Direct decomposition of nitric oxide on bimetallic catalysts: Effect of metals bonding

Cónsul, Julia Maria Diaz; Peralta, Carlos Alexandre; Ruiz, Juan A.C.; Pastore, Heloise O.; Baibich, Ione Maluf

doi:10.1016/j.cattod.2007.11.035

Cited by 8 publications

(6 citation statements)

References 26 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Vibrational spectroscopy has provided evidence for the adsorption of NO over single crystals and supported catalysts. ,− NO adsorbs on the Pd(111) single crystal in the 1735−1755 cm −1 region as Pd 0 −NO from 150 to 350 K. ,, Pd 0 −NO adsorbs on supported Pd catalysts at 1741−1754 cm −1 between 303 and 673 K during NO−CO reaction. , Pd 0 −NO were observed on Pd/Al 2 O 3 at 1735 cm −1 in the temperature range of 723−823 K during NO decomposition, shown in Figure and . The presence of this species under such a high temperature, indicates that (i) the rate of its conversion (i.e., desorption and decomposition) is not sufficiently high for its depletion and (ii) Pd 0 sites remain on the Pd surface.…”

Section: Discussionmentioning

confidence: 97%

“…Vibrational spectroscopy has provided evidence for the adsorption of NO over single crystals and supported catalysts. 27,[42][43][44][45][46][47] NO adsorbs on the Pd(111) single crystal in the 1735-1755 cm -1 region as Pd 0 -NO from 150 to 350 K. 42,45,46 Pd 0 -NO adsorbs on supported Pd catalysts at 1741-1754 cm -1 between 303 and 673 K during NO-CO reaction. 27,47 Pd 0 -NO were observed on Pd/Al 2 O 3 at 1735 cm -1 in the temperature range of 723-823 K during NO decomposition, shown in Figure 3 and 4.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Pulse Transient Responses of NO Decomposition and Reduction with H₂on Ag−Pd/Al₂O₃

Miller

Chuang

2009

J. Phys. Chem. C

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 97%

Section: Discussionmentioning

confidence: 99%

Pulse Transient Responses of NO Decomposition and Reduction with H₂on Ag−Pd/Al₂O₃

Miller

Chuang

2009

J. Phys. Chem. C

View full text Add to dashboard Cite

“…Most of the catalysts employing noble metals are based on Ru, Rh, Ir, − Pd, − Pt, − Au, − or Ag. − Alloys of these metals diluted into cheaper metals are used aiming at reducing the cost of the catalysts but knowing also that alloying may increase the catalytic performance due to synergic effects caused by the combination of different metals. ,,,,, The support can also have a moderate influence in the activity of the catalyst, as found by Casapu et al after thermal analysis of NO x storage and reduction on Pt/Ba/CeO 2 and Pt/Ba/Al 2 O 3 catalysts. When CeO 2 was used as a support, the catalyst exhibited inferior NO x storage and, particularly, reduction activity when compared with the Al 2 O 3 support.…”

Section: Introductionmentioning

confidence: 99%

The Role of Preadsorbed Atomic Hydrogen in the NO Dissociation on a Zigzag Stepped Gold Surface: A DFT Study

Fajín¹,

Cordeiro²,

Gomes³

2009

J. Phys. Chem. C

View full text Add to dashboard Cite

NO dissociation with and without the presence of hydrogen on the Au(321) surface was investigated using density functional theory and a periodic supercell approach. The role of hydrogen in the reaction of NO dissociation is studied by comparing four different routes (i.e. direct dissociation of NO on the clean surface and paths involving reaction with hydrogen adatoms prior to N-O bond cleavage). In the latter situation, two routes via a NOH intermediate were considered, producing N* + OH* or N* + H 2 O*, and another route via a NHOH intermediate was also considered, yielding NH* and OH* species. The calculations predict that the kinetically most favorable route is that producing nitrogen adatoms and water, i.e., NO* + 2H* f N* + H 2 O* via the NOH* intermediate. This reaction is exothermic (1.1 eV) and the energy barriers for the separate NO* + H* f NOH* and NOH* + H* f N* + H 2 O* reactions are ∼0.5eV. An identical energy barrier was calculated for the reaction of the dissociation of molecular hydrogen on the stepped surface studied here, which is one-half of the barrier calculated in the case of the planar Au(111) surface. The reaction thermodynamically more favorable is that via the NHOH intermediate (1.5 eV). The kinetically least favorable path for NO dissociation on Au(321) is that occurring on the clean surface with an energy barrier of 3.5 eV; this reaction is also highly endothermic (>2.2 eV). The present work shows that the presence of hydrogen is a necessary condition for NO dissociation on this stepped surface.

show abstract

“…Furthermore, other catalysts based on noble metals dispersed on a support were also tested for the NO x elimination 6,7 as those based on Ru, 8 Rh, 9 Ir, [10][11][12] Pd, [13][14][15] Pt, [16][17][18][19][20][21][22] Au, [23][24][25][26] Ag, [27][28][29][30] and also on alloys of these metals with cheaper metals. 8,9,20,22,31,32 In some cases the noble metal was successfully replaced by other elements. [33][34][35][36][37] Two general methods are used for the elimination of the NO x species from the exhaust gas emissions employing solid catalysts, (i) the Selective Catalytic Reduction (SCR) 38 and (ii) the NO x Storage-Reduction (NSR), 39,40 respectively, used for stationary and for non-stationary NO x sources.…”

Section: Introductionmentioning

confidence: 99%

A DFT study of the NO dissociation on gold surfaces doped with transition metals

Fajín

Cordeiro

Gomes

2013

The Journal of Chemical Physics

View full text Add to dashboard Cite

The NO dissociation on a series of doped gold surfaces (type TM n @Au(111) or TM n @Au(110), with TM n = Ni, Ir, Rh, or Ag and referring n to the number of dopant atoms per unit cell) was investigated through periodic density functional theory calculations. Generally, doping of Au (111) and Au(110) matrices was found to strengthen the interaction with NO species, with the exception of Ag, and was found to increase the energy barrier for dissociation, with the exception of Ni on Au(111). The calculations suggest that the NO dissociation is only possible in the case of the Ir@Au(110) bimetallic surface but only at high temperatures. The increase of the contents of Ir on Au(110) was found to improve significantly the catalytic activity of gold towards the NO dissociation (E act = ∼1 eV). Nevertheless, this energy barrier is almost the double of that calculated for NO dissociation on pure Ir(110). However, mixing the two most interesting dopant atoms resulted in a catalyst model of the type Ir@Ni(110) that was found to decrease the energy barrier to values close to those calculated for pure Ir surfaces, i.e., ∼0.4 eV, and at the same time the dissociation reaction became mildly exothermic.

show abstract

Direct decomposition of nitric oxide on bimetallic catalysts: Effect of metals bonding

Cited by 8 publications

References 26 publications

Pulse Transient Responses of NO Decomposition and Reduction with H₂on Ag−Pd/Al₂O₃

Pulse Transient Responses of NO Decomposition and Reduction with H₂on Ag−Pd/Al₂O₃

The Role of Preadsorbed Atomic Hydrogen in the NO Dissociation on a Zigzag Stepped Gold Surface: A DFT Study

A DFT study of the NO dissociation on gold surfaces doped with transition metals

Contact Info

Product

Resources

About

Direct decomposition of nitric oxide on bimetallic catalysts: Effect of metals bonding

Cited by 8 publications

References 26 publications

Pulse Transient Responses of NO Decomposition and Reduction with H2on Ag−Pd/Al2O3

Pulse Transient Responses of NO Decomposition and Reduction with H2on Ag−Pd/Al2O3

The Role of Preadsorbed Atomic Hydrogen in the NO Dissociation on a Zigzag Stepped Gold Surface: A DFT Study

A DFT study of the NO dissociation on gold surfaces doped with transition metals

Contact Info

Product

Resources

About

Pulse Transient Responses of NO Decomposition and Reduction with H₂on Ag−Pd/Al₂O₃

Pulse Transient Responses of NO Decomposition and Reduction with H₂on Ag−Pd/Al₂O₃