title: Design strategies for P-containing fuels adaptable CeO2-MoO3 catalysts for DeNO(x): significance of phosphorus resistance and N2 selectivity.
abstract: Phosphorus compounds from flue gas have a significant deactivation effect on selective catalytic reduction (SCR) DeNOx catalysts. In this work, the effects of phosphorus over three catalysts (CeO2, CeO2-MoO3, and V2O5-MoO3/TiO2) for NH3-SCR were studied, and characterizations were performed aiming at a better understanding of the behavior and poisoning mechanism of phosphorus over SCR catalysts. The CeO2-MoO3 catalyst showed much better catalytic behavior with respect to resistance to phosphorus and N2 selectivity compared with V2O5-MoO3/TiO2 catalyst. With addition of 1.3 wt % P, the SCR activity of V2O5-MoO3/TiO2 decreased dramatically at low temperature due to the impairment of redox property for NO oxidation; meanwhile, the activity over CeO2 and CeO2-MoO3 catalysts was improved. The superior NO oxidation activity contributes to the activity over P-poisoned CeO2 catalyst. The increased surface area and abundant acidity sites contribute to excellent activity over CeO2-MoO3 catalyst. As the content of P increased to 3.9 wt %, the redox cycle over CeO2 catalyst (2CeO2 ↔ Ce2O3 + O*) was destroyed as phosphate accumulated, leading to the decline of SCR activity; whereas, more than 80% NOx conversion and superior N2 selectivity were obtained over CeO2-MoO3 at T > 300 °C. The effect of phosphorus was correlated with the redox properties of SCR catalyst for NH3 and NO oxidation. A spillover effect that phosphate transfers from Ce to Mo in calcination was proposed.
authors.affiliation: State Key Joint Laboratory of Environment Simulation and Pollution Control (SKLESPC), School of Environment, Tsinghua University , Beijing, 100084, China.
authors.forename: Huazhen
authors.initials: H
authors.lastname: Chang
authors.forename: Min Tze
authors.initials: MT
authors.lastname: Jong
authors.forename: Chizhong
authors.initials: C
authors.lastname: Wang
authors.forename: Ruiyang
authors.initials: R
authors.lastname: Qu
authors.forename: Yu
authors.initials: Y
authors.lastname: Du
authors.forename: Junhua
authors.initials: J
authors.lastname: Li
authors.forename: Jiming
authors.initials: J
authors.lastname: Hao
mesh_terms: D000327:Adsorption; D000641:Ammonia / Q000302:isolation & purification; D002384:Catalysis; D002563:Cerium / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry; D058440:Denitrification; D005579:Fossil Fuels / Q000032:analysis*; D008982:Molybdenum / Q000737:chemistry*; D009566:Nitrates / Q000032:analysis; D009569:Nitric Oxide / Q000032:analysis; D009584:Nitrogen / Q000737:chemistry*; D010084:Oxidation-Reduction; D010087:Oxides / Q000737:chemistry*; D010758:Phosphorus / Q000032:analysis*; D017550:Spectroscopy, Fourier Transform Infrared; D013458:Sulfur Dioxide / Q000737:chemistry; D014025:Titanium / Q000737:chemistry; D014867:Water / Q000737:chemistry
chemical_list: D005579:Fossil Fuels; D009566:Nitrates; D010087:Oxides; D014867:Water; D013458:Sulfur Dioxide; C082290:molybdenum trioxide; D010758:Phosphorus; D002563:Cerium; D009569:Nitric Oxide; D003035:Cobalt; C030583:ceric oxide; D000641:Ammonia; D008982:Molybdenum; D014025:Titanium; D009584:Nitrogen