Abstract
We report a strategy to integrate atomically dispersed iron within a heterogeneous nitrogen-doped carbon (N-C) support, inspired by routes for metalation of molecular macrocyclic iron complexes. The N-C support, derived from pyrolysis of a ZIF-8 metal-organic framework, is metalated via solution-phase reaction with FeCl2 and tributyl amine, as a Brønsted base, at 150 °C. Fe active sites are characterized by 57Fe Mössbauer spectroscopy and aberration-corrected scanning transmission electron microscopy. The site density can be increased by selective removal of Zn2+ ions from the N-C support prior to metalation, resembling the transmetalation strategy commonly employed for the preparation of molecular Fe-macrocycles. The utility of this approach is validated by the higher catalytic rates (per total Fe) of these materials relative to established Fe-N-C catalysts, benchmarked using an aerobic oxidation reaction.
| Original language | English |
|---|---|
| Pages (from-to) | 18797-18802 |
| Number of pages | 6 |
| Journal | Journal of the American Chemical Society |
| Volume | 144 |
| Issue number | 41 |
| DOIs | |
| State | Published - Oct 19 2022 |
Funding
The authors thank Cathy Clewett for assistance with Mössbauer spectroscopy. This research was supported by the U.S. Department of Energy, Office of Science, Basic Energy Sciences, under award no. DE-FG02-05ER15690, and by a Ruth L. Kirschstein NRSA fellowship from the NIH (F32GM137472, to J.S.B.). Electron microscopy research was supported by the Center for Nanophase Materials Sciences (CNMS), which is a U.S. Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory. Spectroscopic instrumentation was partially supported by the NIH (1S10 OD020022-1) and the NSF (CHE-1048642). The Mössbauer MS4 spectrometer was supported by the Department of Chemistry, University of Wisconsin–Madison. ICP-OES instrumentation at the Water Sciences Engineering Laboratory was supported by the University of Wisconsin.
| Funders | Funder number |
|---|---|
| Center for Nanophase Materials Sciences | |
| Department of Chemistry, University of Wisconsin–Madison | |
| National Science Foundation | CHE-1048642 |
| National Institutes of Health | F32GM137472 |
| U.S. Department of Energy | |
| NIH Office of the Director | S10OD020022 |
| Office of Science | |
| Basic Energy Sciences | DE-FG02-05ER15690 |
| Oak Ridge National Laboratory | 1S10 OD020022-1 |
| University of Wisconsin-Madison | |
| Israel National Road Safety Authority |