| Autor: |
Genoux A; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., Pauly M; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States., Rooney CL; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., Choi C; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., Shang B; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., McGuigan S; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States., Fataftah MS; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., Kayser Y; Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany., Suhr SCB; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., DeBeer S; Max Planck Institute for Chemical Energy Conversion, D-45470 Mülheim an der Ruhr, Germany., Wang H; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States., Maggard PA; Department of Chemistry, North Carolina State University, Raleigh, North Carolina 27695, United States., Holland PL; Department of Chemistry, Yale University, New Haven, Connecticut 06520, United States. |
| Abstrakt: |
Carbon nitride materials can be hosts for transition metal sites, but Mössbauer studies on iron complexes in carbon nitrides have always shown a mixture of environments and oxidation states. Here we describe the synthesis and characterization of a crystalline carbon nitride with stoichiometric iron sites that all have the same environment. The material (formula C 6 N 9 H 2 Fe 0.4 Li 1.2 Cl, abbreviated PTI/FeCl 2 ) is derived from reacting poly(triazine imide)·LiCl (PTI/LiCl) with a low-melting FeCl 2 /KCl flux, followed by anaerobic rinsing with methanol. X-ray diffraction, X-ray absorption and Mössbauer spectroscopies, and SQUID magnetometry indicate that there are tetrahedral high-spin iron(II) sites throughout the material, all having the same geometry. The material is active for electrocatalytic nitrate reduction to ammonia, with a production rate of ca . 0.1 mmol cm -2 h -1 and Faradaic efficiency of ca . 80% at -0.80 V vs RHE. |
