Cu docking-activated Nb incorporation in multivariate CuO-Nb2O5/CeO2 catalysts for selective reduction of NOx with NH3

Abstract

Improving the low-temperature selective catalytic reduction of NOx with NH3 (NH3-SCR) meanwhile maintaining N2 selectivity are challenging in the field of catalysis. Herein, we showcase the fabrication of the synergistic catalytic sites in the CuO-Nb2O5/CeO2 catalysts. Impressively, the CuO-Nb2O5/CeO2 is characteristic with abundant oxygen vacancies at the interfacial regions, which facilitate the redox reaction between Ce3+, Nb5+ and Cu2+ with the assistance of surface oxygen, exhibiting high NH3-SCR activity, N2 selectivity and wide temperature window at a gas hourly space velocity of 150,000 h−1. Contrast experiments, EXAFS analysis, in situ infrared and Raman spectroscopy, and theoretical calculations indicate that the introduction of proper copper ions in the CeO2 lattice induces the structure distortion of surface CeO2, improving more niobium ions incorporation into the CeO2. The embedded Nb synergizes Cu and Ce to evoke the generation of newly adsorptive sites for NOx and NH3, thus contributing to the NH3-SCR reaction.