Low-energy electron diffraction, work function charge and mass spectrometric studies of chemisorption and dehydrogenation of cyclohexane, cyclohexene and 1,3-cyclohexadiene on the Pt(111) surface

Gland, John L.; Baron, K.; Somorjai, Gábor A.

doi:10.1016/0021-9517(75)90040-8

Cited by 59 publications

(20 citation statements)

References 6 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Early studies have shown that PtM (M = Pd, Rh, Ir, Sn) nanoparticles can catalyze cyclohexane dehydrogenation as well as other important hydrocarbon conversion reactions. [99][100][101][102][103][104][105] The addition of a second metal component has been shown to result in enhanced selectivity and stability. The superior catalytic performances of bimetallic catalysts in alkane dehydrogenation, when compared to their monometallic counterparts, has raised a considerable interest in bimetallic systems, and has led to the development of industrial systems for the dehydrogenation of light alkanes.…”

Section: St Row Transition Metal Single-site Pdh Catalystsmentioning

confidence: 99%

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Docherty¹,

Rochlitz²,

Payard³

et al. 2021

Chem. Soc. Rev.

View full text Add to dashboard Cite

show abstract

Section: St Row Transition Metal Single-site Pdh Catalystsmentioning

confidence: 99%

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Docherty¹,

Rochlitz²,

Payard³

et al. 2021

Chem. Soc. Rev.

View full text Add to dashboard Cite

show abstract

“…Equation (1) is not necessarily consistent with the work of Gland, et al (1975) who propose that the slow step in cyclohexane dehydrogenation over single Pt crystals is the dehydrogenation of cyclohexene, an intermediate formed at the catalytic surface. Cyclohexene has also been observed over Pt -A1203 catalysts (Smith and Prater, 1967) as well as methyl cyclopentane (Barrett, et al, 1961), but at temperatures, pressures, or hydrogen/hydrocarbon ratios significantly different from the experimental conditions reported here.…”

Section: Analysis Of Kinetic Datamentioning

confidence: 81%

“…The occurrence of methylcyclopentane could arise from the isomerization of cyclchsxcr.a on acid centers to methyl cyclopentene which hydrcgenates to metiiylcyclopentane on the hydro-dehydrogenation centers on the catalyst surface. Cyclohexene is generally believed to be an intermediate in the dehydrogenation of cyclohexane and is often observed experinentally (Gland, 1975;Barnett, et al, 1961;Smith and Prater, 1967) but not always (Maatman, et al, 1971;Basset, et al, 1975;Bridges, 1959). Weisz and Swegler (1955) point out the conditions for detectability of reaction intermediates.…”

Section: Possibilities From the Literaturementioning

confidence: 99%

“…The scheme provided by Mills, which is described in the summ.ary by Sinfelt (1964), for the reforming of C5 hydrocarbons over a bifunctional catalyst is partially revealing: Gland (1975) points out that both cyclohexene and cyclohexadiene have been observed in studies of the dehydrogenation of cyclohexane over Pt field emission tips, Pt-foil and Pt-asbestos catalysts. As the previous reaction scheme demonstrates, the acid cites on our RD-150 catalyst provide the doon\/ay to a variety of simultaneous reactions through the cyclohexene-methylcyclopentane reaction which they support.…”

Section: Possibilities From the Literaturementioning

confidence: 99%

See 1 more Smart Citation

Thermo-chemical energy conversion and storage. Final report

Ritter¹,

DeLancey²,

Schneider³

et al. 1978

View full text Add to dashboard Cite

Thrt book WW propirfld ac an iccoont of work ipooMrad by m i|«ncv of 1h« UnlM Stata GoverfMTwmNeithaf ttia UnitaO Suiat Govarnmant nor anv a^ancv thafaof nor any of thair anwtovaas makaa any warranfy axpraas of impfMd of aMufnw any lagat liability or raaponaibility for tha accuracy coinpiatanaM or uaafulnaaa of any mformatton apoaratus product or pro<«« ditdoaad or repraiants tliat its uM MuU not infrmga priyataly ownad riflhts Rafaranca ftarain to aiTy ipacific rommarciai produa procaat or Mrvica by trada nafna tradamark manufacturar or otharyvna doas not nacaaaarily conatituta or imply its andorsamant laojmmandation of fayorins by tha Umtad States Government or any agency thereof The views and opinions of authors expressed herein do not necessarily state or reflect those of the United Slates Government or any agency thereof There is no obi-cf.on trom the patenl poini of view to the pub'.icatKXi or disseminotJc. ' Nc dccumeat{s| . ibted in ih's lc» . r- We have studied the apparent kinetics of the gas-phase catalytic dehydrogenation of cyclohexane to benzene in an internally recirculated -(gradientless) reactor over the temperature range SOO-BOCF at 1 atm at various space velocities. We have also developed a kinetic model basedon a reversible mass-action rate expression and a catalyst effectiveness factor which is able to correlate both the conversion and reaction rate data very well over the temperature range 500-750''F. The data taken at 800°F appear to be qualitatively and quantitatively different than the data taken at the lower temperatures. It is not as yet clear, whether this can be attributed to a change in kinetic mechanism or some reversible alteration of the catalyst surface at the higher temperature.We have also studied the formation of side products in this system over the same .temperature range. Both the number and amount of side product (s). formed -increases with increasing temperature and residence time. Over the temperature range 500-600"F the side products produced appear to be strongly related to the presence of low molecular weight unsaturated hydrocarbon impurities in our (reagent grade) cyclohexane feed and it is possible that no side products would be formed v/ere it not for the presence of these impurities. At temperatures a-bove SOO^F, both the number and amount of side product(s) produced increases markedly.Finally, we have designed and partially fabricated a test loop which will enable us to study the effects of long term continuous cycling of the system on catalyst activity and side product formation. The size of the loop will also enable us to generate design data for scal.eup of a benzene/cyclohexahe thermochemical energy storage/recovery system and gain operating experience with closed loop chemical energy storage systems deliberately designed to.run in a transient mode.

show abstract

“…Cyclohexane (c-C 6 H 12 ). Cyclohexane adsorption on Pt(111) has been investigated by many groups, ,,,− giving a pretty clear picture of this chemistry. Cyclohexane is H-bonded to the surface with an adsorption energy of about 14 kcal/mol, and about 50% of the chemisorbed monolayer desorbs at 230 K. Dehydrogenation begins at 180−195 K, corresponding to an activation barrier of 13.4 kcal/mol, and takes place via cyclohexene (c-C 6 H 10 ) to form adsorbed benzene.…”

Section: Resultsmentioning

confidence: 99%

Reactivity of Pt and Pt−Sn Alloy Surfaces Probed by Activation of C₅−C₈Cycloalkanes via Electron-Induced Dissociation (EID) of Multilayers

Tsai

Koel

1998

Langmuir

View full text Add to dashboard Cite

The surface chemistry of cycloalkanes and cycloalkyl intermediates on Pt−Sn alloys is important to the function of selective hydrocarbon conversion catalysts, yet very little is known about this chemistry because cycloalkane decomposition is strongly suppressed under UHV conditions on Pt−Sn alloys and there are few other clean sources of these intermediates. Low-energy, electron-induced dissociation (EID) in multilayers of saturated hydrocarbons produces rather cleanly reactive intermediates formed by the selective cleavage of one C−H bond. This method was used to activate C5−C8 cycloalkane multilayers and prepare monolayer coverages of cycloalkyl species on Pt(111) and two well-defined Pt−Sn alloy surfacesthe p(2×2)Sn/Pt(111) and (√3×√3)R30°Sn/Pt(111) surface alloys formed by vapor deposition of Sn on a Pt(111) substrate. EID of the multilayers and subsequent thermal reactions of the intermediates on these surfaces were investigated by temperature-programmed desorption (TPD), Auger electron spectroscopy (AES), and low-energy electron diffraction (LEED). Adsorbed cycloalkyl species dehydrogenate facilely on both alloy surfaces, but alloying with Sn weakens the bonding to the surface of the cycloalkenes formed and strongly suppresses cycloalkene dehydrogenation. This chemistry leads to a much higher selectivity for the evolution of gas-phase cycloalkenes from the dehydrogenation of cycloalkyl intermediates compared to that on Pt(111).

show abstract

Low-energy electron diffraction, work function charge and mass spectrometric studies of chemisorption and dehydrogenation of cyclohexane, cyclohexene and 1,3-cyclohexadiene on the Pt(111) surface

Cited by 59 publications

References 6 publications

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Thermo-chemical energy conversion and storage. Final report

Reactivity of Pt and Pt−Sn Alloy Surfaces Probed by Activation of C₅−C₈Cycloalkanes via Electron-Induced Dissociation (EID) of Multilayers

Contact Info

Product

Resources

About

Low-energy electron diffraction, work function charge and mass spectrometric studies of chemisorption and dehydrogenation of cyclohexane, cyclohexene and 1,3-cyclohexadiene on the Pt(111) surface

Cited by 59 publications

References 6 publications

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Heterogeneous alkane dehydrogenation catalysts investigated via a surface organometallic chemistry approach

Thermo-chemical energy conversion and storage. Final report

Reactivity of Pt and Pt−Sn Alloy Surfaces Probed by Activation of C5−C8Cycloalkanes via Electron-Induced Dissociation (EID) of Multilayers

Contact Info

Product

Resources

About

Reactivity of Pt and Pt−Sn Alloy Surfaces Probed by Activation of C₅−C₈Cycloalkanes via Electron-Induced Dissociation (EID) of Multilayers