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Title: Cage effects control the mechanism of methane hydroxylation in zeolites

Catalytic conversion of methane to methanol remains an economically tantalizing but fundamentally challenging goal. Current technologies based on zeolites deactivate too rapidly for practical application. We found that similar active sites hosted in different zeolite lattices can exhibit markedly different reactivity with methane, depending on the size of the zeolite pore apertures. Whereas zeolite with large pore apertures deactivates completely after a single turnover, 40% of active sites in zeolite with small pore apertures are regenerated, enabling a catalytic cycle. Detailed spectroscopic characterization of reaction intermediates and density functional theory calculations show that hindered diffusion through small pore apertures disfavors premature release of CH3radicals from the active site after C-H activation, thereby promoting radical recombination to form methanol rather than deactivated Fe-OCH3centers elsewhere in the lattice.

 
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Award ID(s):
1660611
NSF-PAR ID:
10275811
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  
Publisher / Repository:
American Association for the Advancement of Science (AAAS)
Date Published:
Journal Name:
Science
Volume:
373
Issue:
6552
ISSN:
0036-8075
Page Range / eLocation ID:
p. 327-331
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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