Mechanism of the selective reduction of nitrogen monoxide on platinum-based catalysts in the presence of excess oxygen

Understanding the Role of Hyponitrite in Nitric Oxide Reduction

“…[20][21][22][23][24][25] Many research groups have examined this reaction, and the generally accepted mechanism is thought to involve initial NO dissociation to form surface bound nitride and oxide (Scheme 1a). 18,[24][25][26][27][28][29][30][31] However, more recent experimental work suggests an 4 alternate mechanism could also be operative. In this pathway, NO reduction proceeds via a "hyponitrite-like" (NO) 2 dimer (Scheme 1b), 20,22,[32][33][34] and, in fact, this intermediate has been detected directly with IR spectroscopy on Ag(111) at low temperatures (70 K).…”

Effect of addition of Zn on the catalytic activity of a Co/HZSM-5 catalyst for the SCR of NOx with CH4

“…Reductants such as propane, propene and ethylene have been extensively researched on zeolite-and alumina-supported catalysts [1][2][3][4][5][6][7][8][9]. Use of methane as reducing agent, pioneered by the work of Li and Armor [10], has attracted particular interest, since methane is almost present in all combustion exhausts, particularly in the gas-cogeneration system.…”

Pillared Clays as Superior Catalysts for Selective Catalytic Reduction of Nitric Oxide

“…The oxidized Pt sites are regenerated by reduction with hydrocarbons (e.g., C 3 H 6 ). 8,10,11 However, few studies on SCR on Rh supported catalysts have been reported and the mechanism for NO reduction on Rh catalysts is still unclear. 2,7,12 .…”

“…6 and Pt/ZSM-5, the reaction mechanism has been studied by TAP (temporal analysis of 4 products) and FT-IR techniques. 8,10 It has been generally accepted that the reaction path for reduction of nitric oxide involves a two-step process in which the NO molecules are decomposed to N and O atoms on the reduced platinum sites, then the N atom combines…”

“…[1][2][3][4][5][6][7][8][9] Platinum, iridium, palladium, rhodium and ruthenium supported on Al 2 O 3 , TiO 2 , SiO 2 , ZrO 2 , and ZSM-5 have been studied. [3][4][5][6][7][8] More recently, MCM-41 as a support and ion-exchanged MCM-41 have been studied in our laboratory 9 for the SCR reaction. Both ZSM-5 and MCM-41 have channel-type pores, however, the pores are much bigger in the MCM-41 catalysts, i.e., 0.5-0.…”