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).

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.

On the nature of framework Brønsted and Lewis acid sites in ZSM-5

Zeolites ◽  
1997 ◽  
Vol 19 (4) ◽  
pp. 288-296 ◽  
Author(s):  
G.L. Woolery ◽  
G.H. Kuehl ◽  
H.C. Timken ◽  
A.W. Chester ◽  
J.C. Vartuli
Keyword(s):  
Lewis Acid ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Brønsted And Lewis Acid

Enhancing Brønsted and Lewis Acid Sites of the Utilized Spent RFCC Catalyst Waste for the Continuous Cracking Process of Palm Oil to Biofuels

2020 ◽  
Vol 59 (20) ◽  
pp. 9459-9468 ◽  
Author(s):  
I. Istadi ◽  
Teguh Riyanto ◽  
Luqman Buchori ◽  
Didi Dwi Anggoro ◽  
G. Gilbert ◽  
...  
Keyword(s):  
Lewis Acid ◽  
Palm Oil ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Cracking Process ◽  
Brønsted And Lewis Acid

High activity of aluminated bifunctional mesoporous silica nanoparticles for cumene hydrocracking and measurement of molar absorption coefficient

2015 ◽  
Vol 39 (10) ◽  
pp. 8006-8016 ◽  
Author(s):  
Mohammad Reza Sazegar ◽  
Sugeng Triwahyono ◽  
Aishah Abdul Jalil ◽  
Rino R. Mukti ◽  
Seyed Mohammad Seyed Mohaghegh ◽  
...  
Keyword(s):  
Mesoporous Silica ◽  
Absorption Coefficient ◽  
Silica Nanoparticles ◽  
High Activity ◽  
Lewis Acid ◽  
Mesoporous Silica Nanoparticles ◽  
Acid Sites ◽  
Molar Absorption Coefficient ◽  
Lewis Acid Sites ◽  
Brønsted And Lewis Acid

Pt/HAlMSN synthesized with Si/Al ratios = 7–50 showed high activity in cumene hydrocracking due to the Brønsted and Lewis acid sites.

Time-resolved observation of V2O5/TiO2 in NH3-SCR reveals the equivalence of Brønsted and Lewis acid sites

2020 ◽  
Vol 56 (98) ◽  
pp. 15450-15453
Author(s):  
Inhak Song ◽  
Hwangho Lee ◽  
Se Won Jeon ◽  
Taejin Kim ◽  
Do Heui Kim
Keyword(s):  
Lewis Acid ◽  
Catalytic Reaction ◽  
Reaction Rates ◽  
Acid Sites ◽  
Lewis Acid Sites ◽  
Time Resolved ◽  
Nh3 Scr ◽  
Brønsted And Lewis Acid

Reaction rates of Lewis-NH3 and Brønsted-NH3 species were measured to be equivalent in the selective catalytic reaction over V2O5/TiO2 catalyst.

scholarly journals Solid Acids for the Reaction of Bioderived Alcohols into Ethers for Fuel Applications

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 172 ◽  
Author(s):  
Federica Zaccheria ◽  
Nicola Scotti ◽  
Nicoletta Ravasio
Keyword(s):  
Physical Properties ◽  
Lignocellulosic Biomass ◽  
Lewis Acid ◽  
Product Distribution ◽  
Acid Sites ◽  
Solid Acids ◽  
Lewis Acid Sites ◽  
Hydroxymethyl Furfural ◽  
Brønsted And Lewis Acid

The use of solids acids in the synthesis of ethers suitable to be used as fuels or fuel additives were reviewed in a critical way. In particular, the role of Brønsted and Lewis acid sites was highlighted to focus on the pivotal role of the acidity nature on the product distribution. Particular emphasis is given to the recently proposed ethers prepared starting from furfural and 5-hydroxymethyl furfural. Thus, they are very promising products that can be derived from lignocellulosic biomass and bioalcohols and possess very interesting chemical and physical properties for their use in the diesel sector.

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