Biomimetic catalyst development for natural gas conversion
- Sandia National Lab., Albuquerque, NM (United States)
- Univ. of California, Daivs, CA (United States)
- Florida International Univ., Miami, FL (United States)
Enzymes such as cytochrome P{sub 450} are known to catalyze difficult reactions including the partial oxidation of unactivated alkanes to alcohols. We are using computer aided molecular design (CAMD) in conjunction with activity testing to develop biomimetic catalysts for the oxidation of light alkanes. Our stepwise approach to catalyst development involves first using CAMD to design and model potential metalloporphyrin catalysts, followed by synthesis and characterization of promising catalysts, and finally utilizing our catalysts in bench scale oxidation reactions. The information gained in laboratory testing enables us to evaluate and refine our models, and thus continue to design catalysts which are incrementally better. We anticipate that this iterative approach will lead to the development of biomimetic catalysts which are active enough to use air for the conversion of natural gas to oxygentated products. Metalloporphyrins have been shown to catalyze the oxidation of light alkanes with air or oxygen as the oxidant under mild conditions with no added co-reductant. Prior work has indicated three beneficial properties of the metalloporphyrin catalysts. These activity-enhancing features are: (1) the presence of strongly electron-withdrawing substituent groups at the periphery of the porphyrin ring, (2) an axial ligand complex favoring the most negative Fe(III)/Fe(II) redox potential, and (3) steric restraints on close bimolecular face-to-face approach of catalyst molecules. We have designed and synthesized, and are currently testing a series of catalysts, the fluorinated iron dodecaphenylporphyrins (FeF{sub x}DPP where x=0,20,28,36), and with an additional feature - a rigid cavity that promotes the binding of the substrate alkane molecule.
- OSTI ID:
- 254828
- Report Number(s):
- CONF-940813--
- Country of Publication:
- United States
- Language:
- English
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