Journal of Catalysis, Vol.369, 190-200, 2019
Rational construction of direct Z-scheme doped perovskite/palygorskite nanocatalyst for photo-SCR removal of NO: Insight into the effect of Ce incorporation
V-Ti oxide catalyst has been widely employed in selective catalytic reduction (SCR) of NOx in industry. However, considerable cost and high reaction temperatures are commonly required. Alternatively, photo-SCR working at low temperature has attracted widespread interest. In the present work, Pr1-xCexFeO3/palygorskite (Pal) nanocomposite was synthesized by an in situ sol-gel method. Results indicate that Pr1-xCexFeO3 remain as a perovskite solid solution uniformly immobilized on the surface of Pal when x is less than 0.05. CeO2 co-precipitates with Pr1-xCexFeO3 when x is beyond 0.05, leading to an enhanced charge separation induced by the formation of intimate direct Z-scheme heterostructure of Pr1-xCexFeO3/CeO2, which is unraveled by the photoluminescence spectroscopy and Mott-Schottky analysis and further verified by the DFT calculations. Under visible light irradiation, the influence of the doping amount of Ce (from 0.05 to 0.5) on the NO conversion and N-2 selectivity was investigated. The Pr0.7Ce0.3FeO3/Pal was found to achieve the highest NO conversion rate of 92% and 99% N-2 selectivity. In addition, the SO2 and H2O resistance experiment show that the doping of Ce could benefit the formation of cerium sulphate which prevents NH3 from being sulfated by SO2 while Pal prevents the catalysts from being corroded by H2O, respectively. (C) 2018 Elsevier Inc. All rights reserved.