Preparation Of CuO-ceO₂ Composite Oxide And Its Performance Of Catalytic Reduction Of No By Co

In this paper,the copper-cerium composite metal oxide catalyst was prepared by simple grinding method and template method and applied to catalytic reduction of NO by CO,the effects of different preparation methods on the catalytic performance of copper-cerium composite metal oxide catalyst were investigated.Firstly,two-phase coexisting Cu O-Ce O₂catalyst were prepared by simple grinding method to explore the coexisting effect and the influence of different proportions of Cu/Ce on the structure and catalytic performance of the catalysts.All samples were characterized by X-ray powder diffraction（XRD）,High resolution transmission electron microscope（HRTEM）,N₂adsorption-desorption,Raman spectra,H₂-temperature programmed reduction（H₂-TPR）,X-ray photoelectron spectroscopy（XPS）,In situ diffuse reflectance infrared fourier transform spectra（in situ FT-IR）and so on.It is found that the Cu⁺in the catalyst plays an important role in the catalytic reaction,it is not only related to the active site where the NO molecule dissociates,but Cu⁺-CO combines with oxygen species,which can increase CO adsorption sites and oxygen vacancies.Secondly,under the premise of using porous organic polymer as a template,exploring the effects of Cu O-Ce O₂catalysts prepared under different conditions on the catalytic performance,structure,and dispersion state,aiming to explore the structural properties of the catalyst with the best catalytic activity.At the same time,the same proportion of Cu O-Ce O₂catalyst was prepared by grinding method,and it was found that the catalyst obtained by template method has good low-temperature activity due to its loose porous structure.The catalyst Cu Ce-A-DA-20-500 had the best catalytic activity,indicating that the preparation conditions of the catalyst are the best,which is reflected in that it has the most surface oxygen species and the best redox performance.Finally,using the porous organic polymer as a template,using the optimal preparation conditions obtained above,and the effect of different molar ratios on the Cu O-Ce O₂catalyst was explored.It was found that the Cu_0.3Ce_0.7catalyst had the best catalytic performance,this is due to the uniform dispersion and strong interaction between Cu O and Ce O₂,and the synergistic effect of the Cu²⁺+Ce³⁺（？）Cu⁺+Ce⁴⁺reaction.In addition,the bulk Cu_0.3Ce_0.7catalyst was prepared,and it was found that the addition of the template can increase the specific surface area and reduction ability of the catalyst.It was found that the activity of bulk Cu_0.3Ce_0.7was significantly lower than that of the Cu_0.3Ce_0.7catalyst,indicating that the template could be beneficial improving the catalytic performance of the catalyst.The possible reaction mechanisms of Cu_0.3Ce_0.7and bulk Cu_0.3Ce_0.7are similar,but the CO is more easily adsorbed on the catalyst Cu_0.3Ce_0.7to form carbonate species,which is beneficial to the progress of the reaction.