Mechanistic insight into the application of alumina-supported Pd catalysts for the hydrogenation of nitrobenzene to aniline

Morisse, C. G.A., Mccullagh, A. M., Campbell, J. W., Mitchell, C., Carr, R. H. and Lennon, D. (2022) Mechanistic insight into the application of alumina-supported Pd catalysts for the hydrogenation of nitrobenzene to aniline. Industrial and Engineering Chemistry Research, 61(30), pp. 10712-10722. (doi: 10.1021/acs.iecr.2c01134) (PMCID:PMC9354085)

Abstract

Two Pd/γ-Al2O3 catalysts are examined for the vapor phase hydrogenation of nitrobenzene over the temperature range of 60–200 °C. A 1 wt % catalyst is selected as a reference material that is diluted with γ-alumina to produce a 0.3 wt % sample, which is representative of a metal loading linked to a candidate industrial specification aniline synthesis catalyst. Cyclohexanone oxime is identified as a by-product that is associated with reagent transformation. Temperature-programed infrared spectroscopy and temperature-programed desorption measurements of chemisorbed CO provide information on the morphology of the crystallites of the higher Pd loading catalyst. The lower Pd loading sample exhibits a higher aniline selectivity by virtue of minimization of product overhydrogenation. Reaction testing measurements that were undertaken employing elevated hydrogen flow rates lead to the proposition of separate reagent and product-derived by-product formation pathways, each of which occurs in a consecutive manner. A global reaction scheme is proposed that defines the by-product distribution accessible by the grades of catalyst examined. This information is helpful in defining product purification procedures that would be required in certain heat recovery scenarios connected with large-scale aniline production.

• Item Type: Articles
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Campbell, Mr James and Mccullagh, Miss Annelouise and Lennon, Professor David and Morisse, Mr Clement
• Authors: Morisse, C. G.A., Mccullagh, A. M., Campbell, J. W., Mitchell, C., Carr, R. H., and Lennon, D.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Industrial and Engineering Chemistry Research
• Publisher: American Chemical Society
• ISSN: 0888-5885
• ISSN (Online): 1520-5045
• Published Online: 14 July 2022
• Copyright Holders: Copyright © 2022 The Authors
• First Published: First published in Industrial and Engineering Chemistry Research 61(30): 10712-10722
• Publisher Policy: Reproduced under a Creative Commons License

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
172865		EPSRC DTP 16/17 and 17/18	Mary Beth Kneafsey	Engineering and Physical Sciences Research Council (EPSRC)	EP/N509668/1	Research and Innovation Services
305200		DTP 2018-19 University of Glasgow	Mary Beth Kneafsey	Engineering and Physical Sciences Research Council (EPSRC)	EP/R513222/1	MVLS - Graduate School