scholarly journals Surrounded catalysts prepared by ion-exchange inverse loading

2020 ◽  
Vol 6 (20) ◽  
pp. eaay7031
Author(s):  
Panpan Hao ◽  
Mingjiang Xie ◽  
Shanyong Chen ◽  
Muhong Li ◽  
Feifei Bi ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Supported Catalysts ◽  
Critical Role ◽  
Supported Catalyst ◽  
Active Phase ◽  
Interfacial Interaction ◽  
Ion Exchange Reaction ◽  
Physical Isolation ◽  
Active Core ◽  
Catalytic Performances

The supported catalyst featuring highly dispersed active phase on support is the most important kind of industrial catalyst. Extensive research has demonstrated the critical role (in catalysis) of the interfacial interaction/perimeter sites between the active phase and support. However, the supported catalyst prepared by traditional methods generally presents low interface density because of limit contact area. Here, an ion-exchange inverse loading (IEIL) method has been developed, in which the precursor of support is controllably deposited onto the precursor of active phase by ion-exchange reaction, leading to an active core surrounded (by support) catalyst with various structures. The unique surrounded structure presents not only high interface density and mutually changed interface but also high stability due to the physical isolation of active phase, revealing superior catalytic performances to the traditional supported catalysts, suggesting the great potential of this new surrounded catalyst as the upgrade of supported catalyst in heterogeneous catalysis.

Facing the challenge of 2017: beet juice and ion exchange based softening technologies

2014 ◽  
pp. 745-749 ◽  
Author(s):  
Marlene Beyerle ◽  
François Rousset ◽  
Nicolas-Julian Hilbold
Keyword(s):  
Ion Exchange ◽  
Critical Role ◽  
Regeneration System ◽  
Associated Production ◽  
Combined Use ◽  
Common Ion

This article will review common ion exchange-based softening technologies, describing how the most popular of them, the New Regeneration System (NRS) process, might be a key answer in facing the changes coming in 2017. The process’s principles and advantages will be explained, as well as the associated production-regeneration sequence. The combined use of additional technologies can play a critical role as well, and this article will demonstrate how the integration of additional technologies – in this case chromatography – can increase competitiveness.

Photoassisted Production of O2-• and H2 in Aqueous Medium Stimulated by Polythiophene in ZSM-5 Zeolite Channels

1999 ◽  
Vol 64 (1) ◽  
pp. 149-156 ◽  
Author(s):  
Gabriel Čík ◽  
František Šeršeň ◽  
Alena Bumbálová
Keyword(s):  
Reactive Oxygen Species ◽  
Ion Exchange ◽  
Visible Light ◽  
Aqueous Medium ◽  
Exchange Reaction ◽  
Epr Spectroscopy ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Water Reduction ◽  
Ion Exchange Reaction

The formation of reactive oxygen species due to irradiation by a visible light of the polythiophene deposited in ZSM-5 zeolite channels in aqueous medium has been studied. Polymerization of thiophene was carried out in zeolite channels after the ion-exchange reaction of Na+ for Fe3+. By means of EPR spectroscopy, the temporarily generated 1O2 in irradiated aqueous medium was proved. The formation of O2-• was confirmed by the reduction of Fe3+-cytochrome c. Irradiation led to the water reduction to hydrogen.

Insight into the enhanced photocatalytic properties of AgBr/Ag4P2O7 composites synthesized via in situ ion exchange reaction

2021 ◽  
Vol 9 (1) ◽  
pp. 104889
Author(s):  
Wyllamanney da S. Pereira ◽  
Fabrício B. Destro ◽  
Cipriano B. Gozzo ◽  
Edson R. Leite ◽  
Júlio C. Sczancoski
Keyword(s):  
Ion Exchange ◽  
Exchange Reaction ◽  
Photocatalytic Properties ◽  
Ion Exchange Reaction ◽  
Insight Into

scholarly journals Experimental and Theoretical Studies of Sonically Prepared Cu–Y, Cu–USY and Cu–ZSM-5 Catalysts for SCR deNOx

Catalysts ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 824
Author(s):  
Przemysław J. Jodłowski ◽  
Izabela Czekaj ◽  
Patrycja Stachurska ◽  
Łukasz Kuterasiński ◽  
Lucjan Chmielarz ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Ultrasonic Irradiation ◽  
Active Phase ◽  
Spectroscopic Studies ◽  
In Situ Drifts ◽  
Ft Ir ◽  
Diffuse Reflectance Infrared ◽  
Experimental And Theoretical Studies

The objective of our study was to prepare Y-, USY- and ZSM-5-based catalysts by hydrothermal synthesis, followed by copper active-phase deposition by either conventional ion-exchange or ultrasonic irradiation. The resulting materials were characterized by XRD, BET, SEM, TEM, Raman, UV-Vis, monitoring ammonia and nitrogen oxide sorption by FT-IR and Diffuse Reflectance Infrared Fourier Transform Spectroscopy (DRIFTS). XRD data confirmed the purity and structure of the Y/USY or ZSM-5 zeolites. The nitrogen and ammonia sorption results indicated that the materials were highly porous and acidic. The metallic active phase was found in the form of cations in ion-exchanged zeolites and in the form of nanoparticle metal oxides in sonochemically prepared catalysts. The latter showed full activity and high stability in the SCR deNOx reaction. The faujasite-based catalysts were fully active at 200–400 °C, whereas the ZSM-5-based catalysts reached 100% activity at 400–500 °C. Our in situ DRIFTS experiments revealed that Cu–O(NO) and Cu–NH3 were intermediates, also indicating the role of Brønsted sites in the formation of NH4NO3. Furthermore, the results from our experimental in situ spectroscopic studies were compared with DFT models. Overall, our findings suggest two possible mechanisms for the deNOx reaction, depending on the method of catalyst preparation (i.e., conventional ion-exchange vs. ultrasonic irradiation).

scholarly journals Possibility of Superconductivity in a Layered Perovskite Niobate, KCa2Nb3O10, Synthesized by an Ion Exchange Reaction

2006 ◽  
Vol 114 (1334) ◽  
pp. 861-865 ◽  
Author(s):  
Sachi TAKEZAWA ◽  
Takashi TERANISHI ◽  
Hironori ISHIKAWA ◽  
Toshiaki TOKUMITSU ◽  
Kenji TODA ◽  
...  
Keyword(s):  
Ion Exchange ◽  
Exchange Reaction ◽  
Layered Perovskite ◽  
Ion Exchange Reaction

Top-down fabrication of Ti doped BiVO4 nanosheets for efficient water oxidation under visible light

2021 ◽  
Author(s):  
Bei Peng ◽  
Yawen Shi ◽  
Xin Zhang ◽  
Peiwen Lv
Keyword(s):  
Solid State ◽  
Ion Exchange ◽  
Visible Light ◽  
Exchange Reaction ◽  
Solid State Reaction ◽  
Water Oxidation ◽  
Photocatalytic Properties ◽  
Top Down ◽  
Ion Exchange Reaction

BiVO4 is one of the fascinating materials with excellent photocatalytic properties. A top-down approach composed of solid state reaction and ion exchange reaction is introduced to fabricate Ti doped BiVO4...

ELUTION BEHAVIOR OF PHOSPHATE CONTAINED IN Mg/Fe AND Zn/Fe LAYERED DOUBLE HYDROXIDES

2012 ◽  
Vol 06 ◽  
pp. 156-161 ◽  
Author(s):  
Masashi Kurashina ◽  
Tomohiro Amatsu ◽  
Takaaki Ochi ◽  
Nozomi Ohigashi ◽  
Eiji Kanezaki
Keyword(s):  
Ion Exchange ◽  
Concentrate Solution ◽  
Sulfate Solution ◽  
Carbonate Solution ◽  
Solution Ph ◽  
Ion Exchange Reaction ◽  
Pseudo Second Order ◽  
Elution Behavior ◽  
Double Hydroxide ◽  
Double Hydroxides

Layered double hydroxide (LDH) is a layered hydroxide and exchangeable anion is intercalated in its interlayer. Application of the LDH as a controlled-release material of interlayer anions has become of interest, thus it is important to clarify the elution behavior of interlayer anions. We synthesized hydrogenphosphate-intercalated Mg / Fe and Zn / Fe LDH and elution of phosphate from these LDH were tested in deionized water, sodium chloride solution, sodium sulfate solution, and sodium carbonate solution. For Mg / Fe LDH, the amount of eluted phosphate increased with time and reached to maximum that increased as higher concentrate solution was used. The elution of phosphate from Mg / Fe LDH could be described by the pseudo second-order equation. This elution behavior was explained as ion-exchange reaction of phosphate with sulfate or carbonate in tested solution by means of kinetic simulation using Runge-Kutta method. In the eluted solution, metal ions contained in the LDH were detected and its amount depended on pH of the tested solution, that is, amounts of eluted Mg and Zn ions were small at higher pH (ca. 10) for Mg / Fe and Zn / Fe LDH respectively, but large amount of Zn ion was detected when 2.03 mol·l-1 carbonate solution (pH = 13) was used. Thus elution of phosphate was caused by two main reactions: ion exchange and decomposition of the LDH.

scholarly journals Surfactant-Free Colloidal Strategies for Highly Dispersed and Active Supported IrO2 Catalysts: Synthesis and Performance Evaluation for the Oxygen Evolution Reaction

2021 ◽  
Author(s):  
Francesco Bizzotto ◽  
Jonathan Quinson ◽  
Johanna Schröder ◽  
Alessandro Zana ◽  
Matthias Arenz
Keyword(s):  
Supported Catalysts ◽  
Active Phase ◽  
Carbon Support ◽  
Colloidal Dispersions ◽  
Catalyst Design ◽  
Transition Electron Microscopy ◽  
Highly Active ◽  
X Ray Scattering ◽  
And Performance ◽  
Transition Electron

Supported Ir oxide catalysts obtained from surfactant-free colloidal Ir nanoparticles (NPs) synthesized in alkaline methanol (MeOH), ethanol (EtOH), and ethylene glycol (EG) are investigated and compared. The comparison of independent techniques such as transition electron microscopy (TEM), small angle X-ray scattering (SAXS), and electrochemistry allows shedding light on the parameters that affect the dispersion of the active phase as well as the catalytic activity. The colloidal dispersions obtained are suitable to develop supported catalysts with little NP agglomeration on a carbon support leading to highly active catalysts with more than 400 A g<sup>-1</sup><sub>Ir</sub> reached at 1.5 V<sub>RHE</sub> for the OER. While the more common surfactant-free alkaline EG synthesis requires flocculation and re-dispersion leading to Ir loss, the main difference between methanol and ethanol as solvent is related to the dispersibility of the support material. The choice of the suitable monoalcohol determines the maximum achieved Ir loading on the support without detrimental particle agglomeration. This simple consideration on catalyst design can readily lead to significantly improved catalysts.

Ultrasensitive photoelectrochemical immunoassay for prostate-specific antigen based on silver nanoparticles-triggered ion-exchange reaction with ZnO/CdS nanorods

The Analyst ◽  
2021 ◽  
Author(s):  
Ling Zhu ◽  
Zipeng Yin ◽  
Zijian Lv ◽  
Mei-Jin Li ◽  
Dianping Tang
Keyword(s):  
Prostate Cancer ◽  
Silver Nanoparticles ◽  
Ion Exchange ◽  
Exchange Reaction ◽  
Prostate Specific Antigen ◽  
Specific Antigen ◽  
Cds Nanorods ◽  
Ion Exchange Reaction ◽  
Photoelectrochemical Immunoassay

Prostate-specific antigen (PSA), a glycoprotein that is most likely to cause prostate cancer, has attracted widespread attention in recent years due to its increasing threat to people's life and health....

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