On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis

Tarka, Aleksandra; Zybert, Magdalena; Ronduda, Hubert; Patkowski, Wojciech; Mierzwa, Bogusław; Kępiński, Leszek; Raróg-Pilecka, Wioletta

doi:10.3390/catal12020199

Open AccessArticle

On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis

by

Aleksandra Tarka

¹,

Magdalena Zybert

¹

,

Hubert Ronduda

¹

,

Wojciech Patkowski

¹

,

Bogusław Mierzwa

²,

Leszek Kępiński

³ and

Wioletta Raróg-Pilecka

^1,*

¹

Faculty of Chemistry, Warsaw University of Technology, Noakowskiego 3, 00-664 Warsaw, Poland

²

Institute of Physical Chemistry, Polish Academy of Sciences, Kasprzaka 44/52, 01-224 Warsaw, Poland

³

Institute of Low Temperature and Structure Research, Polish Academy of Sciences, Okólna 2, 50-950 Wrocław, Poland

^*

Author to whom correspondence should be addressed.

Catalysts 2022, 12(2), 199; https://doi.org/10.3390/catal12020199

Submission received: 30 December 2021 / Revised: 31 January 2022 / Accepted: 3 February 2022 / Published: 6 February 2022

(This article belongs to the Special Issue Applied Catalysis in Chemical Industry: Synthesis, Catalyst Design, and Evaluation)

Download

Browse Figures

Versions Notes

Abstract

High priority in developing an efficient cobalt catalyst for ammonia synthesis involves optimizing its composition in terms of the content of promoters. In this work, a series of cobalt catalysts doubly promoted with cerium and barium was prepared and tested in ammonia synthesis (H₂/N₂ = 3, 6.3 MPa, 400 °C). Barium content was studied in the range of 0–2.6 mmol g_Co⁻¹. Detailed characterization studies by nitrogen physisorption, SEM-EDX, XRPD, H₂-TPR, and H₂-TPD showed the impact of barium loading in CoCeBa catalysts on the physicochemical properties and activity of the catalysts. The most pronounced effect was observed in the development of the active phase surface, a differentiation of weakly and strongly binding sites on the catalyst surface and changes in cobalt surface activity (TOF). Barium content in the range of 1.1–1.6 mmol g_Co⁻¹ leads to obtaining a catalyst with the most favorable properties. Its excellent catalytic performance is ascribed to the appropriate Ba/Ce molar ratio, i.e., greater than unity, which results in not only a structural promotion of barium, but also a modifying action associated with the in-situ formation of the BaCeO₃ phase.

Keywords: ammonia synthesis; cobalt catalyst; barium; promoter; optimization

Graphical Abstract

Share and Cite

MDPI and ACS Style

Tarka, A.; Zybert, M.; Ronduda, H.; Patkowski, W.; Mierzwa, B.; Kępiński, L.; Raróg-Pilecka, W. On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis. Catalysts 2022, 12, 199. https://doi.org/10.3390/catal12020199

AMA Style

Tarka A, Zybert M, Ronduda H, Patkowski W, Mierzwa B, Kępiński L, Raróg-Pilecka W. On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis. Catalysts. 2022; 12(2):199. https://doi.org/10.3390/catal12020199

Chicago/Turabian Style

Tarka, Aleksandra, Magdalena Zybert, Hubert Ronduda, Wojciech Patkowski, Bogusław Mierzwa, Leszek Kępiński, and Wioletta Raróg-Pilecka. 2022. "On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis" Catalysts 12, no. 2: 199. https://doi.org/10.3390/catal12020199

APA Style

Tarka, A., Zybert, M., Ronduda, H., Patkowski, W., Mierzwa, B., Kępiński, L., & Raróg-Pilecka, W. (2022). On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis. Catalysts, 12(2), 199. https://doi.org/10.3390/catal12020199

Note that from the first issue of 2016, this journal uses article numbers instead of page numbers. See further details here.

Article Menu

On Optimal Barium Promoter Content in a Cobalt Catalyst for Ammonia Synthesis

Abstract

Share and Cite

Article Metrics

Article Access Statistics

Further Information

Guidelines

MDPI Initiatives

Follow MDPI