Adsorbate interactions on a Pt(110) surface. I. Sulfur and carbon monoxide

Abstract. We studied CO adsorption on Pt part icles deposited on well-ordered Fe3O4 (111) thin films grown on Pt(111) by temperature programmed desorption (TPD). A highly stepped Pt(111) surface produced by ion sputter ing and annealing at 600 K was studied for comparison. Structural characterization was performed by scanning tunneling microscopy and Auger electron spectroscopy. The TPD spectra revealed that in addition to the desorption peaks at ~ 400 and ~ 480 K, assigned to CO adsorbed on Pt(111) facets and low -coordination sites respectively, the Pt nanoparticles annealed at 600 K exhibit a desorption state at ~ 270 K.This state is assigned to initial stages of strong metal-support interaction resulting in partial Fe-Pt intermixing. On both Pt/Fe 3 O 4 (111) and stepped Pt(111) surfaces CO is found to dissociate at 500 K. The results suggest that CO dissociation and carbon accumulation occur on the low-coordinated Pt sites.

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“…However, to the best of our knowledge, these two surfaces do not exhibit such a low temperature desorption peak [27][28][29][30][31].…”

Section: Resultsmentioning

confidence: 97%

CO adsorption and dissociation on iron oxide supported Pt particles

et al. 2009

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“…This assumption was tested using the simulation results. With respect to the collision theory, the pre‐exponential factor of a reaction between A and B is defined as:

A^{'} = {((), r_{A} + r_{B})}^{2} {((), \frac{8 π k_{B} T}{μ})}^{0.5},

where r A and r B are the molecular radius of reactants, which participated in collision. The calculated data by density functional theory have been used in this study.…”

Section: Resultsmentioning

confidence: 99%

Kinetic study of hydrogen sulfide decomposition on Pt(111) surface

Mohamadi

Bashiri

2019

Int J of Chemical Kinetics

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In this work, kinetic of H2S conversion to H2 molecule on the surface of Pt(111) is studied using kinetic Monte Carlo simulation. The results of simulation were fitted to the experimental temperature‐programed desorption spectra. The good agreement between the empirical and the simulated data confirms the proposed mechanism and kinetic data (activated energies and pre‐exponential factors). The influence of variables such as temperature and concentrations of H2S and H2 on the overall results of hydrogen production is studied. The condition is proposed in which the best yield of reaction at minimum temperature is obtained. Results show that platinum is a perfect catalyst for converting H2S to H2 and it has a perfect performance (98%) after 5 μs at low temperature of 227°C.

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“…2(b) and Table l), indicating that either the residual poisoning effect of the SHion or the effect of dispersion pH may be the dominant factor (see later). Bonze1 and Ku (13) have shown that pre-adsorbed sulfur affects both the adsorption energy and the total amount of CO adsorbed on Pt(l11) surfaces. In the case of the Pd sol/SH-(0.01 mol dm-3) system, CO treatment of the flocculated sol did not result in sol redispersal and no v(CO),~, was observed in the infrared spectrum of the CO-treated flocculated palladium.…”

Section: Stability Of Hydrosol Towards Added Electrolytesmentioning

confidence: 99%

The effect of added salts on carbon monoxide adsorption on platinum and palladium hydrosols: an FTIR study

Mucalo¹,

Cooney²

1991

Can. J. Chem.

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This paper is dedicated to Professor Richard Norman JonesMICHAEL R. MUCALO and RALPH P. COONEY. Can. J. Chem. 69, 1649 (1991). Fourier transform infrared spectroscopy has been used to investigate the effect of added cations and anions on CO adsorption on platinum and palladium hydrosols. In general, anion effects on CO adsorption may be classified into three categories. 1n the first category, poisoning anions ( e . g . CN-, SH-) block the surface against CO adsorption so that infrared spectra exhibit either no v(CO),~, bands or v(CO),~, bands at lower frequencies (12070 cm-'). In the second category, inert anions ( e . g . the halides, citrate, EDTA~-) have no apparent effect on v(CO),~,. The third category is characterised by anions such as P043-, CO~*-, or stearate ion which affect v(CO),~, via the pH change that the dissolved anions cause in the metal hydrosol dispersion medium. Infrared spectra of platinum and palladium hydrosols in cyanide media were found to exhibit bands due to cyanate, tetracyanoplatinate(II), and tetracyanopalladate(I1) arising from cyanide corrosion of the metal hydrosols. Ultraviolet/visible spectra of iodide ion in platinum hydrosols indicated that iodoplatinate(I1) species had been produced. The band shape of v(CO),~, at 2070 cm-' in platinum hydrosols is found to be s-nsitive to the state of dispersion of the hydrosol particles. Bands due to CO adsorbed on hydrosol particles in either acompletely or partially aggregated state are weaker and broader with a decreased value of v(CO),~, relative to that of the unaggregated hydrosol.

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Adsorbate interactions on a Pt(110) surface. I. Sulfur and carbon monoxide

Cited by 145 publications

References 24 publications

CO adsorption and dissociation on iron oxide supported Pt particles

CO adsorption and dissociation on iron oxide supported Pt particles

Kinetic study of hydrogen sulfide decomposition on Pt(111) surface

The effect of added salts on carbon monoxide adsorption on platinum and palladium hydrosols: an FTIR study

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