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Title: Reactivity of Hydrogen on and in Nanostructured Molybdenum Nitride: Crotonaldehyde Hydrogenation

Authors:
; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Argonne National Lab. (ANL), Argonne, IL (United States). Advanced Photon Source (APS)
Sponsoring Org.:
USDOE Office of Science (SC)
OSTI Identifier:
1352240
Resource Type:
Journal Article
Resource Relation:
Journal Name: ACS Catalysis; Journal Volume: 6; Journal Issue: 9
Country of Publication:
United States
Language:
ENGLISH

Citation Formats

Wyvratt, Brian M., Gaudet, Jason R., Pardue, Daniel B., Marton, Andrea, Rudić, Svemir, Mader, Elizabeth A., Cundari, Thomas R., Mayer, James M., and Thompson, Levi T.. Reactivity of Hydrogen on and in Nanostructured Molybdenum Nitride: Crotonaldehyde Hydrogenation. United States: N. p., 2016. Web. doi:10.1021/acscatal.6b00936.
Wyvratt, Brian M., Gaudet, Jason R., Pardue, Daniel B., Marton, Andrea, Rudić, Svemir, Mader, Elizabeth A., Cundari, Thomas R., Mayer, James M., & Thompson, Levi T.. Reactivity of Hydrogen on and in Nanostructured Molybdenum Nitride: Crotonaldehyde Hydrogenation. United States. doi:10.1021/acscatal.6b00936.
Wyvratt, Brian M., Gaudet, Jason R., Pardue, Daniel B., Marton, Andrea, Rudić, Svemir, Mader, Elizabeth A., Cundari, Thomas R., Mayer, James M., and Thompson, Levi T.. 2016. "Reactivity of Hydrogen on and in Nanostructured Molybdenum Nitride: Crotonaldehyde Hydrogenation". United States. doi:10.1021/acscatal.6b00936.
@article{osti_1352240,
title = {Reactivity of Hydrogen on and in Nanostructured Molybdenum Nitride: Crotonaldehyde Hydrogenation},
author = {Wyvratt, Brian M. and Gaudet, Jason R. and Pardue, Daniel B. and Marton, Andrea and Rudić, Svemir and Mader, Elizabeth A. and Cundari, Thomas R. and Mayer, James M. and Thompson, Levi T.},
abstractNote = {},
doi = {10.1021/acscatal.6b00936},
journal = {ACS Catalysis},
number = 9,
volume = 6,
place = {United States},
year = 2016,
month = 9
}
  • A kinetic and DRIFTS (diffuse reflectance FTIR) investigation of crotonaldehyde adsorption and hydrogenation was conducted over TiO{sub 2}-supported Pt and Ni with the intent of gaining insight into the adsorption modes of molecules with carbonyl groups on these catalysts in the SMSI and non-SMSI states. Significant enhancement in selectivity toward crotyl alcohol was observed with each catalyst after reduction at 773 K. DRIFT spectra under reaction conditions identified crotonaldehyde species strongly adsorbed through the C{double_bond}C bond and weakly coordinated through both the C{double_bond}C and the C{double_bond}O bonds on these catalysts after reduction at 573 K, /which gave a peak atmore » 1693 cm{sup {minus}1}. After reduction at 773 K, an additional adsorbed species with a strong band at 1660 cm{sup {minus}1}, indicating a significant interaction between the carbonyl group and the surface, was observed, which is presumed to be stabilized at interfacial Pt-TiO{sub x} and Ni-TiO{sub x} sites. A decrease in the surface coverage of this species paralleled a drop in selectivity to crotyl alcohol with time on stream. After reduction at 573 K, decarbonylation occurred during the initial few minutes on stream to create adsorbed CO on Pt/TiO{sub 2} in addition to carbon deposition, but these reactions were significantly suppressed after reduction at 773 K, presumably due to a TiO{sub x} overlayer which covers part of the Pt surface and breaks up the ensembles of Pt atoms required for these reactions.« less
  • Hydrogenation of crotonaldehyde has been studied over SiO{sub 2}- and TiO{sub 2}-supported Pt catalysts. Over Pt/SiO{sub 2}, the selectivity to the primary products butyraldehyde and crotylalcohol depends critically on the Pt particle size; i.e., the selectivity to the unsaturated alcohol increases with increasing particle size. For large metal particles, the high fraction of Pt(III) surfaces is concluded to favor the adsorption of crotonaldehyde via the carbonyl bond. On small Pt particles, the high abundance of metal atoms in low coordination allows unconstrained adsorption of both double bonds. In this case, the hydrogenation of the C=C bond is kinetically favored. Activitymore » and selectivity of Pt/TiO{sub 2} catalysts after low-temperature reduction are similar to those of Pt/SiO{sub 2}. After high-temperature reduction the selectivity to crotylalcohol is generally enhanced. The selectivity of Pt/TiO{sub 2} catalysts is then determined by the metal particle size and the extent of decoration of Pt with TiO{sub x} particles. The presence of coordinatively unsaturated Ti cations in these oxide particles enhances the sorption strength of the C=O bond resulting in an enhanced selectivity to crotylalcohol. The effects of metal particle size and promotion by TiO{sub x} are additive. TiO{sub x} promotion of catalysts with small particles and the presence of unpromoted large particles allow reaching of selectivities to crotylalcohol of approximately 45%. Promotion of large Pt particles with TiO{sub x} yields 64% selectivity to crotylalcohol. 24 refs., 6 figs., 1 tab.« less
  • The selectivity and activity for the hydrogenation of crotonaldehyde to crotyl alcohol and butyraldehyde was studied over a series of Pt nanoparticles (diameter of 1.7, 2.9, 3.6, and 7.1 nm). The nanoparticles were synthesized by the reduction of chloroplatinic acid by alcohol in the presence of poly(vinylpyrrolidone) (PVP), followed by encapsulation into mesoporous SBA-15 silica. The rate of crotonaldehyde hydrogenation and selectivity towards crotyl alcohol both increase with increasing particle size. The selectivity towards crotyl alcohol increased from 13.7 % to 33.9 % (8 Torr crotonaldehyde, 160 Torr H{sub 2} and 353 K), while the turnover frequency increases from 2.1more » x 10{sup -2} s{sup -1} to 4.8 x 10{sup -2} s{sup -1} with an increase in the particle size from 1.7 nm to 7.1 nm. The decarbonylation pathway to form propene and CO is enhanced over the higher proportion of coordinatively unsaturated sites on the smaller nanoparticles. The apparent activation energy remains constant ({approx} 16 kcal mol{sup -1} for the formation of butyraldehyde and {approx} 8 kcal mol{sup -1} for the formation of crotyl alcohol) as a function of particle size. In the presence of 130-260 mTorr CO, the reaction rate decreases for all products with a CO reaction order of -0.9 for crotyl alcohol and butyraldehyde over 7.1 nm Pt particles; over 1.7 nm Pt particles, the order in CO is -1.4 and -0.9, respectively. Hydrogen reduction at 673 K after calcination in oxygen results in increased activity and selectivity relative to reduction at either higher or lower temperature; this is discussed with regards to the incomplete removal and/or change in morphology of the polymeric surface stabilizing agent, poly(vinylpyrrolidone) used for the synthesis of the Pt nanoparticles.« less
  • Sum-frequency generation vibrational spectroscopy (SFG-VS) and kinetic measurements using gas chromatography have been used to study the surface reaction intermediates during the hydrogenation of three {alpha},{beta}-unsaturated aldehydes, acrolein, crotonaldehyde, and prenal, over Pt(111) at Torr pressures (1 Torr aldehyde, 100 Torr hydrogen) in the temperature range of 295K to 415K. SFG-VS data showed that acrolein has mixed adsorption species of {eta}{sub 2}-di-{sigma}(CC)-trans, {eta}{sub 2}-di-{sigma}(CC)-cis as well as highly coordinated {eta}{sub 3} or {eta}{sub 4} species. Crotonaldehyde adsorbed to Pt(111) as {eta}{sub 2} surface intermediates. SFG-VS during prenal hydrogenation also suggested the presence of the {eta}{sub 2} adsorption species, and becamemore » more highly coordinated as the temperature was raised to 415K, in agreement with its enhanced C=O hydrogenation. The effect of catalyst surface structure was clarified by carrying out the hydrogenation of crotonaldehyde over both Pt(111) and Pt(100) single crystals while acquiring the SFG-VS spectra in situ. Both the kinetics and SFG-VS showed little structure sensitivity. Pt(100) generated more decarbonylation 'cracking' product while Pt(111) had a higher selectivity for the formation of the desired unsaturated alcohol, crotylalcohol.« less
  • Selective hydrogenation of [alpha],[beta]-unsaturated aldehydes into allylic alcohols remains a difficult task to achieve, especially in the gas phase, when working with heterogeneous catalysts. Crotonaldehyde hydrogenation is a complex reaction that has been modeled using results from a standard gas flow system. The obtained results give rise to the formation of a reaction network and an elementary step mechanism derived from steady-state kinetics. The selectivity of the system to give crotyl alcohol is explained in terms of the surface electronic gas model.