Synthesis Of Cerium-zirconium Solid Solution And Their Catalytic Performance For Carbon Monoxide Oxidation

With the development of society and economy, increasing vehicle emissions, as poor oxygen and incomplete oxidation lead to more and more CO was produced such as hydrocarbon of carbon-containing compounds. In addition, in cigarette combustion produces a large number of compounds, carbon monoxide (CO) is a kind of great risk to human health in the gases, for it is very urgent to eliminate CO.Cerium-zirconium solid solution with good oxygen storage properties and thermal stability, in fuel cells, catalytic combustion of methane, a chlorine-containing VOCs catalytic purification, motor vehicle exhaust catalytic purification and other fields have a very important role. Oxygen storage properties and redox properties of cerium-zirconium solid solution is closely related to the factors such as its Oxygen vacancy concentration, the mobility of oxygen vacancies, surface area and the forming of anion defects. In order to further improve the oxidation ability of cerium zirconium solid solution catalytic, in many research methods, the preparation of cerium zirconium solid solution is the most crucial.This paper studies application of two methods to prepare cerium zirconium solid solution. One is a kind of improved citric acid method and the other is a biological template method. In the process of preparation of mesoporous materials, the bio-templated preparation method has been the focus of preparation. Extensive source of renewable biological templates, unique structure, easy to remove, and so on, received a lot of attention. This paper first time to use of tobacco waste (mainly tobacco leaves and stems) and the tobacco stem silk as biological templates to successfully prepared cerium-zirconium solid solution. And using N2adsorption-desorption, scanning electron microscope (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD), photoelectron spectroscopy (XPS), temperature programmed reduction (H2-TPR), oxygen storage (OSC) and CO oxidation activity evaluation to characterize and test the materials. Experimental studies have shown that:CO oxidation activity of Cerium-zirconium solid solution which was prepared with citric acid decreased with the increase of Zr contented, because of the CO oxidation activity of ZrO2is very poor. The reduce of active species CeO2cause the decrease of CO oxidation activity.Using tobacco waste articles (mainly tobacco leaves and stems) for biological templates, cerium zirconium solid solution was successfully achieved. Experimental studies showed that CO oxidation activity of cerium-zirconium solid solution using tobacco leaves as template prepared is not high, but with a high oxygen storage capacity (OSC), reached1976μmol/g. And CO oxidation activity of cerium zirconia solid solution prepared with stem template is high than cerium-zirconium solid solution prepared with tobacco leaves template, but the oxygen storage capacity is much lower.The CO oxidation activity of cerium zirconium solid solution prepared by tobacco silk as biological template with different ratio of cerium zirconium is different, especially for the1:1ratio of the cerium zirconium solid solution shows high activity. Its CO light-off temperature is153℃, which is higher than the literature reported in the CO oxidation activity of cerium zirconium solid solution.