화학공학소재연구정보센터
Applied Surface Science, Vol.439, 213-221, 2018
Coupling catalytic hydrolysis and oxidation on Mn/TiO2-Al2O3 for HCN removal
The manganese-modified titania-alumina (Mn/TiO2-Al2O3) catalyst synthesized by sol-gol method was used to remove hydrogen cyanide (HCN) from simulated flue gas. Further, effects of the mass ratios of Ti/Al, Mn loading, calcination temperature, and relative humidity on HCN conversion efficiency and catalytic activity were systematically investigated. The results indicated that the Mn/TiO2-Al2O3 catalyst exhibited significantly enhanced HCN removal efficiency, and the maximum yield of N-2 increased to 68.02% without the participation of water vapor. When water vapor was added into the flue gas, the yield of N-2 decreased and the formation of NOx was also inhibited. The XRD and XPS results indicated that Mn was mainly present in the form of Mn2+, Mn3+, and Mn4+ on the surface of catalyst and chemisorbed oxygen played a major role in the HCN catalytic oxidation process. The results of DSC-TGA analysis and H-2-TPR indicated that the catalyst also exhibited a good thermal and chemical stability. NH3-TPD and CO2-TPD indicated that the surface of the catalyst mainly contained acidic sites. During the reaction, part of NH3 was adsorbed by Bronsted and Lewis acid sites. NH3 adsorbed on Lewis acid sites participated in NH3-SCR, which reduced the amount of NOx produced and resulted in a high N-2 yield. (C) 2018 Elsevier B.V. All rights reserved.