Synthesis of vinyl acetate on Pd-based catalysts

Kumar, Deepak; Chen, Mingshu; Goodman, D. W.

doi:10.1016/j.cattod.2007.01.050

Cited by 108 publications

(72 citation statements)

References 60 publications

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“…10 For example, dilution of Pd with Au generates materials with exceptional catalytic activity and selectivity in the oxidation of ethylene to vinyl acetate. 11 However, there are exceedingly few studies of bimetallic Au catalysts where Au is the primary active component. Recent studies have examined Au-Cu 12,13 and Au-Ag 14 catalysts for CO and benzyl alcohol oxidation, 15 and Louis' group has reported that trace amounts of Pd enhance the reactivity of Au.…”

Section: Introductionmentioning

confidence: 99%

Enhanced Oxygen Activation over Supported Bimetallic Au−Ni Catalysts

et al. 2010

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New bimetallic Ni-Au supported nanoparticle catalysts were prepared by using dendrimer templated nanoparticles. Amine-terminated generation 5 polyamidoamine (PAMAM) dendrimers were anchored to a commercial silica with a siloxane linked anhydride. The dendrimer was then alkylated and used to template Ni-Au nanoparticles, which were subsequently extracted into organic solution as thiol monolayer protected clusters (MPCs). Transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS) indicated bimetallic nanoparticles of about 2 nm in size. Nanoparticles were deposited onto P-25 TiO 2 , and the capping thiol ligands were removed under flowing H 2 . DRIFTS infrared spectra of adsorbed CO showed only Au on the catalyst surface; no bands attributable to Ni or NiO were observed. Density functional theory (DFT) calculations showed that Au is substantially more stable than Ni on the surface of model slabs. DFT calculations also indicated that the incorporation of Ni into Au slabs results in stronger adsorption of O and CO on Au surfaces. Catalysts were evaluated with low-temperature CO oxidation. Kinetics studies indicated a substantial modification of Au catalysis through Ni incorporation. Apparent activation energies decreased by more than 50% and O 2 reaction orders increased from 0.2 to 0.9. These results are placed in the context of the available literature regarding support effects for Au catalysts. The observed changes to Au chemistry in the current work are substantially larger than previous reports have attributed to support effects. A Michaelis-Menten (enzyme) treatment of the kinetics data indicated that the O 2 reactivity constant increased by a factor of 40 for catalysts with high Ni content. This was in good qualitative agreement with the DFT calculations. At the same time, the introduction of Ni reduced the relative number of catalytically active sites.

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Section: Introductionmentioning

confidence: 99%

Enhanced Oxygen Activation over Supported Bimetallic Au−Ni Catalysts

et al. 2010

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“…Polymers derived from VAM are used in safety glass, film products, and hot-melt adhesives [11]. Although recent work has focused on alternative [12], most VAM is produced by the oxidative addition of acetic acid to ethylene over palladium (Pd) based catalysts [13] as shown in Reaction (1):…”

Section: Open Accessmentioning

confidence: 99%

“…VAM was produced by the oxidative addition of AcOH to ethylene in a continuous packed bed reactor ( Figure 6) containing Pd-Au catalyst supported on silica and promoted by potassium acetate [13]. The system was commissioned and optimized using commercially available non-renewable resources prior to using the system on renewable acetic acid and ethylene.…”

Section: The Production Of Renewable Vam From Acetic Acid Ethylene mentioning

confidence: 99%

The Production of Vinyl Acetate Monomer as a Co-Product from the Non-Catalytic Cracking of Soybean Oil

et al. 2015

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Abstract:Valuable chemical by-products can increase the economic viability of renewable transportation fuel facilities while increasing the sustainability of the chemical and associated industries. A study was performed to demonstrate that commercial quality chemical products could be produced using the non-catalytic cracking of crop oils. Using this decomposition technique generates a significant concentration of C2−C10 fatty acids which can be isolated and purified as saleable co-products along with transportation fuels. A process scheme was developed and replicated in the laboratory to demonstrate this capability. Using this scheme, an acetic acid by-product was isolated and purified then reacted with ethylene derived from renewable ethanol to generate a sample of vinyl acetate monomer. This sample was assessed by a major chemical company and found to be of acceptable quality for commercial production of polyvinyl acetate and other products.

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“…Pd is an active catalyst for the acetoxylation of ethylene to vinyl acetate (VA), see equation (1) [2,3,[24][25][26][27][28][29][30][31][32][33][34][35][36]. However Pd is also an active catalyst for the combustion of ethylene and acetic acid and thus exhibits a low selectivity for VA synthesis (equations (2) and (3) 3) The addition of small amounts of Au to a supported Pd catalysts can significantly enhance its selectivity and activity for this reaction, as shown in Fig.…”

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confidence: 99%

“…However Pd is also an active catalyst for the combustion of ethylene and acetic acid and thus exhibits a low selectivity for VA synthesis (equations (2) and (3) 3) The addition of small amounts of Au to a supported Pd catalysts can significantly enhance its selectivity and activity for this reaction, as shown in Fig. 1 [2,3,[28][29][30][31]. Silica supported Pd-Au bimetallic catalysts promoted with potassium acetate have been used as commercial catalysts for VA synthesis for more than 40 years.…”

mentioning

confidence: 99%