Computational Insights into the Role of Metal and Acid Sites in Bifunctional Metal/Zeolite Catalysts: A Case Study of Acetone Hydrogenation to 2-Propanol and Subsequent Dehydration to Propene

Konda, Sai Sriharsha M.; Caratzoulas, Stavros; Vlachos, Dionisios G.

doi:10.1021/acscatal.5b01686

Cited by 55 publications

(45 citation statements)

References 67 publications

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“…In the former case, the first hydrogen atom would attack the O end of C=O group, producing the hydroxyl intermediate, while in the latter case, C end of C=O group would be hydrogenated first, leading to the formation of alkoxy intermediate. It has been reported previously that hydroxyl intermediate was thermodynamically less favorable than alkoxy intermediate 33 , 34 . On both surfaces, the hydrogenation of DMO begins with the nucleophilic attack of H δ− to the electron deficient carbon of ester group.…”

Section: Resultsmentioning

confidence: 87%

Interfacing with silica boosts the catalysis of copper

et al. 2018

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Metal-support interaction is one of the most important parameters in controlling the catalysis of supported metal catalysts. Silica, a widely used oxide support, has been rarely reported as an effective support to create active metal-support interfaces for promoting catalysis. In this work, by coating Cu microparticles with mesoporous SiO2, we discover that Cu/SiO2 interface creates an exceptional effect to promote catalytic hydrogenation of esters. Both computational and experimental studies reveal that Cu–Hδ− and SiO–Hδ+ species would be formed at the Cu–O–SiOx interface upon H2 dissociation, thus promoting the ester hydrogenation by stablizing the transition states. Based on the proposed catalytic mechanism, encapsulting copper phyllosilicate nanotubes with mesoporous silica followed by hydrogen reduction is developed as an effective method to create a practical Cu nanocatalyst with abundant Cu-O-SiOx interfaces. The catalyst exhibits the best performance in the hydrogenation of dimethyl oxalate to ethylene glycol among all reported Cu catalysts.

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Section: Resultsmentioning

confidence: 87%

Interfacing with silica boosts the catalysis of copper

et al. 2018

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“…Note that the E1 mechanism was also found to be unfavorable in the case of isopropanol dehydration in HZSM-5. [33] Concerted E2 mechanisms were then further investigated. Thea ctivation enthalpies calculated for each of the acidic sites are reported in Table 2.…”

Section: Zuschriftenmentioning

confidence: 99%

Isopropanol Dehydration on Amorphous Silica–Alumina: Synergy of Brønsted and Lewis Acidities at Pseudo‐Bridging Silanols

et al. 2016

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The mechanism of isopropanol dehydration on amorphous silica-alumina (ASA) was unraveled by ac ombination of experimental kinetic measurements and periodic density functional theory (DFT) calculations.W es how that pseudo-bridging silanols (PBS-Al) are the most likely active sites owingt ot he synergy between the Brønsted and Lewis acidic properties of these sites,which facilitates the activation of alcohol hydroxy groups as leaving groups.I sopropanol dehydration was used to specifically investigate these PBS-Al sites,whose density was estimated to be about 10 À1 site nm À2 on the silica-doped alumina surface under investigation, by combining information from experiments and theoretical calculations.

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“…The

W

value decreased with an increase in the reaction temperature. One of the reasons could be the hydrogenation‐dehydration of acetone, as it was shown for the cases with Ni/zeolite [37] and Ni/SiO 2 [38] catalysts. In particular, Sooknoi et al [38] .…”

Section: Resultsmentioning

confidence: 93%

Thermal behavior of Mg−Ni‐phyllosilicate nanoscrolls and performance of the resulting composites in hexene‐1 and acetone hydrogenation

et al. 2020

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Here we report on the thermal properties of Mg−Ni‐phyllosilicate nanoscrolls as a promising precursor for production of Ni/silicate composite catalysts. Spontaneous scrolling of the phyllosilicate layer originating from size difference between metal‐oxygen and silica sheets provides high surface area of the catalyst. Metal nanoparticles can be obtained directly from the matrix by H2 reduction. The phyllosilicate structure passed through a number of transformations including partial dehydroxylation with formation of sepiolite‐like phase followed by silicate or oxide crystallization. Temperature ranges of these transitions overlapped with the reduction process sophisticating the H2 consumption profiles. In particular, some amount of Ni2+ got sealed up by the sepiolite structural features, that opened a path for the tuning of Ni0 : Ni2+ ratio of the catalyst. An increase of Ni content in the system yielded a decrease in the metal nanoparticles sizes due to both high intensity of nucleation and type of residual matrix. Ni nanoparticles size distribution and specific surface area of the composite catalysts governed conversion rate of hexene‐1 and acetone hydrogenation. In the view of the turnover frequency MgNi2Si2O5(OH)4 precursors were slightly more preferable than pure Ni3Si2O5(OH)4.

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Computational Insights into the Role of Metal and Acid Sites in Bifunctional Metal/Zeolite Catalysts: A Case Study of Acetone Hydrogenation to 2-Propanol and Subsequent Dehydration to Propene

Cited by 55 publications

References 67 publications

Interfacing with silica boosts the catalysis of copper

Interfacing with silica boosts the catalysis of copper

Isopropanol Dehydration on Amorphous Silica–Alumina: Synergy of Brønsted and Lewis Acidities at Pseudo‐Bridging Silanols

Thermal behavior of Mg−Ni‐phyllosilicate nanoscrolls and performance of the resulting composites in hexene‐1 and acetone hydrogenation

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