Catalytic reduction of nitrogen oxide by carbon monoxide, methane and hydrogen over transition metals supported on BEA zeolites

Abstract

Different metals were impregnated onto BEA zeolites supports by ion-exchanging method to prepare catalysts for NO reduction. Activities of the prepared catalysts were then examed in a fixed bed reactor for NO reduction by CO, H2, and CH4. Experimental results indicated that Cu-BEA shows high catalytic activity for NO reduction by CO and H2 at 300 °C–500 °C, while Co-BEA shows high catalytic activity of NO reduction by CH4 at 400 °C–500 °C. Activities of all the catalysts increase as the temperature rises. Then characterization of H2-TPR, XED, XPS and BET were conducted used to investigate the physical and chemical properties of these BEA catalysts. In-situ Fourier transform-infrared spectroscopy was also used to study the mechanism of the reaction of NO reduction by CO, CH4 and H2. The reason of different activities over different BEA catalysts was then carefully explored.