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

Research output: Contribution to journal › Article › peer-review

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

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10.1016/j.jcat.2020.11.002

Pischetola_2020_JC_Phenylacetylene_AAM
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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 -