Issue 34, 2020

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

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.

Graphical abstract: XAS investigation of silica aerogel supported cobalt rhenium catalysts for ammonia decomposition

Supplementary files

Article information

Article type
Paper
Submitted
03 feb 2020
Accepted
11 jun 2020
First published
12 jun 2020
This article is Open Access
Creative Commons BY license

Phys. Chem. Chem. Phys., 2020,22, 18932-18949

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

K. G. Kirste, S. Laassiri, Z. Hu, D. Stoian, L. Torrente-Murciano, J. S. J. Hargreaves and K. Mathisen, Phys. Chem. Chem. Phys., 2020, 22, 18932 DOI: 10.1039/D0CP00558D

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