Cobalt Metallopeptide Electrocatalyst for the Selective Reduction of Nitrite to Ammonium

Guo Y., Stroka J. R., Kandemir B., Dickerson C. E., Bren K. L.

JOURNAL OF THE AMERICAN CHEMICAL SOCIETY, cilt.140, sa.49, ss.16888-16892, 2018 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 140 Sayı: 49
  • Basım Tarihi: 2018
  • Doi Numarası: 10.1021/jacs.8b09612
  • Dergi Adı: JOURNAL OF THE AMERICAN CHEMICAL SOCIETY
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus
  • Sayfa Sayıları: ss.16888-16892
  • Orta Doğu Teknik Üniversitesi Adresli: Hayır

Özet

A cobalt-tripeptide complex (CoGGH) is developed as an electrocatalyst for the selective six-electron, eight-proton reduction of nitrite to ammonium in aqueous buffer near neutral pH. The onset potential for nitrite reduction occurs at -0.65 V vs Ag/AgCl (1 M KCl). Controlled potential electrolysis at -0.90 V generates ammonium with a faradaic efficiency of 90 +/- 3% and a turnover number of 3550 +/- 420 over 5.5 h. CoGGH also catalyzes the reduction of the proposed intermediates nitric oxide and hydroxylamine to ammonium. These results reveal that a simple metallopeptide is an active functional mimic of the complex enzymes cytochrome c nitrite reductase and siroheme-containing nitrite reductase.