Abstract
Templated porous carbons are promising due to their robust chemical and thermal properties. However, investigations into the formation mechanisms and structure-property relationships are limited. We report a systematic study of the carbonization of two metal-organic frameworks (MOFs) with varying connectivities and metal centers to determine how the resulting porous carbon structure is affected by temperature and gas environment. Surface area analysis reveals that the porosity depends on the number of residual carbon species, while diffraction analysis shows the strong effect of carbonization temperature on the resulting metal oxide phase. A higher connectivity parent MOF also indicates a more controllable and typically higher-surface-area porous carbon. This effect is especially noticeable when coordinating gases are used as the calcination environment, suggesting that a kinetically controlled decoordination event is responsible for reducing the carbon surface area. Neutron total scattering and pair distribution function (PDF) analysis showed that larger carbon domain sizes also cause higher surface areas, which indicates that the formation of domains within the materials promotes rigid backbones and aids in the production of high surface areas. PDF analysis showed that the MOF template could also be used to maintain the symmetry of the parent cluster in the resulting carbon, with the Zr6O4(OH)4 of UiO-66 forming the cubic phase of the metal oxide.
| Original language | English |
|---|---|
| Pages (from-to) | 4249-4258 |
| Number of pages | 10 |
| Journal | Crystal Growth and Design |
| Volume | 21 |
| Issue number | 8 |
| DOIs | |
| State | Published - Aug 4 2021 |
Funding
This research used resources at the Spallation Neutron Source (SNS), a U.S. Department of Energy (DOE) Office of Science User Facility operated by Oak Ridge National Laboratory. G.S.D., H.F.D., and M.R.R. acknowledge the U.S. Department of Energy (DOE) Office of Science Graduate Student Research (SCGSR) program for funding. The SCGSR program is administered by the Oak Ridge Institute for Science and Education (ORISE) for the DOE under contract number DE-SC0014664. M.R.R. also acknowledges the U.S. Department of Energy (DOE) Office of Science (Basic Energy Sciences) for additional research funding and the National Energy Research Scientific Computing Center (NERSC), a DOE Office of Science User Facility operated under Contract no. DE-AC02-05CH11231, for access to supercomputing resources. A.C.-R. acknowledges the DOE Office of Science (Basic Energy Sciences) for research funding under Contract number DE-SC0017864. H.-C.Z. acknowledges the Robert A. Welch Foundation for a Welch Endowed Chair (A-0030). The authors also acknowledge the Texas A&M Microscopy and Imaging Center and Materials Characterization Facility and Dr. Tamara Powers for providing access to equipment. This manuscript has been authored by UT-Battelle, LLC, under contract DE-AC05-00OR22725 with the U.S. Department of Energy (DOE). The U.S. government retains and the publisher, by accepting the article for publication, acknowledges that the U.S. government retains a nonexclusive, paid-up, irrevocable, worldwide license to publish or reproduce the published form of this manuscript, or allow others to do so, for the U.S. government purposes. DOE will provide public access to these results of federally sponsored research in accordance with the DOE Public Access Plan ( http://energy.gov/downloads/doe-public-access-plan ). Acknowledgments
| Funders | Funder number |
|---|---|
| Office of Science Graduate Student Research | |
| SCGSR | |
| U.S. Department of Energy | |
| Welch Foundation | A-0030 |
| Office of Science | DE-AC02-05CH11231, DE-SC0017864 |
| Basic Energy Sciences | |
| Oak Ridge Institute for Science and Education | DE-SC0014664 |
| National Energy Research Scientific Computing Center |