Version 1
: Received: 10 August 2024 / Approved: 13 August 2024 / Online: 13 August 2024 (08:54:00 CEST)
How to cite:
Drummond, S. M.; Naglic, J.; Onsree, T.; Balijepalli, S. K.; Allegro, A.; Orraca Albino, S. N.; O’Connell, K. M.; Lauterbach, J. Promoted Ru/PrOx Catalysts for Mild Ammonia Synthesis. Preprints2024, 2024080898. https://doi.org/10.20944/preprints202408.0898.v1
Drummond, S. M.; Naglic, J.; Onsree, T.; Balijepalli, S. K.; Allegro, A.; Orraca Albino, S. N.; O’Connell, K. M.; Lauterbach, J. Promoted Ru/PrOx Catalysts for Mild Ammonia Synthesis. Preprints 2024, 2024080898. https://doi.org/10.20944/preprints202408.0898.v1
Drummond, S. M.; Naglic, J.; Onsree, T.; Balijepalli, S. K.; Allegro, A.; Orraca Albino, S. N.; O’Connell, K. M.; Lauterbach, J. Promoted Ru/PrOx Catalysts for Mild Ammonia Synthesis. Preprints2024, 2024080898. https://doi.org/10.20944/preprints202408.0898.v1
APA Style
Drummond, S. M., Naglic, J., Onsree, T., Balijepalli, S. K., Allegro, A., Orraca Albino, S. N., O’Connell, K. M., & Lauterbach, J. (2024). Promoted Ru/PrOx Catalysts for Mild Ammonia Synthesis. Preprints. https://doi.org/10.20944/preprints202408.0898.v1
Chicago/Turabian Style
Drummond, S. M., Katherine M. O’Connell and Jochen Lauterbach. 2024 "Promoted Ru/PrOx Catalysts for Mild Ammonia Synthesis" Preprints. https://doi.org/10.20944/preprints202408.0898.v1
Abstract
Ammonia synthesis is one of the most important chemical reactions. Due to thermodynamic restrictions and the reaction requirements of the current commercial iron catalysts, it is also one of the worst reactions for carbon dioxide emissions and energy usage. Ruthenium-based catalysts can substantially improve the environmental impact as they operate at lower pressures and temperatures. In this work, we provide a screening of more than 40 metals as possible promoter options based on a Ru/Pr2O3 catalyst. Cesium was the best alkali promoter and was held constant for the series of double-promoted catalysts. Ten formulations outperformed the Ru-Cs/PrOx benchmark, with barium being the best second promoter studied and the most cost-effective option. Designs of experiments were utilized to optimize both the pretreatment conditions and the promoter weight loadings of the doubly promoted catalyst. As a result, optimization led to more than a five-fold increase in activity compared to the unpromoted catalyst, therefore creating a possibility for low ruthenium ammonia synthesis catalysts to be used at scale. Further, we have explored the roles of promoters using kinetic analysis, XPS, and in situ infrared spectroscopy. Here, we have shown that the role of barium is to act as a hydrogen scavenger and donor, which may permit new active sites for the catalyst, and have demonstrated that the associative reaction mechanism is likely used for the unpromoted Ru/PrOx catalyst with hydrogenation of the triple bond of the dinitrogen occurring first before any dinitrogen bond breakage.
Chemistry and Materials Science, Chemical Engineering
Copyright:
This is an open access article distributed under the Creative Commons Attribution License which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
