Highly Selective Catalytic Reduction of NO by H2over Au0and Au(I) Impregnated in NaY Zeolite Catalysts

Salama, Tarek M.; Ohnishi, Ryuichiro; Shido, Takafumi; Ichikawa, Masaru

doi:10.1006/jcat.1996.0274

Cited by 109 publications

(98 citation statements)

References 0 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Furthermore, it was reported that the NO dissociation is promoted by H ad on platinum [23,24,30±32]. During co-adsorption of NO and CO at 1608C on a Au/NaY catalyst Salama et al did not observe a -NCO band [30]. Only upon introduction of H 2 an intense -NCO developed, indicating the presence of N ad .…”

Section: Kinetics Of the No/h 2 /O 2 Reactionmentioning

confidence: 97%

Kinetics and mechanism of the reduction of nitric oxides by H2 under lean-burn conditions on a Pt–Mo–Co/α-Al2O3 catalyst

Frank

Emig

Renken

1998

Applied Catalysis B: Environmental

127

View full text Add to dashboard Cite

The kinetics and the mechanism of the selective reduction of nitric oxides (NO x ) by hydrogen is studied on a trimetallic Pt± Mo±Co/-Al 2 O 3 catalyst under oxidising conditions. This system is interesting in view of an exhaust gas control of power plants or lean-burn cars. It can be shown that the NO dissociation is the crucial step, dominating the overall reaction behaviour and that it depends on temperature and on the partial pressure of H 2 . With increasing temperatures the reaction reveals an autocatalytic behaviour resulting in bistability and hysteresis. At higher temperatures, where no bistability is found, the NO/H 2 as well as the competing O 2 /H 2 reaction occur only above a certain critical partial pressure of H 2 . The kinetics of the NO/H 2 / O 2 reaction are established using a modi®ed Langmuir±Hinshelwood model (T1428C±1608C, y O2 >4%) which takes into account the critical H 2 partial pressure. The model describes the experimental data within AE15%. The determined activation energies are: 63 kJ/mol for the NO x consumption, 77 and 45 kJ/mol for the N 2 and N 2 O formation, respectively, and 130 kJ/ mol for the O 2 /H 2 reaction. Adsorption enthalpies are determined to À59 kJ/mol for the adsorption of H 2 , À77 kJ/mol for the adsorption of NO and À97 kJ/mol for the adsorption of O 2 . An interesting feature of the reaction is the enhancement of the NO/H 2 reaction by oxygen for low partial pressures of O 2 . This appears to be the ®rst study where a promoting effect of oxygen for the NO/H 2 reaction is found on a platinum supported catalyst. #

show abstract

Section: Kinetics Of the No/h 2 /O 2 Reactionmentioning

confidence: 97%

Kinetics and mechanism of the reduction of nitric oxides by H2 under lean-burn conditions on a Pt–Mo–Co/α-Al2O3 catalyst

Frank

Emig

Renken

1998

Applied Catalysis B: Environmental

127

View full text Add to dashboard Cite

show abstract

“…In agreement with this type of mechanism, Gates and co-workers found that in active CO oxidation gold catalysts on MgO supports, both cationic and neutral gold species were present (517). Other researchers have since lent their support to mechanisms involving the formation of surface formate and the presence of both metallic and oxidic gold (450,456). Bond and Thompson have further speculated that the mechanism may not be the same on all supports (6).…”

Section: 2mentioning

confidence: 99%

Surface chemistry of catalysis by gold

et al. 2004

View full text Add to dashboard Cite

IntroductionGold has long been regarded as an "inert" surface and bulk gold surfaces do not chemisorb many molecules easily. However, in the last decade, largely through the efforts of Masatake Haruta, gold particles, particularly those below 5 nm in size, have begun to garner attention for unique catalytic properties (1-8). In recent years, supported gold particles have been shown to be effective as catalysts for low temperature CO oxidation (9), selective oxidation of propene to propene oxide (10), water gas shift (11), NO reduction (12), selective hydrogenation of acetylene (or butadiene) (13)

show abstract

“…In the last decades one of the most surprising and significant results in the field of catalysis was the finding that nano-structured gold catalysts supported on different metal oxides are highly active at relatively low temperatures in several reactions of technological importance [1][2][3]. Also, it has been established that supported nanosized gold behaves as a catalytically active metal in the NO x reduction by H 2 , CO or hydrocarbons [4][5][6][7][8][9][10]. The low temperature activities of such gold based catalysts make them very promising for DeNO x of the exhaust gases emitted at the start-up of the vehicle's engine (''cold start'' phase).…”

Section: Introductionmentioning

confidence: 99%

NO reduction by CO over gold catalysts based on ceria supports, prepared by mechanochemical activation, modified by Me3+ (Me = Al or lanthanides): Effect of water in the feed gas

Ilieva

Pantaleo

Nedyalkova

et al. 2009

Applied Catalysis B: Environmental

View full text Add to dashboard Cite

show abstract

Highly Selective Catalytic Reduction of NO by H2over Au0and Au(I) Impregnated in NaY Zeolite Catalysts

Cited by 109 publications

References 0 publications

Kinetics and mechanism of the reduction of nitric oxides by H2 under lean-burn conditions on a Pt–Mo–Co/α-Al2O3 catalyst

Kinetics and mechanism of the reduction of nitric oxides by H2 under lean-burn conditions on a Pt–Mo–Co/α-Al2O3 catalyst

Surface chemistry of catalysis by gold

NO reduction by CO over gold catalysts based on ceria supports, prepared by mechanochemical activation, modified by Me3+ (Me = Al or lanthanides): Effect of water in the feed gas

Contact Info

Product

Resources

About