TY - JOUR
T1 - Realization of Ideal Ba Promoter State by Simultaneous Incorporation with Co into Carbon-protective Framework for Ammonia Synthesis Catalyst
AU - De Silva, K. Kanishka H.
AU - Sato, Katsutoshi
AU - Naito, Takahiro
AU - Toriyama, Takaaki
AU - Yamamoto, Tomokazu
AU - Aso, Ryotaro
AU - Murakami, Yasukazu
AU - Varadwaj, Pradeep R.
AU - Asahi, Ryoji
AU - Inazu, Koji
AU - Nagaoka, Katsutoshi
N1 - Publisher Copyright:
© 2024 The Author(s). Advanced Energy Materials published by Wiley-VCH GmbH.
PY - 2024
Y1 - 2024
N2 - Developing non-noble metal catalysts with excellent NH3 synthesis activity under mild conditions is a long-term goal. The best catalysts reported to date often require laborious fabrication methods and controlled environments to fabricate the catalysts or high temperatures and long times to activate the catalysts. This work introduces a facile one-pot method to fabricate carbon (C)-based, barium (Ba)-promoted cobalt (Co) catalysts via the citric acid sol–gel method with metal nitrates as precursors and water as the solvent. This approach ensures the homogeneous incorporation of metal ions into the carbon framework. The resulting (Ba/Co)0.3/C catalyst demonstrates an outstanding NH3 synthesis activity of 34 mmol gcat−1 h−1 (350 °C, 1.0 MPa) with excellent stability. In-depth characterizations reveal that Ba exists as barium oxide (BaO), uniformly distributed on the carbon framework and around the Co nanoparticles. It is uncovered that retarding barium carbonate (BaCO3) formation in the fresh catalyst significantly reduces the reduction temperature and time (485 °C/4 h), which is a fundamental advantage of this method. Density functional theory and molecular dynamics simulations indeed support the experimental observations. It is anticipated that this simple and economical strategy will resolve the issues in a broad field of heterogeneous catalyst research.
AB - Developing non-noble metal catalysts with excellent NH3 synthesis activity under mild conditions is a long-term goal. The best catalysts reported to date often require laborious fabrication methods and controlled environments to fabricate the catalysts or high temperatures and long times to activate the catalysts. This work introduces a facile one-pot method to fabricate carbon (C)-based, barium (Ba)-promoted cobalt (Co) catalysts via the citric acid sol–gel method with metal nitrates as precursors and water as the solvent. This approach ensures the homogeneous incorporation of metal ions into the carbon framework. The resulting (Ba/Co)0.3/C catalyst demonstrates an outstanding NH3 synthesis activity of 34 mmol gcat−1 h−1 (350 °C, 1.0 MPa) with excellent stability. In-depth characterizations reveal that Ba exists as barium oxide (BaO), uniformly distributed on the carbon framework and around the Co nanoparticles. It is uncovered that retarding barium carbonate (BaCO3) formation in the fresh catalyst significantly reduces the reduction temperature and time (485 °C/4 h), which is a fundamental advantage of this method. Density functional theory and molecular dynamics simulations indeed support the experimental observations. It is anticipated that this simple and economical strategy will resolve the issues in a broad field of heterogeneous catalyst research.
KW - basic promoters
KW - citric acid sol–gel method
KW - green ammonia synthesis
KW - metal-carbon framework
KW - mild activation conditions
KW - renewable energy
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U2 - 10.1002/aenm.202404030
DO - 10.1002/aenm.202404030
M3 - Article
AN - SCOPUS:85211469215
SN - 1614-6832
JO - Advanced Energy Materials
JF - Advanced Energy Materials
ER -