B-MWW Zeolite: The Case Against Single-Site Catalysis

被引：0

作者：

Altvater, Natalie R. ^{[1
]}

Dorn, Rick W. ^{[2
,3
]}

Cendejas, Melissa C. ^{[4
]}

McDermott, William P. ^{[4
]}

Thomas, Brijith ^{[2
]}

Rossini, Aaron J. ^{[2
,3
]}

Hermans, Ive ^{[1
,4
]}

机构：

[1] Department of Chemical and Biological Engineering, University of Madison – Wisconsin, 1415 Engineering Drive, Madison,WI,53706, United States

[2] Department of Chemistry, Iowa State University, 2438 Pammel Dr., Ames,IA,50011, United States

[3] U.S. Department of Energy, Ames Laboratory, 311 Iowa State University, Ames,IA,50011, United States

[4] Department of Chemistry, University of Wisconsin – Madison, 1101 University Avenue, Madison,WI,53706, United States

来源：

Advanced Materials | 2020年 / 132卷 / 16期

基金：

美国国家卫生研究院; 美国国家科学基金会;

关键词：

Boron - Catalyst activity - Dehydrogenation - Light polarization - Nuclear magnetic resonance spectroscopy - Propane - Zeolites;

D O I：

10.1002/ANGE.201914696

中图分类号：

学科分类号：

摘要：

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(3x/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 (BMWW). Using 11B solid-state NMR spectroscopy, we show that the majority of boron species in B-MWW exist as isolated BO3 units, 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 BO3 units are the active site in boron-based catalysts. This observation is at odds with other traditionally studied catalysts like vanadiumbased catalysts and provides an important piece of the mechanistic puzzle. © 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

引用

页码：6608 / 6612