Ultrasonically improved semi-hydrogenation of alkynes to (Z-)alkenes over novel lead-free Pd/Boehmite catalysts

Zhilin Wu; Giancarlo Cravotto; Emanuela Calcio Gaudino; Agnese Giacomino; Jonathan Medlock; Werner Bonrath

doi:10.1016/j.ultsonch.2016.05.019

Ultrasonically improved semi-hydrogenation of alkynes to (Z-)alkenes over novel lead-free Pd/Boehmite catalysts

Ultrason Sonochem. 2017 Mar;35(Pt B):664-672. doi: 10.1016/j.ultsonch.2016.05.019. Epub 2016 May 20.

Authors

Zhilin Wu¹, Giancarlo Cravotto², Emanuela Calcio Gaudino¹, Agnese Giacomino¹, Jonathan Medlock³, Werner Bonrath³

Affiliations

¹ Dipartimento di Scienza e Tecnología del Farmaco and NIS - Centre for Nanostructured Interfaces and Surfaces, Universty of Turin, Via P. Giuria 9, I-10125 Turin, Italy.
² Dipartimento di Scienza e Tecnología del Farmaco and NIS - Centre for Nanostructured Interfaces and Surfaces, Universty of Turin, Via P. Giuria 9, I-10125 Turin, Italy. Electronic address: giancarlo.cravotto@unito.it.
³ DSM Nutritional Products Ltd., Research and Development, P.O. Box 2676, 4002 Basel, Switzerland.

PMID: 27255737
DOI: 10.1016/j.ultsonch.2016.05.019

Abstract

This paper reports the application of ultrasound in the semi-hydrogenation of alkynes over two novel Pd/Boehmite catalysts. The semi-hydrogenations of phenylacetylene, diphenylacetylene and 2-butyne-1,4-diol have either been investigated in an ultrasonic bath under atmospheric hydrogen pressure, or in an ultrasonic horn reactor under 0.1-0.5MPa hydrogen pressure. Alkyne hydrogenation was suppressed by sonication under atmospheric hydrogen pressure, but promoted by sonication under 0.1MPa of hydrogen pressure. Sonication increased selectivity towards the semi-hydrogenated products in both cases. Catalyst loading, hydrogen pressure, temperature and the presence of quinoline, all impacted on hydrogenation rate, activity and selectivity to semi-hydrogenated products. Palladium leaching from the catalyst was evaluated in ethanol and hexane both under plain stirring and sonication.

Keywords: Alkynes; Catalyst activity; Catalyst selectivity; Semi-hydrogenation; Ultrasound.