Density functional theory studies of the adsorption of ethylene and oxygen on Pt(111) and Pt3Sn(111)

Watwe, Ramchandra M.; Cortright, Randy D.; Mavrikakis, Manos; Nørskov, Jens K.; Dumesic, James A.

doi:10.1063/1.1346685

Cited by 82 publications

(77 citation statements)

References 78 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Dehydrogenation is a structure insensitive reaction requiring a single active atom [46,47] while hydrogenolysis is a structure sensitive reaction requiring an ensemble of active atoms [47]. It has been shown that Pt 3-fold hollow sites present in large Pt ensembles are responsible for the formation of strongly adsorbed alkylidyne species which are precursors of hydrogenolysis and coke forming reactions [48][49][50][51]. The formation of Pt 3 In reduces the number of Pt 3-fold hollow sites and it has been shown that the formation of ethylidyne is suppressed on Pt 3 Sn alloys with equivalent structures to the Pt 3 In phase in Pt-In(0.7) [48,50,51].…”

Section: Discussionmentioning

confidence: 99%

Structure and reactivity of Pt–In intermetallic alloy nanoparticles: Highly selective catalysts for ethane dehydrogenation

et al. 2018

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

Structure and reactivity of Pt–In intermetallic alloy nanoparticles: Highly selective catalysts for ethane dehydrogenation

et al. 2018

View full text Add to dashboard Cite

“…23 The 2 × 2 two-layer unit cell, containing 6 Pt atoms and 2 Sn atoms, was repeated periodically, with four equivalent layers of vacuum between any two successive metal slabs. Total energy calculations were performed using DACAPO.…”

Section: Methodsmentioning

confidence: 99%

Experimental and DFT Studies of the Conversion of Ethanol and Acetic Acid on PtSn-Based Catalysts

et al. 2004

Self Cite

View full text Add to dashboard Cite

Reaction kinetics studies were conducted for the conversions of ethanol and acetic acid over silica-supported Pt and Pt/Sn catalysts at temperatures from 500 to 600 K. Addition of Sn to Pt catalysts inhibits the decomposition of ethanol to CO, CH 4 , and C 2 H 6 , such that PtSn-based catalysts are active for dehydrogenation of ethanol to acetaldehyde. Furthermore, PtSn-based catalysts are selective for the conversion of acetic acid to ethanol, acetaldehyde, and ethyl acetate, whereas Pt catalysts lead mainly to decomposition products such as CH 4 and CO. These results are interpreted using density functional theory (DFT) calculations for various adsorbed species and transition states on Pt(111) and Pt 3 Sn(111) surfaces. The Pt 3 Sn alloy slab was selected for DFT studies because results from in situ 119 Sn Mössbauer spectroscopy and CO adsorption microcalorimetry of silica-supported Pt/Sn catalysts indicate that Pt-Sn alloy is the major phase present. Accordingly, results from DFT calculations show that transition-state energies for C-O and C-C bond cleavage in ethanolderived species increase by 25-60 kJ/mol on Pt 3 Sn(111) compared to Pt(111), whereas energies of transition states for dehydrogenation reactions increase by only 5-10 kJ/mol. Results from DFT calculations show that transition-state energies for CH 3 CO-OH bond cleavage increase by only 12 kJ/mol on Pt 3 Sn(111) compared to Pt(111). The suppression of C-C bond cleavage in ethanol and acetic acid upon addition of Sn to Pt is also confirmed by microcalorimetric and infrared spectroscopic measurements at 300 K of the interactions of ethanol and acetic acid with Pt and PtSn on a silica support that had been silylated to remove silanol groups.

show abstract

“…In the past, these improvements have been attributed to both geometric as well as electronic effects. [13][14][15][16][17][18][19] Tin atoms on the surface of Pt clusters are known to frustrate the formation of larger active ensembles, which suppresses undesired C-C bond cleavage processes that lead to coke formation and deactivation. 9,[20][21][22][23][24][25][26][27] Careful comparison of catalyst activities at varying residence times reveals an intrinsically higher activity of the alloy compared to pure Pt clusters, 12 indicating the presence of beneficial electronic effects as suggested by theoretical work on metal surfaces.…”

Section: Introductionmentioning

confidence: 99%

Subnanometer-sized Pt/Sn alloy cluster catalysts for the dehydrogenation of linear alkanes

Hauser

Gomes

Bajdich

et al. 2013

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

The reaction pathways for the dehydrogenation of ethane, propane, and butane, over Pt are analyzed using density functional theory (DFT). Pt nanoparticles are represented by a tetrahedral Pt 4 cluster. The objectives of this work were to establish which step is rate limiting and which one controls the selectivity for forming alkenes as opposed to causing further dehydrogenation of adsorbed alkenes to produce precursors responsible for catalyst deactivation due to coking. Further objectives of this work are to identify the role of adsorbed hydrogen, derived from H 2 fed together with the alkane, on the reaction pathway, and the role of replacing one of the four Pt atoms by a Sn atom. A comparison of Gibbs free energies shows that in all cases the rate-determining step is cleavage of a C-H bond upon alkane adsorption. The selectivity to alkene formation versus precursors to coking is dictated by the relative magnitudes of the activation energies for alkene desorption and dehydrogenation of the adsorbed alkene. The presence of an adsorbed H atom on the cluster facilitates alkene desorption relative to dehydrogenation of the adsorbed alkene. Substitution of a Sn atom in the cluster to produce a Pt 3 Sn cluster leads to a downward shift of the potential energy surface for the reaction and causes an increase of the activity of the catalyst as suggested by recent experiments due to the lower net activation barrier for the rate limiting step. However, the introduction of Sn does not alter the relative activation barriers for gas-phase alkene formation versus loss of hydrogen from the adsorbed alkene, the process leading to the formation of coke precursors.

show abstract

Density functional theory studies of the adsorption of ethylene and oxygen on Pt(111) and Pt3Sn(111)

Cited by 82 publications

References 78 publications

Structure and reactivity of Pt–In intermetallic alloy nanoparticles: Highly selective catalysts for ethane dehydrogenation

Structure and reactivity of Pt–In intermetallic alloy nanoparticles: Highly selective catalysts for ethane dehydrogenation

Experimental and DFT Studies of the Conversion of Ethanol and Acetic Acid on PtSn-Based Catalysts

Subnanometer-sized Pt/Sn alloy cluster catalysts for the dehydrogenation of linear alkanes

Contact Info

Product

Resources

About