Nanoparticles of Tungsten as Low-Cost Monometallic Catalyst for Selective Hydrogenation of 3-Hexyne

Maccarrone, María Juliana; Lederhos, Cecilia; Betti, Carolina; Carrara, Nicolás; Yori, Juan Carlos; Coloma, Fernando; Liprandi, Domingo; Vera, Carlos Román; Quiroga, Mónica

doi:10.5935/0100-4042.20150170

Cited by 2 publications

(2 citation statements)

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“…10) the values of total conversion as a function of contact time were quite similar for the three catalysts. For the bimetallic co-impregnated and the commercial LD265 catalysts, the total conversion of styrene increase all the contact time, suggesting that no deactivation due to formation of green-oil on the catalysts surface occurred up to 360 min (Maccarrone et al 2016). In these conditions the results indicated that initially the commercial LD265 catalysts was slightly more active than PdNi(1:1), with similar Pd loading, and both were more active than PdNi(1:7) with double palladium content.…”

Section: Semicontinuous Systemmentioning

confidence: 93%

Activity and sulfur resistance of co-impregnated bimetallic PdNi/γ-Al2O3 catalysts during hydrogenation of styrene

Betti

Badano

Lederhos

et al. 2021

Braz. J. Chem. Eng.

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Pyrolysis gasoline (PyGas) is an unstable byproduct of the pyrolysis of naphtha and other hydrocarbons for the production of olefins. PyGas is stabilized by hydrogenation at mild conditions. The hydrogenation of styrene to ethylbenzene is considered a model test reaction for studying the selectivity of the catalysts because it has the slowest rate of conversion. The catalytic activity and selectivity of two bimetallic coimpregnated Pd-Ni catalysts supported on γ-alumina were assessed and compared to those of a commercial monometallic Pd catalyst (AXENS LD265). The laboratory-prepared catalysts had different metal content and Pd:Ni atomic ratios (1:1 and 1:7). Catalytic tests of selective hydrogenation of styrene to ethylbenzene were made in a batch stirred tank reactor and in a continuous fixed bed trickle bed reactor. The sulfur resistance of the bimetallic catalysts in semicontinuous condition, was assessed by means of the same operational conditions using thiophene as a model poison compound. The support, Pd-Ni coimpregnated catalysts and LD265 commercial catalysts were further characterized by N 2 chemisorption,

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Section: Semicontinuous Systemmentioning

confidence: 93%

Activity and sulfur resistance of co-impregnated bimetallic PdNi/γ-Al2O3 catalysts during hydrogenation of styrene

Betti

Badano

Lederhos

et al. 2021

Braz. J. Chem. Eng.

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show abstract

“…However, their activity is far lower than precious metals, and thus, they have been ignored in the past decades. Nowadays, metal oxides are becoming attractive as hydrogenation catalysts. − For example, CeO 2 is reported to exhibit good activity for the selective hydrogenation of acetylenic compounds and nitroaromatics, and nanoscale Co 3 O 4 and Fe 2 O 3 are reported to be very active and selective for the hydrogenation of nitroarenes under mild conditions. − …”

Section: Introductionmentioning

confidence: 99%

Structure and Activity Transition from Oxidized to Metallic Tungsten for Catalytic Hydrogenation: A Density Functional Theory Study

et al. 2018

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Oxide-based hydrogenation catalysts have attracted intensive interest, but the relationships between their composition, structure, and reaction mechanism are still ambiguous. Here, we conducted density functional theory (DFT) calculation on ethylene hydrogenation over WO 3 , WO 2.72 , WO 2 , and W catalysts to explore how the structure and catalytic activity change with the composition and explain why neither WO 3 nor metallic W is a good hydrogenation catalyst but WO 3−x is. Calculations on the geometric and electronic structures show a transition from semiconductor to metal-like with more W−W metal bonds appearing from the corresponding oxidized to metallic tungsten. Correspondingly, the H 2 dissociation mechanism changes from heterotypic on the semiconductor WO 3 and WO 2.72 to homotypic on the metal-like WO 2 and metallic W, and the adsorption strength of the dissociation product (2H) enhances from oxidized to metallic W. Calculations on the stepwise hydrogenation indicate that H 2 dissociation is the rate-limiting step (RLS) for WO 3 and WO 2.72 , whereas the following hydrogenation step (C 2 H 5 + H → C 2 H 6 ) is the RLS for WO 2 and W. By linear fitting the binding energies of H 2 , 2H, H + C 2 H 5 , and C 2 H 6 adsorptions, a perfect correlation between (H + C 2 H 5 ) and (2H) adsorptions is observed; thus, the catalytic activity and mechanism can be evaluated using 2H adsorption behavior as the descriptor. On the basis of the calculation results, we predict that the best ethylene hydrogenation activity will show at 2 < x < 2.72 for WO x . This work suggests that controlling the composition between the stoichiometric oxide and the metal may be an effective way to develop an active hydrogenation catalyst.

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Nanoparticles of Tungsten as Low-Cost Monometallic Catalyst for Selective Hydrogenation of 3-Hexyne

Cited by 2 publications

References 1 publication

Activity and sulfur resistance of co-impregnated bimetallic PdNi/γ-Al2O3 catalysts during hydrogenation of styrene

Activity and sulfur resistance of co-impregnated bimetallic PdNi/γ-Al2O3 catalysts during hydrogenation of styrene

Structure and Activity Transition from Oxidized to Metallic Tungsten for Catalytic Hydrogenation: A Density Functional Theory Study

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