Heterogeneous Metal-Free Hydrogenation over Defect-Laden Hexagonal Boron Nitride
Heterogeneous Metal-Free Hydrogenation over Defect-Laden Hexagonal Boron Nitride
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缺陷六方氮化硼的非均相无金属氢化
DOI：
10.1021/acsomega.6b00315
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发表时间：
2016
期刊：
影响因子：
4.1
通讯作者：
Harper, James K.
中科院分区：
文献类型：
--
作者：
Nash, David J.;Restrepo, David T.;Parra, Natalia S.;Giesler, Kyle E.;Penabade, Rachel A.;Aminpour, Maral;Le, Duy;Li, Zhanyong;Farha, Omar K.;Harper, James K.
催化加氢是一个重要的过程，用于从食品到燃料的生产。目前该工艺的异质实现利用金属作为活性物质。直到最近，催化非均相加氢在无金属固体是未知的；这种系统的实施将消除与金属基催化剂有关的健康、环境和经济问题。本文报道了一种无金属多相加氢催化剂的良好加氢速率和产率，以及其独特的加氢机理。在一个设计用于最大限度地利用氮化硼薄片缺陷的反应器中，对含缺陷氮化硼（dh-BN）进行了烯烃催化加氢反应。丙烯、环己烯、1,1-二苯乙烯、(E)-和(Z)-1,2-二苯乙烯、十八烯和苄基苯乙酮的加氢反应获得了良好的收率（bbb90 %）和周转率（6 × 10-5-4 × 10-3）。乙烯在处理过的bn上的程序升温解吸表明形成了高度缺陷的结构。固体核磁共振（SSNMR）测量了高和低丙烯表面覆盖率的h- bn，显示出四种不同的结合模式。在bn中引入缺陷会产生电子缺陷和过剩区域。密度泛函理论计算表明，在硼取代氮（BN）、空位（VBand VN）和Stone-Wales缺陷这四种特定缺陷上，烯烃和氢键的顺序都降低了。SSNMR和结合能计算表明，vna最有可能是催化活性位点。这项工作表明，催化位点可以通过产生缺陷被引入到以前被认为是催化无活性的材料中。
Catalytic hydrogenation is an important process used for the production of everything from foods to fuels. Current heterogeneous implementations of this process utilize metals as the active species. Until recently, catalytic heterogeneous hydrogenation over a metal-free solid was unknown; implementation of such a system would eliminate the health, environmental, and economic concerns associated with metal-based catalysts. Here, we report good hydrogenation rates and yields for a metal-free heterogeneous hydrogenation catalyst as well as its unique hydrogenation mechanism. Catalytic hydrogenation of olefins was achieved over defect-ladenh-BN (dh-BN) in a reactor designed to maximize the defects inh-BN sheets. Good yields (>90%) and turnover frequencies (6 × 10–5–4 × 10–3) were obtained for the hydrogenation of propene, cyclohexene, 1,1-diphenylethene, (E)- and (Z)-1,2-diphenylethene, octadecene, and benzylideneacetophenone. Temperature-programmed desorption of ethene over processedh-BN indicates the formation of a highly defective structure. Solid-state NMR (SSNMR) measurements ofdh-BN with high and low propene surface coverages show four different binding modes. The introduction of defects intoh-BN creates regions of electronic deficiency and excess. Density functional theory calculations show that both the alkene and hydrogen-bond order are reduced over four specific defects: boron substitution for nitrogen (BN), vacancies (VBand VN), and Stone–Wales defects. SSNMR and binding-energy calculations show that VNare most likely the catalytically active sites. This work shows that catalytic sites can be introduced into a material previously thought to be catalytically inactive through the production of defects.
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影响因子：
12.9
作者：
Yu RP;Darmon JM;Hoyt JM;Margulieux GW;Turner ZR;Chirik PJ
通讯作者：
Chirik PJ
DOI：
--
发表时间：
1993
期刊：
影响因子：
--
作者：
S. Irandoust;J. Edvardsson
通讯作者：
J. Edvardsson
多壁氮化硼纳米管中可逆波纹的原位观察
影响因子：
3.5
作者：
H. Ghassemi;C. Lee;Y. Yap;R. Yassar
通讯作者：
R. Yassar
影响因子：
38.3
作者：
Suenaga, Kazu;Wakabayashi, Hideaki;Iijima, Sumio
通讯作者：
Iijima, Sumio
影响因子：
15
作者：
A.B.T. Soderquist;J. Facelli;W. Horton;D. Grant
通讯作者：
D. Grant