Solid solution for catalytic ammonia synthesis from nitrogen and hydrogen gases at 50 °C.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 32332727.
- Also identified by DOI 10.1038/s41467-020-15868-8 and PMC identifier 7181780.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The lack of efficient catalysts for ammonia synthesis from N<sub>2</sub> and H<sub>2</sub> gases at the lower temperature of ca. 50 °C has been a problem not only for the Haber-Bosch process, but also for ammonia production toward zero CO<sub>2</sub> emissions. Here, we report a new approach for low temperature ammonia synthesis that uses a stable electron-donating heterogeneous catalyst, cubic CaFH, a solid solution of CaF<sub>2</sub> and CaH<sub>2</sub> formed at low temperatures. The catalyst produced ammonia from N<sub>2</sub> and H<sub>2</sub> gases at 50 °C with an extremely small activation energy of 20 kJ mol<sup>-1</sup>, which is less than half that for conventional catalysts reported. The catalytic performance can be attributed to the weak ionic bonds between Ca<sup>2+</sup> and H<sup>-</sup> ions in the solid solution and the facile release of hydrogen atoms from H<sup>-</sup> sites.