NOx selective catalytic reduction at high temperatures with mixed oxides derived from layered double hydroxides

Abstract

ElsevierPalomares Gimeno, AE.; Franch Martí, C.; Ribera, A.; Abellán, G. (2012) Mixed oxides derived from Layered Double Hydroxides (LDHs) have been investigated as potential catalysts for the NO x removal at high temperatures. The best results were obtained with Co-Al mixed oxides derived from LDHs that are active at 750ºC in the presence of oxygen and water. These catalysts could reduce or/and decompose the NO x formed in the dense phase of the FCC regenerator, being deactivated at oxygen concentrations higher than 1.5%.Nevertheless this deactivation is not permanent and they would be regenerated after reduction with hydrogen at 530ºC. The influence of the layered double hydroxides (LDHs) preparation method on the catalyst activity was studied, observing that the activity of the catalyst depends on its chemical composition but it does not depend on the initial LDHs crystallinity, obtaining similar results independently of the synthesis method.

Influence of the degree of infiltration of modified activated carbons with CuO/ZnO on the separation of NO2 at ambient temperatures

“…The conditions with respect to temperature, adsorptive concentration, oxygen concentration, and relative humidity differ considerably to those of the catalytic reduction of NO x in flue gas treatment which is investigated intensively (e.g. Huang et al., 2008; Muniz et al., 1999; Park and Kim, 2005; Palomares et al., 2012). In the last decade, investigations on the adsorption of NO 2 at ambient temperatures (e.g.…”

Effect of precursor synthesis on the physicochemical properties of Zn–Mg–Al mixed oxides

“…Previous works on oxides derived from HT precursors are reported in the literature, and the precursors are produced with both bimetallic and trimetallic layers, such as MgAl (Carvalho et al, 2012;Wang et al, 2012;Feng et al, 2013), ZnAl (Carriazo et al, 2011;Ahmed et al, 2012;Song et al, 2012), CoAl (Palomares et al, 2012) or a series MAl (M 2+ = Co, Ni, Cu, Zn), LaZnAl (Liu et al, 2013), CuZnAl (Cross et al, 2012), NiMgAl (Fang et al, 2014), ZnMgAl (Bezen et al, 2011) or a series MMgAl (M 2+ = Mn, Fe, Co, Ni, Cu and Zn) (Pavel et al, 2012), MMnAl (M 2+ = Ni, Co, Ni-Co, Ni-Cu or Co-Cu) (Kovanda and Jirátová, 2011). The co-precipitation method is the most frequently used in the preparation of these materials.…”

Enhanced Oxygen Vacancies in a Two-Dimensional MnAl-Layered Double Oxide Prepared via Flash Nanoprecipitation Offers High Selective Catalytic Reduction of NOx with NH3

“…For example, two-dimensional (2D) Co-Al MMOs that are derived from LDH have been investigated as a potential catalyst for NO x removal at high temperatures of 750 °C in the presence of oxygen and water [25]. Furthermore, a 2D layered Cu-based catalyst from LDH has been used as an SCR catalyst [26].…”