XAS investigation of silica aerogel supported cobalt rhenium catalysts for ammonia decomposition.

Kirste, K. G., Laassiri, S., Hu, Z., Stoian, D., Torrente-Murciano, L., Hargreaves, J. S.J. and Mathisen, K. (2020) XAS investigation of silica aerogel supported cobalt rhenium catalysts for ammonia decomposition. Physical Chemistry Chemical Physics, 22(34), pp. 18932-18949. (doi: 10.1039/d0cp00558d) (PMID:32567607)

Abstract

The implementation of ammonia as a hydrogen vector relies on the development of active catalysts to release hydrogen on-demand at low temperatures. As an alternative to ruthenium-based catalysts, herein we report the high activity of silica aerogel supported cobalt rhenium catalysts. XANES/EXAFS studies undertaken at reaction conditions in the presence of the ammonia feed reveal that the cobalt and rhenium components of the catalyst which had been pre-reduced are initially re-oxidised prior to their subsequent reduction to metallic and bimetallic species before catalytic activity is observed. A synergistic effect is apparent in which this re-reduction step occurs at considerably lower temperatures than for the corresponding monometallic counterpart materials. The rate of hydrogen production via ammonia decomposition was determined to be 0.007 molH2 gcat−1 h−1 at 450 °C. The current study indicates that reduced Co species are crucial for the development of catalytic activity.

• Item Type: Articles
• Additional Information: LTM acknowledges financial support from the EPSRC through EP/L020423/2 and EP/N013778/1.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Laassiri, Dr Said and Hargreaves, Professor Justin
• Authors: Kirste, K. G., Laassiri, S., Hu, Z., Stoian, D., Torrente-Murciano, L., Hargreaves, J. S.J., and Mathisen, K.
• College/School: College of Science and Engineering > School of Chemistry
• Journal Name: Physical Chemistry Chemical Physics
• Publisher: Royal Society of Chemistry
• ISSN: 1463-9076
• ISSN (Online): 1463-9084
• Published Online: 12 June 2020
• Copyright Holders: Copyright © the Owner Societies 2020
• First Published: First published in Physical Chemistry Chemical Physics 22(34): 18932-18949
• Publisher Policy: Reproduced under a Creative Commons license

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
170245		First principles design of novel ammonia synthesis catalysts	Justin Hargreaves	Engineering and Physical Sciences Research Council (EPSRC)	EP/L02537X/1	Chemistry