Phenylacetylene hydrogenation coupled with benzyl alcohol dehydrogenation over Cu/CeO2 : a consideration of Cu oxidation state

Chiara Pischetola; Stephen M. Francis; Federico Grillo; Christopher J. Baddeley; Fernando Cárdenas-Lizana

doi:10.1016/j.jcat.2020.11.002

Phenylacetylene hydrogenation coupled with benzyl alcohol dehydrogenation over Cu/CeO₂: a consideration of Cu oxidation state

Chiara Pischetola, Stephen M. Francis, Federico Grillo, Christopher J. Baddeley, Fernando Cárdenas-Lizana

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Abstract

We have examined the effect of copper oxidation state in the continuous gas phase coupled phenylacetylene hydrogenation (to styrene) with benzyl alcohol dehydrogenation (to benzaldehyde) over Cu/CeO₂. Analysis by H₂-TPR, XPS, XRD and STEM-EDX analyses demonstrates the generation of a range of Cu oxidation states (Cu⁰ (13-77%), Cu⁺ (13-74%), Cu2⁺ (0-55%)). The stepwise formation of styrene and ethylbenzene was promoted in the stand-alone phenylacetylene hydrogenation. An increase in Cu⁰/Cu+ (from H₂-TPR and XPS) enhanced H₂ chemisorption and styrene TOF, but with low hydrogen utilisation efficiency. The formation of benzaldehyde and toluene was promoted in the stand-alone dehydrogenation of benzyl alcohol, where benzaldehyde selectivity and TOF correlate with the concentration of Cu⁰. Full hydrogen utilisation, exclusive benzaldehyde/styrene formation and a (3-fold) greater styrene TOF (to attain 100% yield) was achieved in the coupled process, where hydrogenation/dehydrogenation activity correlates with Cu+/Cu⁰. This opens new directions for sustainable “hydrogen free” hydrogenations over non-noble Cu catalysts.

Original language	English
Journal	Journal of Catalysis
Volume	In press
Early online date	13 Nov 2020
DOIs	https://doi.org/10.1016/j.jcat.2020.11.002
Publication status	E-pub ahead of print - 13 Nov 2020

Keywords

Coupling process
phenylacetylene hydrogenation
benzylalcoholdehydrogenation
Copper oxidation sate
Cu/CeO

Access to Document

10.1016/j.jcat.2020.11.002

Pischetola_2020_JC_Phenylacetylene_AAM
Copyright © 2020 Elsevier Inc. All rights reserved. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1016/j.jcat.2020.11.002
Accepted author manuscript, 3.14 MBLicence: CC BY-NC-ND

Cite this

@article{e5b7b01d594f49bb93be2f5a5c76e7d7,

title = "Phenylacetylene hydrogenation coupled with benzyl alcohol dehydrogenation over Cu/CeO2 : a consideration of Cu oxidation state",

abstract = "We have examined the effect of copper oxidation state in the continuous gas phase coupled phenylacetylene hydrogenation (to styrene) with benzyl alcohol dehydrogenation (to benzaldehyde) over Cu/CeO2. Analysis by H2-TPR, XPS, XRD and STEM-EDX analyses demonstrates the generation of a range of Cu oxidation states (Cu0 (13-77%), Cu+ (13-74%), Cu2+ (0-55%)). The stepwise formation of styrene and ethylbenzene was promoted in the stand-alone phenylacetylene hydrogenation. An increase in Cu0/Cu+ (from H2-TPR and XPS) enhanced H2 chemisorption and styrene TOF, but with low hydrogen utilisation efficiency. The formation of benzaldehyde and toluene was promoted in the stand-alone dehydrogenation of benzyl alcohol, where benzaldehyde selectivity and TOF correlate with the concentration of Cu0. Full hydrogen utilisation, exclusive benzaldehyde/styrene formation and a (3-fold) greater styrene TOF (to attain 100% yield) was achieved in the coupled process, where hydrogenation/dehydrogenation activity correlates with Cu+/Cu0. This opens new directions for sustainable “hydrogen free” hydrogenations over non-noble Cu catalysts.",

keywords = "Coupling process, phenylacetylene hydrogenation, benzylalcoholdehydrogenation, Copper oxidation sate, Cu/CeO",

author = "Chiara Pischetola and Francis, {Stephen M.} and Federico Grillo and Baddeley, {Christopher J.} and Fernando C{\'a}rdenas-Lizana",

note = "We shall acknowledge the Engineering and Physical Sciences Research Council, University of Heriot-Watt, and CRITICAT Centre for Doctoral Training for financial support [Ph.D. studentship to Chiara Pischetola; Grant EP/L016419/1].",

year = "2020",

month = nov,

day = "13",

doi = "10.1016/j.jcat.2020.11.002",

language = "English",

volume = "In press",

journal = "Journal of Catalysis",

issn = "0021-9517",

publisher = "Academic Press/Elsevier ",

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TY - JOUR

T1 - Phenylacetylene hydrogenation coupled with benzyl alcohol dehydrogenation over Cu/CeO2

T2 - a consideration of Cu oxidation state

AU - Pischetola, Chiara

AU - Francis, Stephen M.

AU - Grillo, Federico

AU - Baddeley, Christopher J.

AU - Cárdenas-Lizana, Fernando

N1 - We shall acknowledge the Engineering and Physical Sciences Research Council, University of Heriot-Watt, and CRITICAT Centre for Doctoral Training for financial support [Ph.D. studentship to Chiara Pischetola; Grant EP/L016419/1].

PY - 2020/11/13

Y1 - 2020/11/13

N2 - We have examined the effect of copper oxidation state in the continuous gas phase coupled phenylacetylene hydrogenation (to styrene) with benzyl alcohol dehydrogenation (to benzaldehyde) over Cu/CeO2. Analysis by H2-TPR, XPS, XRD and STEM-EDX analyses demonstrates the generation of a range of Cu oxidation states (Cu0 (13-77%), Cu+ (13-74%), Cu2+ (0-55%)). The stepwise formation of styrene and ethylbenzene was promoted in the stand-alone phenylacetylene hydrogenation. An increase in Cu0/Cu+ (from H2-TPR and XPS) enhanced H2 chemisorption and styrene TOF, but with low hydrogen utilisation efficiency. The formation of benzaldehyde and toluene was promoted in the stand-alone dehydrogenation of benzyl alcohol, where benzaldehyde selectivity and TOF correlate with the concentration of Cu0. Full hydrogen utilisation, exclusive benzaldehyde/styrene formation and a (3-fold) greater styrene TOF (to attain 100% yield) was achieved in the coupled process, where hydrogenation/dehydrogenation activity correlates with Cu+/Cu0. This opens new directions for sustainable “hydrogen free” hydrogenations over non-noble Cu catalysts.

AB - We have examined the effect of copper oxidation state in the continuous gas phase coupled phenylacetylene hydrogenation (to styrene) with benzyl alcohol dehydrogenation (to benzaldehyde) over Cu/CeO2. Analysis by H2-TPR, XPS, XRD and STEM-EDX analyses demonstrates the generation of a range of Cu oxidation states (Cu0 (13-77%), Cu+ (13-74%), Cu2+ (0-55%)). The stepwise formation of styrene and ethylbenzene was promoted in the stand-alone phenylacetylene hydrogenation. An increase in Cu0/Cu+ (from H2-TPR and XPS) enhanced H2 chemisorption and styrene TOF, but with low hydrogen utilisation efficiency. The formation of benzaldehyde and toluene was promoted in the stand-alone dehydrogenation of benzyl alcohol, where benzaldehyde selectivity and TOF correlate with the concentration of Cu0. Full hydrogen utilisation, exclusive benzaldehyde/styrene formation and a (3-fold) greater styrene TOF (to attain 100% yield) was achieved in the coupled process, where hydrogenation/dehydrogenation activity correlates with Cu+/Cu0. This opens new directions for sustainable “hydrogen free” hydrogenations over non-noble Cu catalysts.

KW - Coupling process

KW - phenylacetylene hydrogenation

KW - benzylalcoholdehydrogenation

KW - Copper oxidation sate

KW - Cu/CeO

U2 - 10.1016/j.jcat.2020.11.002

DO - 10.1016/j.jcat.2020.11.002

M3 - Article

SN - 0021-9517

VL - In press

JO - Journal of Catalysis

JF - Journal of Catalysis

ER -