Kinetic modelling of hydrogen transfer deoxygenation of a prototypical fatty acid over a bimetallic Pd60Cu40 catalyst: an investigation of the surface reaction mechanism and rate limiting step

Cheah, Kin Wai; Yusup, Suzana; Taylor, Martin J.; How, Bing Shen; Osatiashtiani, Amin; Nowakowski, Daniel J.; Bridgwater, Anthony V.; Skoulou, Vasiliki; Kyriakou, Georgios; Uemura, Yoshitmitsu

Abstract

Herein, for the first time, we demonstrate a novel continuous flow process involving the application of tetralin as a hydrogen
donor solvent for the catalytic conversion of oleic acid to diesel-like hydrocarbons, using an efficient and stable carbonsupported bimetallic PdCu catalyst. Using Pd60Cu40/C, where 60:40 is the molar ratio of each metal, at optimum reaction
conditions (360 °C and WHSV = 1 h-1), 90.5% oleic acid conversion and 80.5% selectivity to C17 and C18 paraffinic hydrocarbons
were achieved. Furthermore, a comprehensive mechanistic based kinetic modelling - considering power rate law, L-H and
E-R models was conducted. Kinetic expressions derived from the three kinetic models were investigated in rate data fitting
through nonlinear regression using a Levenberg-Marquardt algorithm. Based on the statistical discrimination criteria, the
experimental data of the dehydrogenation reaction of tetralin was best fitted by an L-H rate equation assuming the surface
reaction as the rate controlling step. On the contrary, the kinetic data of the oleic acid deoxygenation reaction was well
correlated with an L-H rate equation assuming single site adsorption of oleic acid with dissociative H2 adsorption. It was
found that the rate limiting step of the overall reaction was the hydrogenation of oleic acid with an activation energy of 75.0
± 5.1 kJ mol-1 whereas the dehydrogenation of tetralin had a lower activation energy of 66.4 ± 2.7 kJ mol-1.

Citation

Cheah, K. W., Yusup, S., Taylor, M. J., How, B. S., Osatiashtiani, A., Nowakowski, D. J., Bridgwater, A. V., Skoulou, V., Kyriakou, G., & Uemura, Y. (2020). Kinetic modelling of hydrogen transfer deoxygenation of a prototypical fatty acid over a bimetallic Pd60Cu40 catalyst: an investigation of the surface reaction mechanism and rate limiting step. Reaction Chemistry and Engineering, 5(9), 1682-1693. https://doi.org/10.1039/d0re00214c

• Journal Article Type: Article
• Acceptance Date: Jul 21, 2020
• Online Publication Date: Jul 21, 2020
• Publication Date: 2020-09
• Deposit Date: Jul 21, 2020
• Publicly Available Date: Jul 22, 2021
• Journal: Reaction Chemistry and Engineering
• Print ISSN: 2058-9883
• Publisher: Royal Society of Chemistry
• Peer Reviewed: Peer Reviewed
• Volume: 5
• Issue: 9
• Pages: 1682-1693
• DOI: https://doi.org/10.1039/d0re00214c
• Public URL: https://hull-repository.worktribe.com/output/3081840
• Additional Information: : This document is Similarity Check deposited; : Supplementary Information; : Kin Wai Cheah (ORCID); : Suzana Yusup (ORCID); : Martin J. Taylor (ORCID); : Amin Osatiashtiani (ORCID); : Amin Osatiashtiani (ResearcherID); : Daniel J. Nowakowski (ResearcherID); : Georgios Kyriakou (ORCID); : Single-blind; : Received 27 May 2020; Accepted 21 July 2020; Accepted Manuscript published 21 July 2020; Advance Article published 28 July 2020