scholarly journals Spatial differentiation of Brønsted acid sites by probe molecule in zeolite USY using synchrotron X-ray powder diffraction

2017 ◽  
Vol 53 (70) ◽  
pp. 9725-9728 ◽  
Author(s):  
Lin Ye ◽  
Ivo Teixeira ◽  
Benedict T. W. Lo ◽  
Pu Zhao ◽  
S. C. Edman Tsang
Keyword(s):  
Rietveld Refinement ◽  
Powder Diffraction ◽  
Acid Site ◽  
Spatial Differentiation ◽  
Acid Sites ◽  
Probe Molecule ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
X Ray ◽  
Brönsted Acid

A direct correlation of extra-framework Al3+ in a sodalite cage (HY) with the enhanced Brønsted acid site evaluated by synchrotron X-ray powder diffraction, Rietveld refinement and the use of a pyridine probe molecule.

The Determination of Brønsted Acid Sites in Zeolite ERS-7 by Neutron and X-ray Powder Diffraction

2001 ◽  
Vol 105 (10) ◽  
pp. 1947-1955 ◽  
Author(s):  
B. J. Campbell ◽  
A. K. Cheetham ◽  
T. Vogt ◽  
L. Carluccio ◽  
W. O. Parker ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brønsted Acid Sites ◽  
X Ray ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Bronsted Acid Sites

scholarly journals Elucidation of Adsorbate Structures and Interactions on Brønsted Acid Sites in H-ZSM-5 by Synchrotron X-ray Powder Diffraction

2016 ◽  
Vol 128 (20) ◽  
pp. 6085-6088 ◽  
Author(s):  
Benedict T. W. Lo ◽  
Lin Ye ◽  
Jin Qu ◽  
Junliang Sun ◽  
Junlin Zheng ◽  
...  
Keyword(s):  
Powder Diffraction ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brønsted Acid Sites ◽  
X Ray ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Bronsted Acid Sites

Simple quantification of zeolite acid site density by reactive gas chromatography

2017 ◽  
Vol 7 (17) ◽  
pp. 3831-3841 ◽  
Author(s):  
Omar A. Abdelrahman ◽  
Katherine P. Vinter ◽  
Limin Ren ◽  
Dandan Xu ◽  
Raymond J. Gorte ◽  
...  
Keyword(s):  
Gas Chromatography ◽  
Acid Site ◽  
Single Unit ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Site Density ◽  
Brönsted Acid ◽  
A New Technique ◽  
Reactive Gas

The Brønsted acid site densities of ZSM-5, BEA and single unit cell self-pillared pentasil (SPP) zeolites of varying Si/Al ratios were measured using a new technique, reactive gas chromatography (RGC), which utilizes alkylamine decomposition to selectively count Brønsted acid sites.

Acid Strength Measurement of Zeolites by the TPD-IR Technique with Ammonia as Probe Molecule

2013 ◽  
Vol 475-476 ◽  
pp. 1270-1274
Author(s):  
Bin Wang ◽  
Ying Zhang ◽  
Fu Bo Gu ◽  
Min Zuo ◽  
Guang Sheng Guo
Keyword(s):  
Acid Sites ◽  
Acid Strength ◽  
Probe Molecule ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brønsted Acid Sites ◽  
Hy Zeolite ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Bronsted Acid Sites

An improved TPD-IR technique was developed recently. By which means, acid properties of Brønsted acid sites on HY zeolite and SAPO-34 zeolite were studied by an advanced TPD-IR technique with ammonia as probe molecule. Desorption activation energy (DAE) of the probe molecule adsorbed on zeolite was used as a measure of the acid strength. The result indicates the Brønsted acid sites of HY Zeolite or SAPO-34 zeolite were divided into two types with the strength of DAE of ammonia 43.4KJ/mol, 24.4KJ/mol and 33.2KJ/mol, 20.5KJ/mol. It is concluded that HY zeolite has the stronger Brønsted acid sites than that of SAPO-34 zeolite.

scholarly journals On the Role of Protonic Acid Sites in Cu Loaded FAU31 Zeolite as a Catalyst for the Catalytic Transformation of Furfural to Furan

Molecules ◽  
2021 ◽  
Vol 26 (7) ◽  
pp. 2015
Author(s):  
Łukasz Kuterasiński ◽  
Małgorzata Smoliło-Utrata ◽  
Joanna Kaim ◽  
Wojciech Rojek ◽  
Jerzy Podobiński ◽  
...  
Keyword(s):  
Active Sites ◽  
Acid Sites ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Brønsted Acid Sites ◽  
Protonic Acid ◽  
Brönsted Acid ◽  
Brönsted Acid Sites ◽  
Bronsted Acid Sites

The aim of the present paper is to study the speciation and the role of different active site types (copper species and Brønsted acid sites) in the direct synthesis of furan from furfural catalyzed by copper-exchanged FAU31 zeolite. Four series of samples were prepared by using different conditions of post-synthesis treatment, which exhibit none, one or two types of active sites. The catalysts were characterized by XRD, low-temperature sorption of nitrogen, SEM, H2-TPR, NMR and by means of IR spectroscopy with ammonia and CO sorption as probe molecules to assess the types of active sites. All catalyst underwent catalytic tests. The performed experiments allowed to propose the relation between the kind of active centers (Cu or Brønsted acid sites) and the type of detected products (2-metylfuran and furan) obtained in the studied reaction. It was found that the production of 2-methylfuran (in trace amounts) is determined by the presence of the redox-type centers, while the protonic acid sites are mainly responsible for the furan production and catalytic activity in the whole temperature range. All studied catalysts revealed very high susceptibility to coking due to polymerization of furfural.

Effects of Brønsted acid site proximity in chabazite zeolites on OH infrared spectra and protolytic propane cracking kinetics

2021 ◽  
Vol 395 ◽  
pp. 210-226
Author(s):  
Philip M. Kester ◽  
Jerry T. Crum ◽  
Sichi Li ◽  
William F. Schneider ◽  
Rajamani Gounder
Keyword(s):  
Infrared Spectra ◽  
Acid Site ◽  
Bronsted Acid ◽  
Brønsted Acid ◽  
Bronsted Acid Site ◽  
Brønsted Acid Site ◽  
Brönsted Acid ◽  
Propane Cracking
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