Governing factors of supports of ammonia synthesis in an electric field found using density functional theory

Kota Murakami, Yuta Tanaka, Sasuga Hayashi, Ryuya Sakai, Yudai Hisai, Yuta Mizutani, Atsushi Ishikawa, Takuma Higo, Shuhei Ogo, Jeong Gil Seo, Hideaki Tsuneki, Hiromi Nakai, Yasushi Sekine

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

Efficient ammonia synthesis at low temperatures is anticipated for establishing a hydrogen carrier system. We reported earlier that application of an electric field on the Cs/Ru/SrZrO3 catalyst enhanced catalytic ammonia synthesis activity. It is now clear that N2 dissociation is activated by hopping protons in the electric field. Efficient ammonia synthesis proceeds by an "associative mechanism" in which N2 dissociates via an N2H intermediate, even at low temperatures. The governing factor of ammonia synthesis activity in an electric field for active metals differed from that in the conventional mechanism. Also, N2H formation energy played an important role. The effects of dopants (Al, Y, Ba, and Ca) on this mechanism were investigated using activity tests and density functional theory calculations to gain insights into the support role in the electric field. Ba and Ca addition showed positive effects on N2H formation energy, leading to high ammonia synthesis activity. The coexistence of proton-donating and electron-donating abilities is necessary for efficient N2H formation at the Ru-support interface.

Original languageEnglish
Article number064708
JournalJournal of Chemical Physics
Volume151
Issue number6
DOIs
Publication statusPublished - 2019 Aug 14

    Fingerprint

ASJC Scopus subject areas

  • Physics and Astronomy(all)
  • Physical and Theoretical Chemistry

Cite this

Murakami, K., Tanaka, Y., Hayashi, S., Sakai, R., Hisai, Y., Mizutani, Y., Ishikawa, A., Higo, T., Ogo, S., Seo, J. G., Tsuneki, H., Nakai, H., & Sekine, Y. (2019). Governing factors of supports of ammonia synthesis in an electric field found using density functional theory. Journal of Chemical Physics, 151(6), [064708]. https://doi.org/10.1063/1.5111920