Acetylene Semi-Hydrogenation at Room Temperature over Pd−Zn Nanocatalyst

Tiwari, G and Sharma, G and Verma, R and Gakhad, P and Singh, AK and Polshettiwar, V and Jagirdar, BR (2023) Acetylene Semi-Hydrogenation at Room Temperature over Pd−Zn Nanocatalyst. In: Chemistry - A European Journal, 29 (63).

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Abstract

A reaction of fundamental and commercial importance is acetylene semi-hydrogenation. Acetylene impurity in the ethylene feedstock used in the polyethylene industry poisons the Ziegler-Natta catalyst which adversely affects the polymer quality. Pd based catalysts are most often employed for converting acetylene into the main reactant, ethylene, however, it often involves a tradeoff between the conversion and the selectivity and generally requires high temperatures. In this work, bimetallic Pd−Zn nanoparticles capped by hexadecylamine (HDA) have been synthesized by co-digestive ripening of Pd and Zn nanoparticles and studied for semi-hydrogenation of acetylene. The catalyst showed a high selectivity of ~85 % towards ethylene with a high ethylene productivity to the tune of ~4341 μmol g−1 min−1, at room temperature and atmospheric pressure. It also exhibited excellent stability with ethylene selectivity remaining greater than 85 % even after 70 h on stream. To the best of the authors’ knowledge, this is the first report of room temperature acetylene semi-hydrogenation, with the catalyst effecting high amount of acetylene conversion to ethylene retaining excellent selectivity and stability among all the reported catalysts thus far. DFT calculations show that the disordered Pd−Zn nanocatalyst prepared by a low temperature route exhibits a change in the d-band center of Pd and Zn which in turn enhances the selectivity towards ethylene. TPD, XPS and a range of catalysis experiments provided in-depth insights into the reaction mechanism, indicating the key role of particle size, surface area, Pd−Zn interactions, and the capping agent. © 2023 Wiley-VCH GmbH.

Item Type:	Journal Article
Publication:	Chemistry - A European Journal
Publisher:	John Wiley and Sons Inc
Additional Information:	The copyright for this article belongs to John Wiley and Sons Inc.
Department/Centre:	Division of Chemical Sciences > Inorganic & Physical Chemistry Division of Chemical Sciences > Materials Research Centre
Date Deposited:	20 Dec 2023 04:02
Last Modified:	20 Dec 2023 04:02
URI:	https://eprints.iisc.ac.in/id/eprint/83519

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