The reduction of nitric oxide with carbon monoxide on the Rh(100) single crystal surface

HENDERSHOT, R. E.

doi:10.31274/rtd-180813-11918

Cited by 2 publications

(2 citation statements)

References 23 publications

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“…1 The key step in this process is the dissociative adsorption of NO on the Rh surface, with an activation energy required for the NO bond rupture. 2 As a consequence, the catalysts are in practice used at temperatures exceeding 600 K. At lower temperatures, NO only adsorbs molecularly on the Rh surface. [3][4][5][6] An important topic of research is thus to find a method to enhance catalyst reactivity allowing it to function at lower temperature.…”

Section: Introductionmentioning

confidence: 99%

Tuning the Dissociative Action of Cationic Rh Clusters Toward NO by Substituting a Single Ta Atom

et al. 2019

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The modification of Rh chemical activity for decomposition of NO by alloying with Ta was studied by vibrational spectroscopy of gas phase clusters, where one single Rh atom was substituted by Ta, with NO adsorbed. While NO adsorbs molecularly on pure Rh clusters, it was found to adsorb dissociatively on RhnTa + (n = 2−8) with the O bound to the Ta on-top site. A reaction path for NO decomposition obtained by DFT calculations for octahedral Rh5Ta + and Rh6 + suggests that the Ta oxygen affinity strongly reduces the energy barrier right before bond cleavage, facilitating NO dissociation. The trend is consistent with the Bell-Evans-Polanyi principle. The addition of other, slightly less oxophilic dopant atoms is expected to enhance catalytic reactivity of Rh.

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Section: Introductionmentioning

confidence: 99%

Tuning the Dissociative Action of Cationic Rh Clusters Toward NO by Substituting a Single Ta Atom

et al. 2019

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“…The reaction and interaction between CO and NO on rhodium surfaces is important for automotive exhaust gas catalysis. , Hence, the reaction between NO and CO has extensively been studied on various single crystal surfaces of rhodium: (111), − (100), ,,,, (110), ,,− and (331) . Under steady-state conditions, the reaction between NO and CO proceeds via a generally accepted reaction mechanism, which includes the reversible adsorption of CO and NO, subsequent irreversible decomposition of NO forming nitrogen and oxygen atoms, and the reaction of oxygen with CO to form CO 2 . , Atomic nitrogen recombines to form N 2 at mild pressure conditions, while elevated pressure conditions also lead to recombination with NO to form N 2 O. , NO decomposition and CO 2 formation are surface structure sensitive, with the activity of both reactions on the Rh(100) surface lying in between that of the highly active Rh(110) and least reactive Rh(111) surface…”

Section: Introductionmentioning

confidence: 99%

Interaction and Reaction of Coadsorbed NO and CO on a Rh(100) Single Crystal Surface

et al. 2010

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In order to assess the possibility to follow surface reactions in a quantitative way by vibrational spectroscopy, a combination of temperature programmed reaction spectroscopy (TPRS) and reflection absorption infrared spectroscopy (RAIRS) has been used to study the decomposition of NO and the reaction between NO and CO on Rh(100). NO adsorbs in two configurations: in an almost parallel position at coverages below 0.18 ML and, in addition, in an upright position, probably on a bridge site, at all coverages. Coadsorbing NO and CO has only a minor influence on NO binding, whereas CO shifts gradually from top toward the bridge site under the influence of NO. Combining TP-RAIRS with TPRS during the reaction between CO and NO enabled us to simultaneously study site occupation and obtain qualitative surface coverages and desorption rates. At low surface coverages, NO dissociation is observed at lower temperatures than CO(2) formation. Near saturation, NO dissociation becomes blocked and shifts up in temperature. NO dissociation occurs simultaneously with CO(2) formation. To decompose NO, free surface sites have to be generated through surface diffusion or desorption of some CO. During NO decomposition, the formed oxygen atoms react with CO to form CO(2), creating more empty sites. This may lead to an explosive surface reaction.

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The reduction of nitric oxide with carbon monoxide on the Rh(100) single crystal surface

Cited by 2 publications

References 23 publications

Tuning the Dissociative Action of Cationic Rh Clusters Toward NO by Substituting a Single Ta Atom

Tuning the Dissociative Action of Cationic Rh Clusters Toward NO by Substituting a Single Ta Atom

Interaction and Reaction of Coadsorbed NO and CO on a Rh(100) Single Crystal Surface

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