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Title: B‐MWW Zeolite: The Case Against Single‐Site Catalysis
Abstract

Boron‐containing materials have recently been identified as highly selective catalysts for the oxidative dehydrogenation (ODH) of alkanes to olefins. It has previously been demonstrated by several spectroscopic characterization techniques that the surface of these boron‐containing ODH catalysts oxidize and hydrolyze under reaction conditions, forming an amorphous B2(OH)xO(3−x/2)(x=0–6) layer. Yet, the precise nature of the active site(s) remains elusive. In this Communication, we provide a detailed characterization of zeolite MCM‐22 isomorphously substituted with boron (B‐MWW). Using11B solid‐state NMR spectroscopy, we show that the majority of boron species in B‐MWW exist as isolated BO3units, fully incorporated into the zeolite framework. However, this material shows no catalytic activity for ODH of propane to propene. The catalytic inactivity of B‐MWW for ODH of propane falsifies the hypothesis that site‐isolated BO3units are the active site in boron‐based catalysts. This observation is at odds with other traditionally studied catalysts like vanadium‐based catalysts and provides an important piece of the mechanistic puzzle.

 
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Award ID(s):
1916809 1916775
NSF-PAR ID:
10136805
Author(s) / Creator(s):
 ;  ;  ;  ;  ;  ;  
Publisher / Repository:
Wiley Blackwell (John Wiley & Sons)
Date Published:
Journal Name:
Angewandte Chemie International Edition
Volume:
59
Issue:
16
ISSN:
1433-7851
Page Range / eLocation ID:
p. 6546-6550
Format(s):
Medium: X
Sponsoring Org:
National Science Foundation
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