8.16 Heterogeneous Hydrogenation of CC and CC Bonds

Thomas, Stephen P.; Greenhalgh, Mark D.

doi:10.1016/b978-0-08-097742-3.00818-1

Cited by 11 publications

(12 citation statements)

References 246 publications

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“…Alkenes are very important products of the fine chemistry, petrochemistry, and polymer industries, among others. 1,2 Alkenes are produced by non-selective thermal processes (steam cracking) or catalytic cracking of naphtha fractions and are separated into cuts containing predominantly molecules of a specified number of carbon atoms. However, each cut contains multiple unsaturated impurities (alkynes and dienes), so the goal is to purify the alkene stream using solvents (which are not environmentally friendly) or by selective hydrogenation reaction using a catalyst (which is a green-chemistry process).…”

Section: Introductionmentioning

confidence: 99%

Role of the support and chloride during the purification of 1‐pentene in alkyne/alkene streams over Pd catalysts

Cordoba

Betti

Bovier

et al. 2021

J of Chemical Tech & Biotech

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BACKGROUND: Pd nanoparticles over different supports were evaluated during the alkyne selective hydrogenation of medium chain (C 7 and C 5 ) and the 1-pentene purification at mild operational conditions (150 kPa and 303 K). The role of support and chloride was investigated; γ-Al 2 O 3 , γ-Al 2 O 3 modified with Mg, CaCO 3 and activated carbon were used as supports, and PdCl 2 as precursor salt. The classical Lindlar catalyst was used as reference.RESULTS: Surface acidity of supports, active sites dispersion and surface species (MgO, Pd x Cl y O z and/or functional groups) can favor or disfavor the desorption of 1-alkene during the purification of 1-pentene stream. The smallest particle sizes (3.8-10.0 nm) favor the dissociative adsorption of hydrogen over Pd°active sites, promoting good catalytic behavior. The best synthesized catalysts are Pd/Al-Mg and Pd/Ca, and their high selectivity (≥90%) is favored by the presence of superficial acidic Lewis sites. On the contrary, lower selectivity (74-80%) is assessed on catalysts with Brönsted acidic sites (Pd/Al and Pd/RX3) that favored the undesired overhydrogenation or isomerization reactions. CONCLUSION:The geometric and electronic properties of the support have a major influence on the activity and selectivity of the catalysts. Low loaded Pd catalysts supported on Al 2 O 3 -Mg and CaCO 3 (Pd/Al-Mg, Pd/Ca) can be used for the purification of medium or large terminal alkenes at mild reaction conditions as an alternative to the toxic Lindlar commercial catalyst.

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Section: Introductionmentioning

confidence: 99%

Role of the support and chloride during the purification of 1‐pentene in alkyne/alkene streams over Pd catalysts

Cordoba

Betti

Bovier

et al. 2021

J of Chemical Tech & Biotech

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“…Olefins are very important products for the industries of fine chemicals, petrochemicals and polymers 1,2 . Industrial synthesis of alkenes can be carried out by several synthesis routes.…”

Section: Introductionmentioning

confidence: 99%

“…Some of these processes include thermal treatment, dehydrogenation, catalytic cracking and hydrogenation 2,4,5 . After these processes not only desirable products are obtained, undesired products may also be present as alkanes, alkynes or other unsaturated products 6,7 .…”

Section: Introductionmentioning

confidence: 99%

“…Selective hydrogenation is a key process for the elimination of impurities or the obtaining of products with high added value. All selective hydrogenations are of great interest considering economic and ecological aspects 2,8,9 . Selective hydrogenation of alkynes to alkenes represents one of the most important steps in fine chemicals manufacture 10 .…”

Section: Introductionmentioning

confidence: 99%

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Olefin Purification and Selective Hydrogenation of Alkynes with Low Loaded Pd Nanoparticle Catalysts

Cordoba

Coloma

Quiroga

et al. 2019

Ind. Eng. Chem. Res.

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“…9,10 Developed in the 1950s, the heterogeneous Lindlar catalyst (Pd/CaCO 3 /Pb(OAc) 2 /quinoline) 11 still remains a privileged system for Z-selective batch alkyne semihydrogenation. [2][3][4]9 However, it relies on expensive and rare palladium metal, uses toxic Pb additive, and has other limitations such as narrow substrate scope, overhydrogenation to alkanes, Z/E isomerization, and double bond migration reactions of olefin products. Commercial lead-free Pd-based catalysts with increased utilization of palladium were developed only very recently.…”

Section: ■ Introductionmentioning

confidence: 99%

Silica-Supported Cu Nanoparticle Catalysts for Alkyne Semihydrogenation: Effect of Ligands on Rates and Selectivity

et al. 2016

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Narrowly dispersed, silica-supported Cu nanoparticles (ca. 2 nm) prepared via surface organometallic chemistry from a mesityl complex [CuMes] are highly active for the hydrogenation of a broad range of alkynes. High-throughput experimentation allows for identifying the optimal ligand and reaction conditions to turn these supported Cu nanoparticles into highly chemo- and stereoselective catalysts for the preparation of Z-olefins (overall, 23 examples). For instance, PCy-modified Cu nanoparticles semihydrogenate 1-phenyl-1-propyne to cis-β-methylstyrene (20 bar H, 40 °C) with turnover number and turnover frequency of ca. 540 and 1.9 min, respectively, and with 94% selectivity at full conversion.

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8.16 Heterogeneous Hydrogenation of CC and CC Bonds

Cited by 11 publications

References 246 publications

Role of the support and chloride during the purification of 1‐pentene in alkyne/alkene streams over Pd catalysts

Role of the support and chloride during the purification of 1‐pentene in alkyne/alkene streams over Pd catalysts

Olefin Purification and Selective Hydrogenation of Alkynes with Low Loaded Pd Nanoparticle Catalysts

Silica-Supported Cu Nanoparticle Catalysts for Alkyne Semihydrogenation: Effect of Ligands on Rates and Selectivity

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