The catalytic performance and characterization of ZrO2 support modification on CuO-CeO2/TiO2 catalyst for the simultaneous removal of Hg-0 and NO

摘要

The different addition amounts of ZrO2 on CuO-CeO2/TiO2 catalyst synthesized by co-precipitation method were investigated to research the simultaneous removal of Hg-0 and NO in simulated flue gas. Results indicated that the CuCe/TiZr0.15 catalyst exhibited the superior Hg-0 removal efficiency (72.7%) and prominent NO conversion (83.3%). Hg-0 slightly restrained the NO conversion. Except for the effect of the separate NH3 and NO on Hg-0 removal, significances of the increased NH3/NO ratio on Hg-0 removal and NO conversion were detected. The lower GHSV could give rise to the significant acceleration of Hg-0 and NO removal. With the existence of SO2 and H2O, the slightly prohibitive effect on Hg-0 and NO removal was displayed. BET, XRD, SEM, H-2-TPR, XPS, FTIR analysis were applied to characterize catalysts and the results revealed the ZrO2 modified support on CuO-CeO2/TiO2 resulted in strong redox ability, great mobility of surface oxygen and growing total amount of chemisorbed oxygen and lattice oxygen, which favorably impacted on Hg-0 and NO removal. The introduction of Zr benefited great surface area, weakened crystallinity of TiO2 and then improved the dispersion of metal oxide species. More stable Lewis acid sites to form coordinated NH3 were generated due to ZrO2 additive, The synergetic effect through redox equilibrium of Ce3+ + Cu2+ <-> Ce4+ + Cu+ contributed to Hg-0 removal and NO conversion. In addition, the simultaneous removal of Hg-0 and NO on CuCe/TiZr0.15 in terms of detailed mechanism was discussed. (C) 2016 Elsevier B.V. All rights reserved.