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Lookup NU author(s): Dr Guangru Zhang, Dr Evangelos Papaioannou
This work is licensed under a Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International License (CC BY-NC-ND).
© 2022 Elsevier B.V. Carbon xerogels were synthesised and used as support of ruthenium-based catalysts for the ammonia decomposition reaction. To improve their physical-chemical properties, carbon xerogels were either activated in carbon dioxide atmosphere (for 1 and 5 h), or doped with nitrogen via co-precursor method, using urea as nitrogen source. Un-promoted and sodium-promoted ruthenium catalysts were prepared by incipient wetness impregnation. All catalysts were tested during the ammonia decomposition reaction (1 atm, 100–600 °C), showing high catalytic activity. The 5 h carbon dioxide activation treatment resulted in a decrease in oxygen surface groups (i.e. by 11 wt%) on carbon xerogels surface, and in an increase in the structure crystallinity (i.e. by 15% in the TBurn) of carbon xerogels, resulting in a higher ammonia decomposition reaction rate (i.e. 3.5-fold at 450 °C). Similarly, nitrogen addition to carbon xerogels had a positive effect on the catalysts basicity, enhancing their catalytic performance (i.e. triple reaction rate at 450 °C). The addition of sodium conferred an enhancement in the performance of each catalyst (i.e. reaction rate up to 9 times higher at 450 °C). Two ammonia decomposition reaction runs were performed for all catalysts, to test the performance reproducibility of the catalysts. It was found that un-promoted catalysts exhibited higher reaction rates (i.e. up to 3.5 times at 450 °C) during the second run of reaction due to the larger ruthenium particle size, whereas sodium-promoted catalysts exhibited similar catalytic activity in both reaction runs due to the presence of sodium oxide avoiding the sintering of ruthenium particles.
Author(s): Mazzone S, Goklany T, Zhang G, Tan J, Papaioannou EI, Garcia-Garcia FR
Publication type: Article
Publication status: Published
Journal: Applied Catalysis A: General
Year: 2022
Volume: 632
Print publication date: 25/02/2022
Online publication date: 14/01/2022
Acceptance date: 07/01/2022
Date deposited: 23/03/2022
ISSN (print): 0926-860X
ISSN (electronic): 1873-3875
Publisher: Elsevier B.V.
URL: https://doi.org/10.1016/j.apcata.2022.118484
DOI: 10.1016/j.apcata.2022.118484
ePrints DOI: 10.57711/9m41-zb38
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