Catalysts For Semihydrogenation Of Alkynes Research Articles

Pd particles decorated 2D-MoSe2 nanomesh as a distinctive catalyst for semihydrogenation of alkynes

The performance of catalysts determines the selectivity and yield of the products in most semihydrogenation of alkynes. Herein, we design a two-dimensional (2D) MoSe2 nanomesh catalyst decorated with Pd particles in the nanopores. The designed 2D-Pd@MoSe2 nanomesh catalyst exhibits 99 % conversion of alkynes and 99 % selectivity in semihydrogenation due to its highly exposed active sites, the higher hydrogenation barrier, and lower desorption energy provided by suitable Pd-Se bond interactions. Further in situ characterizations and density functional theory (DFT) calculations confirm that the Pd@MoSe2 nanomesh has a weaker attraction for alkenes (Edes = 0.36 eV) and the C atoms in alkenes have less negative charges on the Pd@MoSe2 nanomesh surface (−0.139 e), resulting in an increased reaction barrier for alkene overhydrogenation. This research provides new insight for improving the catalytic performance of 2D transition metal dichalcogenides catalysts in the chemical industry.

Lattice Strain and Mott-Schottky Effect of the Charge-Asymmetry Pd1Fe Single-Atom Alloy Catalyst for Semi-Hydrogenation of Alkynes with High Efficiency.

The ideal interface design between the metal and substrate is crucial in determining the overall performance of the alkyne semihydrogenation reaction. Single-atom alloys (SAAs) with isolated dispersed active centers are ideal media for the study of reaction effects. Herein, a charge-asymmetry "armor" SAA (named Pd1Fe SAA@PC), which consists of a Pd1Fe alloy core and a semiconducting P-doped C (PC) shell, is rationally designed as an ideal catalyst for the selective hydrogenation of alkynes with high efficiency. Multiple spectroscopic analyses and density functional theory calculations have demonstrated that Pd1Fe SAA@PC is dual-regulated by lattice tensile and Schottky effects, which govern the selectivity and activity of hydrogenation, respectively. (1) The PC shell layer applied an external traction force causing a 1.2% tensile strain inside the Pd1Fe alloy to increase the reaction selectivity. (2) P doping into the C-shell layer realized a transition from a p-type semiconductor to an n-type semiconductor, thereby forming a unique Schottky junction for advancing alkyne semihydrogenation activity. The dual regulation of lattice strain and the Schottky effect ensures the excellent performance of Pd1Fe SAA@PC in the semihydrogenation reaction of phenylethylene, achieving a conversion rate of 99.9% and a selectivity of 98.9% at 4 min. These well-defined interface modulation strategies offer a practical approach for the rational design and performance optimization of semihydrogenation catalysts.

Mesoporous α-Al2O3-supported PdCu bimetallic nanoparticle catalyst for the selective semi-hydrogenation of alkynes

The selective hydrogenation of alkynes to alkenes is widely applied in the chemical industry; nevertheless, achieving highly selective hydrogenation with high catalytic activity is considerably challenging. Herein, ultrafine PdCu bimetallic nanoparticles encapsulated by high-surface-area mesoporous α-Al2O3 were prepared by high-temperature calcination–reduction using a porous organic framework (POF) as the template. As-obtained PdCu@α-Al2O3 exhibited a high selectivity of 95% for the semi-hydrogenation of phenylacetylene as a probe reaction under mild reaction conditions. The separation of continuous Pd atoms and modification of the Pd electronic state by Cu atoms suppressed β-hydride formation and alkene adsorption, contributing to high selectivity for the catalytic hydrogenation of alkynes. The catalytic activity was maintained after 7 cycles due to the strong interaction between the PdCu bimetallic nanoparticles and α-Al2O3 as well as the encapsulation effect of mesoporous α-Al2O3. Thus, the current work provides a facile strategy for fabricating high-surface-area mesoporous α-Al2O3-supported catalysts for industrial catalysis applications.

In-situ facile synthesis novel N-doped thin graphene layer encapsulated Pd@N/C catalyst for semi-hydrogenation of alkynes

Transition metal-catalyzed semi-hydrogenation of alkynes has become one of the most popular methods for alkene synthesis. Specifically, the noble metal Pd, Rh, and Ru-based heterogeneous catalysts have been widely studied and utilized in both academia and industry. But the supported noble metal catalysts are generally suffering from leaching or aggregation during harsh reaction conditions, which resulting low catalytic reactivity and stability. Herein, we reported the facile synthesis of nitrogen doped graphene encapsulated Pd catalyst and its application in the chemo-selective semi-hydrogenation of alkynes. The graphene layer served as “bulletproof” over the active Pd Nano metal species, which was confirmed by X-ray and TEM analysis, enhanced the catalytic stability during the reaction conditions. The optimized prepared Pd@N/C catalyst showed excellent efficiency in semi-hydrogenation of phenylacetylene and other types of alkynes with un-functionalized or functionalized substituents, including the hydrogenation sensitive functional groups (NO2, ester, and halogen).

A Bidentate Ru(II)-NC Complex as a Catalyst for Semihydrogenation of Alkynes to (E)-Alkenes with Ethanol

Four Ru(II)-NC complexes were tested as catalysts for semihydrogenation of internal alkynes to (E)-alkenes with ethanol, and the complex {(C5H4N)(C6H4)}RuCl(CO)(PPh3)2 (1a) showed the highest activ...

Graphdiyne-based Pd single-atom catalyst for semihydrogenation of alkynes to alkenes with high selectivity and conversion under mild conditions

Pd–GDY catalysts show an evident dependence on Pd species size in hydrogenation reaction. Specifically, Pds–GDY shows superior performance in semihydrogenation of phenylacetylene with much higher TOF of 6290 h−1 and selectivity of 99.3% at 100% conversion.

Pd Nanoparticles and Aminopolymers Confined in Hollow Silica Spheres as Efficient and Reusable Heterogeneous Catalysts for Semihydrogenation of Alkynes

A yolk–shell nanostructured composite composed of Pd nanoparticles (NPs) and aminopolymers, poly(ethylenimine) (PEI), confined in hollow silica spheres which act as an efficient and stable heteroge...

Layered double hydroxide-derived Ni-Cu nanoalloy catalysts for semi-hydrogenation of alkynes: Improvement of selectivity and anti-coking ability via alloying of Ni and Cu

Environmental benign non-noble NiCu catalysts with well-distributed homogeneous nanoalloy structure was fabricated from layered double hydroxide for semi-hydrogenation of acetylene. Compared with monometallic Ni catalyst, the introduction of Cu enhanced ethene selectivity and decreased the deactivation rate in long-term reaction. Furthermore, to give a thorough understanding on structure dependent performance, conventional impregnation was also used to obtain bimetallic NiCu catalyst for comparison. Interestingly, imp-NiCu/MMO presented the mixture of monometallic Ni, Cu and bimetallic NiCu. Catalytic results indicated that 100% conversion was achieved at 160 °C with improved selectivity (>70%) over NiCu nanoalloy catalyst, while bimetallic NiCu catalyst with mixed structure showed both poor conversion (50%) and selectivity (65%). Enhanced activity was attributed to small particle size (3.2 nm) and high metal dispersion (31.4%). Improved selectivity and anti-coking ability were related to the alloying of Ni with Cu, which was conducive to isolate Ni atoms from one another confirmed by STEM-EDX and transfer electron from Cu to Ni certified by XPS. Additionally, superior performance was also found in semi-hydrogenations of hexyne, phenylacetylene, 1,2-diphenylethyne and ethyl phenylpropiolate over NiCu nanoalloy.

Excellent Selectivity with High Conversion in the Semihydrogenation of Alkynes using Palladium‐Based Bimetallic Catalysts

AbstractA series of active‐carbon‐supported PdPb and PdCu bimetal catalysts were prepared for the selective semihydrogenation of alkynes in the liquid phase. The Pd0.33Pb0.67/C catalyst showed the best performance for various alkynes under mild reaction conditions (room temperature and ambient H2 pressure) and achieved 100 % conversion with 98 % selectivity to alkenes. In particular, over‐hydrogenation was avoided at complete alkyne conversion.

Copper(I)–NHC Catalyst for the Stereo-selective Semihydrogenation of Alkynes

Key words alkyne semihydrogenation - Z-stereoselectivity - copper

Intermetallic Nix My (M = Ga and Sn) Nanocrystals: A Non-precious Metal Catalyst for Semi-Hydrogenation of Alkynes.

Intermetallic Nix My (M = Ga and Sn) nanocrystals with uniform particle size and controlled composition are successfully synthesized via a solution-based co-reduction strategy. The as-obtained nanocrystals are crystalline and structurally ordered. The active-site isolation and modified electronic structure are responsible for the excellent catalytic performance for alkyne semi-hydrogenation of the as-obtained non-precious catalysts.

Silica supported palladium phosphine as a robust and recyclable catalyst for semi-hydrogenation of alkynes using syngas

This work reports a chemo-selective semi-hydrogenation of alkynes to alkenes using silica supported palladium phosphine catalyst with syngas (CO/H2). This developed methodology is an alternative to classical Lindlar catalyst for chemo-selective semi-hydrogenation of alkynes to alkenes. Various alkynes were smoothly convert to alkenes in 60–97% conversion with 85–98% selectivity. The prepared catalyst was well characterized by Field Emmission Gun Scanning Electron Microscopy (FEG-SEM), Energy Dispersive X-ray Spectroscopy (EDS), X-ray Photoelectron Spectroscopy (XPS), Inductively Coupled Plasma- Atomic Emmission Spectroscopy (ICP-AES) analysis techniques. In addition, catalyst was effectively recycled up to four consecutive run without significant loss in its catalytic activity and selectivity.

Design of Core-Pd/Shell-Ag Nanocomposite Catalyst for Selective Semihydrogenation of Alkynes

We designed core-Pd/shell-Ag nanocomposite catalyst (Pd@Ag) for highly selective semihydrogenation of alkynes. The construction of the core–shell nanocomposite enables a significant improvement in the low activity of Ag NPs for the selective semihydrogenation of alkynes because hydrogen is supplied from the core-Pd NPs to the shell-Ag NPs in a synergistic manner. Simultaneously, coating the core-Pd NPs with shell-Ag NPs results in efficient suppression of overhydrogenation of alkenes by the Pd NPs. This complementary action of core-Pd and shell-Ag provides high chemoselectivity toward a wide range of alkenes with high Z-selectivity under mild reaction conditions (room temperature and 1 atm H2). Moreover, Pd@Ag can be easily separated from the reaction mixture and is reusable without loss of catalytic activity or selectivity.

Highly efficient and recyclable ruthenium nanoparticle catalyst for semihydrogenation of alkynes

Abstract Ru nanoparticles were used as catalysts for semihydrogenation of alkynes for the first time. Poly(ethylene glycol) (PEG)-stabilized Ru nanoparticles were used as catalysts for semihydrogenation of various terminal alkynes in thermoregulated PEG biphasic system, which allows for not only an efficient homogeneous catalytic reaction, but also an easy biphasic separation and reuse of catalyst. Under the optimized conditions, various terminal alkynes were hydrogenated to the corresponding alkenes with high selectivity. After reaction, the Ru nanoparticle catalyst could be separated from products by simple phase separation and recycled for ten times without evident loss in activity and selectivity.

Nanoporous Gold Catalyst for the Selective Semihydrogenation of Alkynes

Nanoporous Gold Catalyst for the Selective Semihydrogenation of Alkynes

Metal–Ligand Core–Shell Nanocomposite Catalysts for the Selective Semihydrogenation of Alkynes

Catalysts with a sheltered upbringing: Novel core–shell nanocomposite catalysts consisting of active metal nanoparticles encapsulated by macroligands have been prepared. They have Pd nanoparticles (PdNPs) as an active core and shell ligands having sulfoxide moieties coordinated to the PdNPs. The shell protects the catalyst from coordination by alkenes and allows the lead-free selective semihydrogenation of a wide range of alkynes without any additives (see scheme).

Metal–Ligand Core–Shell Nanocomposite Catalysts for the Selective Semihydrogenation of Alkynes

Geschützte Katalyse: Neuartige Kern-Schale-Nanokatalysatoren bestehend aus einem aktiven Palladium-Nanopartikel als Kern und einer Schale aus Sulfoxid-Makroliganden wurden hergestellt. Die Schale schützt den Katalysator vor einer Koordination durch Alkene und ermöglicht die Blei-freie selektive Semihydrierung eines breiten Spektrums von Alkinen ohne jegliche Additive (siehe Schema).

ChemInform Abstract: Palladium on Pumice: New Catalysts for the Stereoselective Semihydrogenation of Alkynes to (Z)‐Alkenes.

AbstractChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a “Full Text” option. The original article is trackable via the “References” option.

Palladium on pumice: new catalysts for the stereoselective semihydrogenation of alkynes to ( Z)-alkenes

High selectivities (93–99%) and excellent stereoselectivities (>99%) in the semihydrogenation of CC triple bonds were achieved using palladium on pumice with a metal loading of 0.5, 1.5 or 3.0% wt as catalyst. The reactions were carried out in ethanol or tetrahydrofuran with only 2.5% of ethylenediamine allowing a self-terminating semihydrogenation independently on the CC triple bond.

Active metals from potassium-graphite. Highly dispersed nickel on graphite as a new catalyst for the stereospecific semihydrogenation of alkynes

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTActive metals from potassium-graphite. Highly dispersed nickel on graphite as a new catalyst for the stereospecific semihydrogenation of alkynesDiego Savoia, Emilio Tagliavini, Claudio Trombini, and Achille Umani-RonchiCite this: J. Org. Chem. 1981, 46, 26, 5340–5343Publication Date (Print):December 1, 1981Publication History Published online1 May 2002Published inissue 1 December 1981https://doi.org/10.1021/jo00339a016RIGHTS & PERMISSIONSArticle Views947Altmetric-Citations48LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (578 KB) Get e-Alerts Get e-Alerts