scholarly journals Characterization of Lewis acid sites on the (100) surface of β-AlF3: Ab initio calculations of NH3 adsorption

2008 ◽  
Vol 128 (22) ◽  
pp. 224703 ◽  
Author(s):  
C. L. Bailey ◽  
A. Wander ◽  
S. Mukhopadhyay ◽  
B. G. Searle ◽  
N. M. Harrison
Keyword(s):  
Ab Initio Calculations ◽  
Ab Initio ◽  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Nh3 Adsorption

Identification of possible Lewis acid sites on the β-AlF3(100) surface: an ab initio total energy study

2005 ◽  
Vol 7 (23) ◽  
pp. 3989 ◽  
Author(s):  
Adrian Wander ◽  
Christine L. Bailey ◽  
Barry G. Searle ◽  
Sanghamitra Mukhopadhyay ◽  
Nicholas M. Harrison
Keyword(s):  
Total Energy ◽  
Ab Initio ◽  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites

Unraveling the ultrafast behavior of nile red interacting with aluminum and titanium co-doped MCM41 materials

2016 ◽  
Vol 18 (3) ◽  
pp. 2152-2163 ◽  
Author(s):  
Cristina Martin ◽  
Boiko Cohen ◽  
María Teresa Navarro ◽  
Avelino Corma ◽  
Abderrazzak Douhal
Keyword(s):  
Lewis Acid ◽  
Nile Red ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Brønsted And Lewis Acid ◽  
Co Doped

Spectroscopic and photodynamic characterization of Nile Red during interaction with Brønsted and Lewis acid sites within single- and multi-metal(X)-doped MCM41 materials (X = Ti and/or Al).

Characterization of Lewis-acid sites in zeolites by EPR using the NO molecule as a probe

1996 ◽  
Vol 92 (13) ◽  
pp. 2495 ◽  
Author(s):  
Aleksander Gutsze ◽  
Martin Plato ◽  
Hellmut G. Karge ◽  
Frank Witzel
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites

Incorporation of Aluminum and Iron Into the ZSM-12 Zeolite: Synthesis and Characterization of Acid Sites

2002 ◽  
Vol 67 (12) ◽  
pp. 1760-1778 ◽  
Author(s):  
Gabriela Košová ◽  
Jiří Čejka
Keyword(s):  
Lewis Acid ◽  
Crystallization Rate ◽  
Acid Sites ◽  
Sodium Ion ◽  
Synthesis And Characterization ◽  
Lewis Acid Sites ◽  
Structure Directing Agent ◽  
Trivalent Cations ◽  
Brønsted And Lewis Acid

Zeolite ZSM-12 with aluminum and iron in the framework was synthesized in a broad range of Si/Al (Si/Fe) ratios using triethylmethylammonium bromide as structure-directing agent with the aim to characterize the type and concentration of acid sites in dependence on the Si/Al (Si/Fe) ratio and calcination procedure. It was shown that the minimum Si/Al ratio achieved for (Al)ZSM-12 is around 35, which is very close to the minimum Si/Fe ratio ca 37 for (Fe)ZSM-12. The rate of crystallization of (Al)ZSM-12 and (Fe)ZSM-12 depends on the concentration of Al and Fe in the reaction mixture. The higher was the concentration of these trivalent cations, the slower was the apparent crystallization rate. It is suggested that the crystallization rate is controlled by the number of nucleation centers, which depends on the amount of trivalent cations (Al, Fe) in the reaction mixture. Zeolites (Al)ZSM-12 and (Fe)ZSM-12 were calcined under a variety of carefully controlled conditions to investigate the resulting concentration of Brønsted and Lewis acid sites. FTIR spectroscopy used to study the adsorption of acetonitrile-d3 and pyridine on Brønsted and Lewis acid sites revealed that both sites are present in significant concentrations in all calcined (Al)ZSM-12 and (Fe)ZSM-12 zeolites. The highest concentrations of Brønsted sites especially at low Si/Al or Si/Fe ratios were achieved via calcination of the zeolites in a stream of ammonia followed by a repeated sodium ion exchange and further calcination in a stream of air.

scholarly journals Electronic structure of Lewis acid sites on high surface area aluminium fluorides: a combined XPS and ab initio investigation

2009 ◽  
Vol 11 (27) ◽  
pp. 5664 ◽  
Author(s):  
Anna Makarowicz ◽  
Christine L. Bailey ◽  
Norbert Weiher ◽  
Erhard Kemnitz ◽  
Sven L. M. Schroeder ◽  
...  
Keyword(s):  
Electronic Structure ◽  
Ab Initio ◽  
Surface Area ◽  
Lewis Acid ◽  
High Surface ◽  
High Surface Area ◽  
Acid Sites ◽  
Lewis Acid Sites

Periodic density functional investigation of Lewis acid sites in zeolites: relative strength order as revealed from NH3 adsorption

2005 ◽  
Vol 246 (1-3) ◽  
pp. 96-101 ◽  
Author(s):  
Mohamed Elanany ◽  
Michihisa Koyama ◽  
Momoji Kubo ◽  
Ewa Broclawik ◽  
Akira Miyamoto
Keyword(s):  
Lewis Acid ◽  
Density Functional ◽  
Acid Sites ◽  
Relative Strength ◽  
Lewis Acid Sites ◽  
Nh3 Adsorption ◽  
Functional Investigation

Generation and Characterization of Well-Defined Zn2+Lewis Acid Sites in Ion Exchanged Zeolite BEA

2004 ◽  
Vol 108 (13) ◽  
pp. 4116-4126 ◽  
Author(s):  
Jochen Penzien ◽  
Anuji Abraham ◽  
Jeroen A. van Bokhoven ◽  
Andreas Jentys ◽  
Thomas E. Müller ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites
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