CO最有效的方法,铜铈催化剂是该领域的研究热点。以SBA-15为模板剂,采用纳米刻蚀法合成系列介孔Cu Ce/M/Cu Ce(M=Co,Mn,Zr)催化剂,采用XRD、N2吸附-脱附、TEM、H2-TPR和O2-TPD对催化剂结构及形貌进行表征,并对其在富H2中CO优先氧化性能进行研究。结果表明,Mn有利于催化剂表面吸附氧的增加,有助于大量氧空位的产生,进而促进CO优先氧化性能的提高;Zr的加入抑制了Cu O的还原,且其表面氧脱附温度范围过宽,不利于催化剂催化氧化性能的释放。掺杂Co与Mn可以形成Ce-Cu-M-O固溶体,促进了催化剂表面氧和晶格氧之间的相互转化,最终有利于铜铈催化剂CO优先氧化性能的提高。

The preferential oxidation of CO is an efficient method to reduce the small amount of CO in H2 - rich stream, and CuCe catalysts have been the research hotspots in this field. Using ordered mesoporous silica SBA - 15 as a hard template, mesostructured CuCe/M/CuCe （ M = Co, Mn, Zr） catalysts were synthesized by nano - etching method, and characterized by XRD, N2 adsorption - desorption, TEM, H2 - TPR and O2 - TPD. The catalytic performance of the catalysts for the preferential oxidation of CO in H2 - rich gases was studied. The results indicated that the addition of Mn was beneficial to the increase of surface adsorbed oxygen species and a great deal of oxygen vacancies over CuCe/Mn/CuCe catalyst, and then promoted the improvement of CO preferential oxidation performance. Zr prevented the reduction of CuO,and the desorption temperature range of surface oxygen was too wide to enhance the catalytic performance. When Co and Mn as addtives were doped, the presence of Ce - Cu - M - O solid solution was favorable for the mutual transformation of surface oxygen and lattice oxygen, therefore the CuCe/Mn/CuCe and CuCe/Co/CuCe catalysts presented good catalytic activity.