Ni-Ce-Ti as a superior catalyst for the selective catalytic reduction of NOx with NH3

A novel Ni-Ce-Ti mixed oxide catalyst prepared by the hydrothermal method has been developed for the selective catalytic reduction of NOx by NH3. It was found that Ni-Ce-Ti catalyst showed high NH3-SCR activity, excellent N-2 selectivity with broad operation temperature window. Based on the catalyst characterization, the redox cycle (Ni3+ + Ce3+ <-> Ni2+ + Ce4+), the amorphous structure and more surface defects over Ni-Ce-Ti catalyst are responsible for the high catalytic deNO(x) performance. In situ DRIFT experiments demonstrated that the synergetic effect between Ni and Ce contributes to the formation of reactive NH3 on Lewis acid sites and monodentate nitrate, thus facilitating the NH3-SCR reaction to proceed. The present Ni-Ce-Ti catalyst has great potential for the practical removal of NOx. (C) 2017 Elsevier B.V. All rights reserved.