纳米Ce0.9Cu0.1O2-δ 固溶体的制备、表征和CO低温氧化性能

采用改进的柠檬酸溶胶-凝胶法(即前驱体先在N₂气氛下高温预处理)制备了高比表面积纳米Ce_0.9^Cu_0.1O_2-δ固溶体。采用XRD、TEM和Raman等对催化剂进行表征，并考察了它们的低温CO氧化性能。研究结果表明，改进的柠檬酸溶胶 凝胶法可以制得晶相比较完整的Ce_0.9^Cu_0.1O_2-δ 固溶体，晶粒小于10 nm，明显小于常规方法制得的样品。随着样品焙烧温度的提高，表征氧缺位的600 cm^－1左右Raman峰的位置向高波数方向迁移。采用改进方法制得的Ce_0.9^Cu_0.1O_2-δ 固溶体具有更高的CO氧化活性，其原因归结为晶粒的减小，容易形成氧缺位和表面高分散CuO的增加，从而促进了CO的氧化。

Preparation and characterization of nanostructured Ce0.9Cu0.1O2-δ solid solution and its catalytic property for CO low temperature oxidation

Nanostructured Ce_0.9^Cu_0.1O_2-δ solid solution was prepared by modified citrate sol-gel method (the precursor being pretreated in N₂ at high temperature). The sample was characterized by XRD, TEM, and Raman spectrometry, and its catalytic activity for CO oxidation investigated. It was found that the modified citrate sol-gel method prepared Ce_0.9^Cu_0.1O_2-δ solid solution with ultrafine crystallite size of less than 10 nm, much smaller than that prepared by conventional method. The Raman peak at about 600 cm^-1, attributed to oxygen vacancies, shifted with increasing calcination temperature to higher wavenumber. Solid solution prepared by the modified method exhibited higher catalytic activity for CO low temperature oxidation. This might be attributed to easier formation of oxygen vacancies and increase in finely dispersed CuO species resulting from decrease of the crystalline size.