Research on SCR of NO with CO over the Cu0.1La0.1Ce0.8O mixed-oxide catalysts: Effect of the grinding

In this work, the mixed oxide catalysts Cu0.1La0.1Ce0.8O with the different grinding time (denoted as x, x = 0,1, 5, 10, 15, or 20) for low-temperature selective catalytic reduction (SCR) of NO with CO are prepared by the grinding method. XRD, SEM, BET, XPS, in situ DRIFTS, H-2-TPR, and O-2-TPD measurements are used to characterize the catalysts CLC xh, which is objective to illuminate the influence of the grinding on the physicochemical and catalytic properties of CLC xh composite materials and understand the reaction mechanism of the CO-SCR catalytic process. The results show that CLC 10 h exhibited the highest catalytic performance, well water-resistance capacity and excellent catalytic stability for NO reduction by CO model reaction, because more catalytic domains (SSOV, Cu-square-Ce (La) species) can generate in the reaction process due to the enhancement of redox behavior with Cu-O-Ce (La) active species, and more active sites are able to form in the grinding process. Undoubtedly, the high concentration of Cu+ is beneficial to NO adsorption and the doping of La enhanced the N-2 selectivity of the catalysts significantly. Combined with the in situ DRIFTS results, a possible catalytic reaction mechanism is tentatively proposed to discuss the NO + CO model reaction. (C) 2016 Elsevier B.V. All rights reserved.