Realizing Catalytic Acetophenone Hydrodeoxygenation with Palladium-Equipped Porous Organic Polymers.

Paul R; Shit SC; Fovanna T; Ferri D; Srinivasa Rao B; Gunasooriya GTKK; Dao DQ; Le QV; Shown I; Sherburne MP; Trinh QT; Mondal J

doi:10.1021/acsami.0c16680

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Journal article

Realizing Catalytic Acetophenone Hydrodeoxygenation with Palladium-Equipped Porous Organic Polymers.

Paul R Catalysis & Fine Chemicals Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500007, India.
Shit SC Catalysis & Fine Chemicals Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500007, India.
Fovanna T Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
Ferri D Paul Scherrer Institut, CH-5232 Villigen, Switzerland.
Srinivasa Rao B Academy of Scientific and Innovative Research (AcSIR), Ghaziabad 201002, India.
Gunasooriya GTKK Catalysis Theory Center, Department of Physics, Technical University of Denmark, DK-2800 Lyngby, Denmark.
Dao DQ Institute of Research and Development, Duy Tan University, 03 Quang Trung, Danang 550000, Viet Nam.
Le QV Department of Materials Science and Engineering, Korea University, 145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
Shown I Amrita Centre for Nanosciences and Molecular Medicine, Amrita Institute of Medical Sciences, Amrita Vishwa Vidyapeetham, Kochi 682041, Kerala, India.
Sherburne MP Materials Science and Engineering Department, University of California Berkeley, Berkeley, California 94720, United States.
Trinh QT Institute of Research and Development, Duy Tan University, 03 Quang Trung, Danang 550000, Viet Nam.
Mondal J Catalysis & Fine Chemicals Division, CSIR-Indian Institute of Chemical Technology, Uppal Road, Hyderabad 500007, India.

2020-10-28

Published in:

ACS applied materials & interfaces. - 2020

density functional theory (DFT) calculations

English Porous organic polymers (POPs) constructed through covalent bonds have raised tremendous research interest because of their suitability to develop robust catalysts and their successful production with improved efficiency. In this work, we have designed and explored the properties and catalytic activity of a template-free-constructed, hydroxy (-OH) group-enriched porous organic polymer (Ph-POP) bearing functional Pd nanoparticles (Pd-NPs) by one-pot condensation of phloroglucinol (1,3,5-trihydroxybenzene) and terephthalaldehyde followed by solid-phase reduction with H2. The encapsulated Pd-NPs rested within well-defined POP nanocages and remained undisturbed from aggregation and leaching. This polymer hybrid nanocage Pd@Ph-POP is found to enable efficient liquid-phase hydrodeoxygenation (HDO) of acetophenone (AP) with high selectivity (99%) of ethylbenzene (EB) and better activity than its Pd@Al2O3 counterpart. Our investigation demonstrates a facile, scalable, catalyst-template-free methodology for developing novel porous organic polymer catalysts and next-generation efficient greener chemical processes from platform molecules to produce value-added chemicals. With the aid of comprehensive in situ ATR-IR spectroscopy experiments, it is suggested that EB can be more easily desorbed in a solution, reflecting from the much weaker but better-resolved signal at 1494 cm-1 in Pd@Ph-POP compared to that in Pd@Al2O3, which is the key determining factor in favoring an efficient catalytic mechanism. Density functional theory (DFT) calculations were performed to illustrate the detailed reaction network and explain the high catalytic activity observed for the fabricated Pd@Ph-POP catalyst in the HDO conversion of AP to EB. All of the hydrogenation routes, including direct hydrogenation by surface hydrogen, hydrogen transfer, and the keto-enol pathway, are evaluated, providing insights into the experimental observations. The presence of phenolic hydroxyl groups in the Ph-POP frame structure facilitates the hydrogen-shuttling mechanism for dehydration from the intermediate phenylethanol, which was identified as a crucial step for the formation of the final product ethylbenzene. Besides, weaker binding of the desired product ethylbenzene and lower coverage of surface hydrogen atoms on Pd@Ph-POP both contributed to inhibiting the overhydrogenation reaction and explained well the high yield of EB produced during the HDO conversion of AP on Pd@Ph-POP in this study.

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