The Study Of NO Reaction Properties On Ru And Pt Supported Catalysts

Nitrogen oxides are the main component of atmospheric pollutant s which will lead to environmental problems such as acid rain, photo-chemical smog and so on. NO accounted for more than 90% of the nitrogen oxides, and difficult to be decomposed and removed. In recent years, noble metal catalytic removal of nitrogen oxides has drawn a lot of attention. Our group studied on noble metal catalysts for simultaneous removal of soot and NO, and a systematic investigation found that ruthenium(Ru) and platinum(Pt) have better removal rate. In order to developing more effective NO catalyst, researching of NO reaction on the catalyst is very necessary. Based on the previous work of our group on the study of the reaction of Ru and Pt catalysts, This paper study on NO reaction in oxygen and anaerobic conditions, and the influence of the carrier for the NO reaction, lay the foundation of later research for the storage and reduction of nitrogen oxides.Ru and Pt supported catalysts are prepared by impregnation method. Firstly, we carried on the analysis and characterization of catalysts. The results showed that: Ru/Si O2, Pt/Si O2 and modified catalyst were mesoporous structure, vector modification does not affect the mass transfer of the surface of the catalyst, the carrier type catalyst surface effect of mass transfer. High dispersion state of catalyst surface species is, carrier modification degree has effect on the catalyst surface dispersion, the type of carrier have influence on the surface morphology. Carrier modified reducing effect on the catalyst oxidation mainly noble metal and the modified component interaction.In the fixed bed temperature programmed catalyst in NO system under the condition of oxygen enrichment reaction study. The results showed that: Ru, Pt catalyst has an oxidation reaction, NO and oxygen to generate NO2 NO2 adsorption and decomposition for reduction reactions of N2 and N2 O. The catalytic activity of Ru is better than Pt. The effects of carrier effect, get the best catalyst Ru/Al2O3/Si O2, the Yo=74.39%, To=250 ℃; YR=41.75%, TR=300 ℃. FTIR analysis, Ru/Al2O3/Si O2 activity is better is because part of the conversion of NO to nitrate and nitrite in storage.Study on the catalyst of NO reaction under anaerobic conditions. The results show that: the reaction of basic processes occurring two noble metal catalysts is similar, mainly the NO decomposition to N2 and N2 O reaction, oxygen inhibition phenomenon will occur at high temperature. The catalytic activity of Pt is better than Ru. The effects of carrier effect, get the Pt/Ba O/Si O2 catalyst, the low-temperature activity of the best of its YR=26.13%, TR=300 ℃, at high temperature still exhibits catalytic activity; get the maximum conversion rate of catalyst Pt/Si O2, the YR=63.75%, TR=400 ℃.