Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure
Nickel– and cobalt–cerium bimetallic oxides were used as catalysts for the methanation of CO<sub>2</sub> under pressure. The catalysts’ activity increases with pressure and an increase of just 10 bar is enough to double the yield of methane and to significantly improve the selectivity. T...
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| Format: | Article |
| Language: | English |
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MDPI AG
2021-12-01
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| Series: | Catalysts |
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| Online Access: | https://www.mdpi.com/2073-4344/12/1/44 |
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| author | Joaquim Miguel Badalo Branco Ana Cristina Ferreira Joana Filipa Martinho |
| author_facet | Joaquim Miguel Badalo Branco Ana Cristina Ferreira Joana Filipa Martinho |
| author_sort | Joaquim Miguel Badalo Branco |
| collection | DOAJ |
| description | Nickel– and cobalt–cerium bimetallic oxides were used as catalysts for the methanation of CO<sub>2</sub> under pressure. The catalysts’ activity increases with pressure and an increase of just 10 bar is enough to double the yield of methane and to significantly improve the selectivity. The best results were those obtained over nickel–cerium bimetallic oxides, but the effect of pressure was particularly relevant over cobalt–cerium bimetallic oxides, which yield to methane increases from almost zero at atmospheric pressure to 50–60% at 30 bar. Both catalyst types are remarkably competitive, especially those containing nickel, which were always more active than a commercial rhodium catalyst used as a reference (5<sub>wt</sub>.<sub>%</sub> Rh/Al<sub>2</sub>O<sub>3</sub>) and tested under the same conditions. For the cobalt–cerium bimetallic oxides, the existence of a synergetic interaction between Co and CoO and the formation of cobalt carbides seems to play an important role in their catalytic behavior. Correlation between experimental reaction rates and simulated data confirms that the catalysts’ behavior follows the <i>Langmuir–Hinshelwood–Hougen–Watson</i> kinetic model, but <i>Le Chatelier</i>’s principle is also important to understand the catalysts’ behavior under pressure. A catalyst recycle study was also performed. The results obtained after five cycles using a nickel–cerium catalyst show insignificant variations in activity and selectivity, which are important for any type of practical application. |
| first_indexed | 2024-03-10T01:45:17Z |
| format | Article |
| id | doaj.art-7c58495f0080479982a7d92d6caec8cb |
| institution | Directory Open Access Journal |
| issn | 2073-4344 |
| language | English |
| last_indexed | 2024-03-10T01:45:17Z |
| publishDate | 2021-12-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Catalysts |
| spelling | doaj.art-7c58495f0080479982a7d92d6caec8cb2023-11-23T13:16:12ZengMDPI AGCatalysts2073-43442021-12-011214410.3390/catal12010044Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of PressureJoaquim Miguel Badalo Branco0Ana Cristina Ferreira1Joana Filipa Martinho2Centro de Química Estrutural, Instituto Superior Técnico Universidade de Lisboa, Campus Tecnológico e Nuclear, Estrada Nacional 10, ao km 139.7, 2695-066 Bobadela, PortugalCentro de Química Estrutural, Instituto Superior Técnico Universidade de Lisboa, Campus Tecnológico e Nuclear, Estrada Nacional 10, ao km 139.7, 2695-066 Bobadela, PortugalCentro de Química Estrutural, Instituto Superior Técnico Universidade de Lisboa, Campus Tecnológico e Nuclear, Estrada Nacional 10, ao km 139.7, 2695-066 Bobadela, PortugalNickel– and cobalt–cerium bimetallic oxides were used as catalysts for the methanation of CO<sub>2</sub> under pressure. The catalysts’ activity increases with pressure and an increase of just 10 bar is enough to double the yield of methane and to significantly improve the selectivity. The best results were those obtained over nickel–cerium bimetallic oxides, but the effect of pressure was particularly relevant over cobalt–cerium bimetallic oxides, which yield to methane increases from almost zero at atmospheric pressure to 50–60% at 30 bar. Both catalyst types are remarkably competitive, especially those containing nickel, which were always more active than a commercial rhodium catalyst used as a reference (5<sub>wt</sub>.<sub>%</sub> Rh/Al<sub>2</sub>O<sub>3</sub>) and tested under the same conditions. For the cobalt–cerium bimetallic oxides, the existence of a synergetic interaction between Co and CoO and the formation of cobalt carbides seems to play an important role in their catalytic behavior. Correlation between experimental reaction rates and simulated data confirms that the catalysts’ behavior follows the <i>Langmuir–Hinshelwood–Hougen–Watson</i> kinetic model, but <i>Le Chatelier</i>’s principle is also important to understand the catalysts’ behavior under pressure. A catalyst recycle study was also performed. The results obtained after five cycles using a nickel–cerium catalyst show insignificant variations in activity and selectivity, which are important for any type of practical application.https://www.mdpi.com/2073-4344/12/1/44carbon dioxidemethanationcerium oxidepressurepreparation method |
| spellingShingle | Joaquim Miguel Badalo Branco Ana Cristina Ferreira Joana Filipa Martinho Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure Catalysts carbon dioxide methanation cerium oxide pressure preparation method |
| title | Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure |
| title_full | Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure |
| title_fullStr | Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure |
| title_full_unstemmed | Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure |
| title_short | Cerium <i>d</i>-Block Element (Co, Ni) Bimetallic Oxides as Catalysts for the Methanation of CO<sub>2</sub>: Effect of Pressure |
| title_sort | cerium i d i block element co ni bimetallic oxides as catalysts for the methanation of co sub 2 sub effect of pressure |
| topic | carbon dioxide methanation cerium oxide pressure preparation method |
| url | https://www.mdpi.com/2073-4344/12/1/44 |
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