Removal of nitrogen monoxide through a novel catalytic process. 2. Infrared study on surface reaction of nitrogen monoxide adsorbed on copper ion-exchanged ZSM-5 zeolites

An operando optical fiber UV–vis spectroscopic study of the catalytic decomposition of NO and N2O over Cu-ZSM-5

“…The routes for N 2 O and N 2 formation, as included in step 1 of Scheme 1, are in good agreement with NO decomposition pathways postulated on the basis of infrared and transient reduction and reaction studies [21,33,43]. Nevertheless, we want to stress that the presented UV-vis technique does not offer supporting information for the reaction mechanism of step 1, i.e., the chemisorption of NO and the N-pairing reaction.…”

“…Now, a growing consensus is found that monovalent copper participates in the NO decomposition reaction [27][28][29][30][31][32][33]. A number of experimental and computational studies propose a redox process cycling between Cu(I) and Cu(II)-ELO species (ELO, extralattice oxygen) [27][28][29][30][33][34][35][36][37][38].…”

“…Some studies [27][28][29][30] have suggested that the ELO is associated with mononuclear copper and is of the structure Cu 2+ -O − or Cu 2+ -O 2− . Alternatively, others [21,22,33,[39][40][41] proposed that a single-O-bridged copper pair, i.e., [CuOCu] 2+ , is essential in the NO decomposition cycle. Recent computational contributions of Goodman et al [38,42] stressed the eventual role of double-O-bridged copper pairs, i.e., [CuO 2 Cu] 2+ .…”

On the selectively catalytic reduction of NOx with methane over Ag-ZSM-5 catalysts

“…These dinitrosyl complexes might be a plausible intermediate to produce N 2 O and N 2 , which was evidenced by N 2 O formation accompanying with the decrease of IR bands for dinitrosyl species [35,36]. The desorption of oxygen was not detected in this case, probably because oxygen was strongly bounded on silver surfaces and might be slowly released at high temperatures.…”

Promotional Effect of Titanium on the Catalytic Performance of Anodic Alumina Supported Silver Catalyst for the Selective Reduction of NO with Propene

“…Selective catalytic reduction of nitric oxide with hydrocarbons (SCR of NO with C 3 H 6 ) (Iwamoto et al, 1992) has received a great deal of attention as a possible means of controlling emissions from diesel engines operating under oxygen-rich conditions. In the last decade, Ag-based alumina catalyst was considered one of the most promising de-NO x catalysts, and was extensively investigated using methane (Keshavaraja et al, 2000), propene (Jen, 1998;Meunier et al, 1999Meunier et al, , 2001Martínez-Arias et al, 2000), propane (Angelidis and Kruse, 2001;Satokawa et al, 2001Satokawa et al, , 2003, long paraffins (Shimizu et al, 2000(Shimizu et al, , 2001 and alcohols (Miyadera, 1993;Masuda et al, 1996;Bion et al, 2003) as reductants, due to its relatively high and durable de-NO x activity even in the presence of SO 2 and water, moderate operating temperature window and inexpensive preparation cost.…”