Το work with title Novel doubly-promoted catalysts for the lean NOx reduction by H2 + CO: Pd(K)/Al2O3–(TiO2) by Konsolakis Michail, Vrontaki Maria, Avgouropoulos, George, Ioannides T., Gentekakis Ioannis is licensed under Creative Commons Attribution 4.0 International
Bibliographic Citation
M. Konsolakis, M. Vrontaki, G. Avgouropoulos, T. Ioannides and I. V. Yentekakis, "Novel doubly-promoted catalysts for the lean NOx reduction by H2 + CO: Pd(K)/Al2O3–(TiO2)", Appl. Catal. B, vol. 68, no. 1-2, pp. 59-67, Oct. 2006. doi:10.1016/j.apcatb.2006.07.011
https://doi.org/10.1016/j.apcatb.2006.07.011
The reduction of NO by CO + H2 in the presence of excess O2 has been studied on dispersed, low loading 0.5 wt.% Pd-based catalysts. Two different methods of promotion were imposed separately and together, in order to investigate the feasibility of their synergy to enhance de-NOx efficiency of the catalytic system. Therefore, the Pd-catalysed NO + CO + H2 + O2 reaction was gradually studied over: (i) Pd/Al2O3–(TiO2) catalysts (support-mediated promotion by modifying the Al2O3 support with TiO2), (ii) K-dosed Pd(K)/Al2O3 catalysts (surface-induced promotion by modifying the Pd surface with the addition of K), and (iii) doubly-promoted Pd(K)/Al2O3–(TiO2) catalysts. Both (i) and (ii) methods of promotion were found to significantly promote the system, when acting individually. However, the de-NOx efficiency and N2-selectivity of the doubly-promoted Pd(K)/Al2O3–(TiO2) catalysts were found to be better than both of the other two cases, indicating a synergy during the simultaneous imposition of the two methods of promotion. The resulted benefits with the optimal doubly-promoted catalyst were very high, ∼85%, NOx conversion in a very wide temperature range (100–400 °C), accompanied by very good N2-selectivities of ∼85%, i.e., 15–30 additional percentage units in comparison to the selectivity of the original un-promoted Pd/Al2O3 catalyst.