Selective hydrogenation of alkynes over metallic glasses

Molnar, L.

doi:10.1016/0021-9517(86)90229-0

Cited by 47 publications

(8 citation statements)

References 20 publications

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“…This phase was claimed to be responsible for the direct alkyne hydrogenation to alkane (106), while some reports did not find this detrimental effect (18,119). In addition, this phase often can hardly be stable under the reaction conditions: the partial pressure of hydrogen necessary to obtain a stable bPdH phase during the reaction has to be one order of magnitude higher than the equilibrium pressure of hydrogen above the b-PdH phase at the same temperature (116).…”

Section: Nanocatalysis With Controlled Shape and Sizementioning

confidence: 99%

Recent Advances in the Liquid‐Phase Synthesis of Metal Nanostructures with Controlled Shape and Size for Catalysis

2009

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Section: Nanocatalysis With Controlled Shape and Sizementioning

confidence: 99%

Recent Advances in the Liquid‐Phase Synthesis of Metal Nanostructures with Controlled Shape and Size for Catalysis

2009

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“…For example, N-doped polymers as additional modifiers for Lindlar's catalyst gave excellent yields (~98% selectivity at 100% phenylacetylene conversion) [20] . However, Molnar et al [21] found a comparably high selectivity of ~94% at 100% phenylacetylene conversion for an unsupported Pd catalyst without any modification. Kinetic studies of phenylacetylene hydrogenation reveal a zero order kinetics with respect to the alkyne and first order with respect to H 2 [22,23,24] and the apparent activation energies are in the range between 22 and 46 kJ/mol.…”

Section: Introductionmentioning

confidence: 99%

Surface dynamics of the intermetallic catalyst Pd2Ga, Part II – Reactivity and stability in liquid-phase hydrogenation of phenylacetylene

Wowsnick

Teschner

Armbrüster

et al. 2014

Journal of Catalysis

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The catalytic properties of unsupported Pd 2 Ga for the liquid phase hydrogenation of phenylacetylene are investigated after different pre-treatments with focus on the stability of the catalyst during reaction. The surface of as prepared Pd 2 Ga consists mainly on Pd and oxidized Ga species. Under the conditions of the liquid phase hydrogenation of phenylacetylene the intermetallic surface cannot be reformed in situ by reduction of Ga oxide. After a reductive pre-treatment in 5% H 2 /Ar at 400 °C, an almost clean Pd 2 Ga surface can be obtained. Its hydrogenation activity is significantly lowered compared to elemental Pd, which is due to the intrinsic adsorption properties of the intermetallic surface. However, residues of H 2 O or O 2 lead to oxidation of this surface. Excluding these impurities the decomposition can be suppressed. In this case, the bulk material of Pd 2 Ga gets cracked by phenylacetylene during reaction. The controlled modification of the crystal and the electronic structure of Pd by formation of the intermetallic compound Pd 2 Ga is accompanied with a decreased stability.

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“…The classical works of Yamashita et al and Masumoto et al [4][5][6][7][8][9][10][11][12][13][14] on hydrogenation of carbon monoxide motivated rapid growth in research into amorphous alloy catalysis. Various amorphous alloys have been prepared and employed in catalysis including electrolysis [15,16], hydrogenation [4][5][6][7][8][9][17][18][19][20][21][22][23][24][25][26][27][28][29][30][31][32][33][34], hydrogenolysis [8,9], oxidation [35][36][37][38][39], isomerization [28,40], etc. The presence of high concentration of highly coordinatively unsaturated sites on amorphous alloys causes adsorption and surface reactions more easily than on the corresponding crystalline catalysts.…”

Section: Introductionmentioning

confidence: 99%