Calorimetric measurement of adsorption and adhesion energies of Cu on Pt(111)

James, Trevor E.; Hemmingson, Stephanie L.; Sellers, Jason R. V.; Campbell, Charles T.

doi:10.1016/j.susc.2016.10.012

Cited by 5 publications

(6 citation statements)

References 47 publications

(77 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A similar drop (19 kJ/mol) was also reported by James et al for Cu adsorption on Pt(111), where the lattice mismatch is larger (Cu is 8% smaller than Pt). That paper provides a detailed explanation of the physical reasons why the heat decreases with increasing 2D island size because of lattice strain. Briefly, as the island size increases, the Au adatoms must sit farther and farther away from the ideal binding site energy minima (which are periodically separated by the Pt(111) lattice distance) because of this lattice mismatch.…”

Section: Discussionsupporting

confidence: 85%

“…The ∼24 kJ/mol drop in adsorption energy from 0.7 to 1 ML in Figures and can be attributed to the lattice mismatch between Au and Pt (Au is 4% larger than Pt in lattice constant) and the resulting buildup of lattice strain within any Au island as well as the strain-induced repulsion between neighboring 2D Au islands . A similar drop (19 kJ/mol) was also reported by James et al for Cu adsorption on Pt(111), where the lattice mismatch is larger (Cu is 8% smaller than Pt). That paper provides a detailed explanation of the physical reasons why the heat decreases with increasing 2D island size because of lattice strain.…”

Section: Discussionsupporting

confidence: 79%

“…The experimental apparatus and methods are essentially identical to those reported in our similar study of the heats of adsorption versus coverage of Cu on Pt(111). 13 Specific differences related to dosing Au rather than Cu can be found in our similar study of Au adsorption energies on thin films of CeO 2 (111) grown on Pt(111). 32 To convert the measured adsorption energies to heats of adsorption requires a small correction to account for the energy difference between the experimental reaction conditions and the reference reaction conditions used here to define "heat of adsorption."…”

Section: Methodsmentioning

confidence: 56%

“…The experimental apparatus and methods are essentially identical to those reported in our similar study of the heats of adsorption versus coverage of Cu on Pt(111) . Specific differences related to dosing Au rather than Cu can be found in our similar study of Au adsorption energies on thin films of CeO 2 (111) grown on Pt(111) …”

Section: Methodsmentioning

confidence: 79%

“…This is because the metals intermix (diffuse into each other) before reaching the desorption temperature. We recently reported the first measurement of the heat of metal adsorption for any such bimetallic system, using single crystal adsorption calorimetry to directly measure the heat of Cu adsorption on Pt(111) at 300 K . Here, we report a similar study of the adsorption energy for the second such system, Au on Pt(111).…”

Section: Introductionmentioning

confidence: 94%

See 4 more Smart Citations

Energetics of Au Adsorption and Film Growth on Pt(111) by Single-Crystal Adsorption Calorimetry

2019

Self Cite

View full text Add to dashboard Cite

Bimetallic catalysts are an important class of heterogeneous catalysts with catalytic properties distinct from either of their bulk metal constituents. The structural, electronic, chemisorptive, and catalytic properties of bimetallic surfaces have been widely studied. Surface reactivity often correlates with adsorption energy of one metal on a singlecrystal surface of the other as measured using temperatureprogrammed desorption (TPD). However, TPD only works for systems where the metals are immiscible. For bimetallic systems that form an alloy or intermetallic compound, TPD generally fails because the adsorbed metal penetrates into the bulk upon heating. The metal-on-metal adsorption energy is unmeasured for all but one such system previously but often calculated because these adlayers often have interesting catalytic properties. We report here calorimetric measurements of the adsorption energy versus coverage of an adlayer of one metal on another for such a bimetallic system, where the metals prefer to alloy: Au on Pt(111). This bimetallic combination is important in catalysis and electrocatalysis. The first monolayer (ML) of Au grows pseudomorphically with the Pt(111) surface at 300 K, with an average heat of adsorption of 389, ∼21 kJ/mol greater than the bulk heat of sublimation of Au. The heat increases with coverage by ∼11 kJ/mol in the first 0.03 ML and then by another ∼2 kJ/mol up to a maximum of 395 kJ/mol at 0.7 ML, and it then decreases to near the bulk heat of sublimation (368 kJ/mol) at 1 ML. The increase in heat is attributed to the increase in size of the two-dimensional Au islands that nucleate at a very low coverage and their corresponding increase in the average number of Au−Au nearest neighbor bonds. The highcoverage decrease in heat is attributed to the buildup of strain associated with the 4% Au/Pt lattice mismatch. The second and possibly third layers of Au show similar but much smaller oscillations in heat around 370 kJ/mol, attributed to the same two effects.

show abstract

Section: Discussionsupporting

confidence: 85%

Section: Discussionsupporting

confidence: 79%

Section: Methodsmentioning

confidence: 56%

Section: Methodsmentioning

confidence: 79%

Section: Introductionmentioning

confidence: 94%

See 3 more Smart Citations

Energetics of Au Adsorption and Film Growth on Pt(111) by Single-Crystal Adsorption Calorimetry

2019

Self Cite

View full text Add to dashboard Cite

show abstract

Interface engineering for a rational design of poison-free bimetallic CO oxidation catalysts

Shin

Zhang

et al. 2017

Nanoscale

View full text Add to dashboard Cite

We use density functional theory calculations of Pt@Cu core@shell nanoparticles (NPs) to design bifunctional poison-free CO oxidation catalysts. By calculating the adsorption chemistry under CO oxidation conditions, we find that the Pt@Cu NPs will be active for CO oxidation with resistance to CO-poisoning. The CO oxidation pathway at the Pt-Cu interface is determined on the Pt NP covered with a full- and partial-shell of Cu. The exposed portion of the Pt core preferentially binds CO and the Cu shell binds O, supplying oxygen for the reaction. The Pt-Cu interface provides CO-oxidation sites that are not poisoned by either CO or O. Additional computational screening shows that this separation of reactant binding sites is possible for several other core@shell NPs. Our results indicate that the metal-metal interface within a single NP can be optimized for design of bifunctional catalytic systems with improved performance.

show abstract

Predicting metal–metal interactions. I. The influence of strain on nanoparticle and metal adlayer stabilities

Streibel

Choksi

Abild‐Pedersen

2020

The Journal of Chemical Physics

View full text Add to dashboard Cite

Strain-engineering of bimetallic nanomaterials is an important design strategy for developing new catalysts. Herein, we introduce an approach for including strain effects into a recently introduced, density functional theory (DFT)-based alloy stability model. The model predicts adsorption site stabilities in nanoparticles and connects these site stabilities with catalytic reactivity and selectivity. Strain-based dependencies will increase the model’s accuracy for nanoparticles affected by finite-size effects. In addition to the stability of small nanoparticles, strain also influences the heat of adsorption of epitaxially grown metal-on-metal adlayers. In this respect, we successfully benchmark the strain-including alloy stability model with previous experimentally determined trends in the heats of adsorption of Au and Cu adlayers on Pt (111). For these systems, our model predicts stronger bimetallic interactions in the first monolayer than monometallic interactions in the second monolayer. We explicitly quantify the interplay between destabilizing strain effects and the energy gained by forming new metal–metal bonds. While tensile strain in the first Cu monolayer significantly destabilizes the adsorption strength, compressive strain in the first Au monolayer has a minimal impact on the heat of adsorption. Hence, this study introduces and, by comparison with previous experiments, validates an efficient DFT-based approach for strain-engineering the stability, and, in turn, the catalytic performance, of active sites in bimetallic alloys with atomic level resolution.

show abstract

Calorimetric measurement of adsorption and adhesion energies of Cu on Pt(111)

Cited by 5 publications

References 47 publications

Energetics of Au Adsorption and Film Growth on Pt(111) by Single-Crystal Adsorption Calorimetry

Energetics of Au Adsorption and Film Growth on Pt(111) by Single-Crystal Adsorption Calorimetry

Interface engineering for a rational design of poison-free bimetallic CO oxidation catalysts

Predicting metal–metal interactions. I. The influence of strain on nanoparticle and metal adlayer stabilities

Contact Info

Product

Resources

About