Tailoring the physicochemical properties of zeolite catalysts

2014 ◽  
Vol 4 (11) ◽  
pp. 3762-3771 ◽  
Author(s):  
J. D. Rimer ◽  
M. Kumar ◽  
R. Li ◽  
A. I. Lupulescu ◽  
M. D. Oleksiak
Keyword(s):  
Physicochemical Properties ◽  
Surface Science ◽  
Zeolite Catalysts ◽  
Crystal Habit ◽  
Zeolite Synthesis ◽  
Zeolite Surface ◽  
Control Crystallization

Here we summarize our recent findings in the area of zeolite synthesis, focusing on pathways to control crystallization in the absence of organics, tailoring crystal habit with growth modifiers, and pioneering techniques in zeolite surface science to elucidate the mechanisms of growth.

scholarly journals The Influence of Ce or Mn Doping on Cu-Based Catalysts for De-NOx with NH3-SCR

2020 ◽  
Vol 2020 ◽  
pp. 1-8 ◽  
Author(s):  
Lei Jiang ◽  
Yixi Cai ◽  
Miaomiao Jin ◽  
Zengzan Zhu ◽  
Yinhuan Wang
Keyword(s):  
Low Temperature ◽  
Physicochemical Properties ◽  
Topological Structure ◽  
Zeolite Catalysts ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Performance Tests ◽  
Nh3 Scr ◽  
Temperature Window ◽  
Different Doses

In this study, the de-NOx performance of Cu-based zeolite catalysts supported on topological structure (SSZ-13, BEA, ZSM-5) and loaded with different doses of copper (from 2 to 6 wt.%) was investigated. The preparation of copper-based catalysts adopted the incipient wetness impregnation method. To analyze the physicochemical properties of the catalysts, advanced techniques like BET, XRD, NH3-TPD, H2-TPR, and DRS UV-Vis were used. The performance tests suggested the 4Cu/SSZ-13 catalyst exhibited higher low-temperature activity and wider temperature window. Furthermore, compared with Mn-Cu/SSZ-13, the Ce-Cu/SSZ-13 catalysts exhibited better de-NOx performance.

ChemInform Abstract: Tailoring the Physicochemical Properties of Zeolite Catalysts

ChemInform ◽  
2014 ◽  
Vol 45 (51) ◽  
pp. no-no ◽  
Author(s):  
J. D. Rimer ◽  
M. Kumar ◽  
R. Li ◽  
A. I. Lupulescu ◽  
M. D. Oleksiak
Keyword(s):  
Physicochemical Properties ◽  
Zeolite Catalysts

Activity and physicochemical properties of Fe-zeolite catalysts for SCR of N2o with CH4

2005 ◽  
Vol 86 (2) ◽  
pp. 363-370 ◽  
Author(s):  
M. Shimokawabe ◽  
T. Chaki ◽  
S. Ozawa ◽  
M. Arai
Keyword(s):  
Physicochemical Properties ◽  
Zeolite Catalysts

scholarly journals The impact of the hydrodechlorination process on the physicochemical properties of bimetallic Ag-CuBeta zeolite catalysts

2017 ◽  
Vol 243 ◽  
pp. 56-64 ◽  
Author(s):  
A. Śrębowata ◽  
Izabela I. Kamińska ◽  
S. Casale ◽  
D. Brouri ◽  
C. Calers ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Zeolite Catalysts ◽  
The Impact

scholarly journals Methanol-to-olefins process over zeolite catalysts with DDR topology: effect of composition and structural defects on catalytic performance

2016 ◽  
Vol 6 (8) ◽  
pp. 2663-2678 ◽  
Author(s):  
Irina Yarulina ◽  
Joris Goetze ◽  
Canan Gücüyener ◽  
Leonard van Thiel ◽  
Alla Dikhtiarenko ◽  
...  
Keyword(s):  
Physicochemical Properties ◽  
Catalyst Deactivation ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Structural Defects ◽  
Ethylene Propylene ◽  
Mto Reaction ◽  
Sigma 1 ◽  
Olefin Selectivity

The effect of physicochemical properties on catalyst deactivation, overall olefin selectivity and ethylene/propylene ratio during the methanol-to-olefins (MTO) reaction is presented for two zeolites with the DDR topology, Sigma-1 and ZSM-58.

UHV-TEM studies of laser-induced damage

1991 ◽  
Vol 49 ◽  
pp. 632-633
Author(s):  
T.S. Savage ◽  
R. Ai ◽  
D. Dunn ◽  
L.D. Marks
Keyword(s):  
Surface Science ◽  
Rapid Heating ◽  
Local Heating ◽  
Routine Practice ◽  
Transmission Electron ◽  
Northwestern University ◽  
Laser Induced Damage ◽  
Set Up ◽  
Focusing Lens ◽  
Diffusion Of Impurities

The use of lasers for surface annealing, heating and/or damage has become a routine practice in the study of materials. Lasers have been closely looked at as an annealing technique for silicon and other semiconductors. They allow for local heating from a beam which can be focused and tuned to different wavelengths for specific tasks. Pulsed dye lasers allow for short, quick bursts which can allow the sample to be rapidly heated and quenched. This short, rapid heating period may be important for cases where diffusion of impurities or dopants may not be desirable.At Northwestern University, a Candela SLL - 250 pulsed dye laser, with a maximum power of 1 Joule/pulse over 350 - 400 nanoseconds, has been set up in conjunction with a Hitachi UHV-H9000 transmission electron microscope. The laser beam is introduced into the surface science chamber through a series of mirrors, a focusing lens and a six inch quartz window.

Preparation and characterisation of vanadium pentoxide supported rhodium catalyst

1988 ◽  
Vol 46 ◽  
pp. 946-947
Author(s):  
A. Legrouri
Keyword(s):  
Aqueous Solution ◽  
Thermal Decomposition ◽  
Physicochemical Properties ◽  
Surface Area ◽  
Vanadium Pentoxide ◽  
High Purity ◽  
Gas Adsorption ◽  
Rhodium Catalyst ◽  
Optical Methods ◽  
Reducible Oxides

The industrial importance of metal catalysts supported on reducible oxides has stimulated considerable interest during the last few years. This presentation reports on the study of the physicochemical properties of metallic rhodium supported on vanadium pentoxide (Rh/V2O5). Electron optical methods, in conjunction with other techniques, were used to characterise the catalyst before its use in the hydrogenolysis of butane; a reaction for which Rh metal is known to be among the most active catalysts.V2O5 powder was prepared by thermal decomposition of high purity ammonium metavanadate in air at 400 °C for 2 hours. Previous studies of the microstructure of this compound, by HREM, SEM and gas adsorption, showed it to be non— porous with a very low surface area of 6m2/g3. The metal loading of the catalyst used was lwt%Rh on V2Q5. It was prepared by wet impregnating the support with an aqueous solution of RhCI3.3H2O.

Quantitative surface damage studies by H.R.E.M.

1989 ◽  
Vol 47 ◽  
pp. 632-633
Author(s):  
S. R. Singh ◽  
H. J. Fan ◽  
L. D. Marks
Keyword(s):  
Solar Wind ◽  
Quantitative Analysis ◽  
Surface Science ◽  
Surface Damage ◽  
Space Environment ◽  
Oxygen Desorption ◽  
The Past ◽  
Diffusion Controlled ◽  
Original Observation ◽  
Substantial Interest

Since the original observation that the surfaces of materials undergo radiation damage in the electron microscope similar to that observed by more conventional surface science techniques there has been substantial interest in understanding these phenomena in more detail; for a review see. For instance, surface damage in a microscope mimics damage in the space environment due to the solar wind and electron beam lithographic operations.However, purely qualitative experiments that have been done in the past are inadequate. In addition, many experiments performed in conventional microscopes may be inaccurate. What is needed is careful quantitative analysis including comparisons of the behavior in UHV versus that in a conventional microscope. In this paper we will present results of quantitative analysis which clearly demonstrate that the phenomena of importance are diffusion controlled; more detailed presentations of the data have been published elsewhere.As an illustration of the results, Figure 1 shows a plot of the shrinkage of a single, roughly spherical particle of WO3 versus time (dose) driven by oxygen desorption from the surface.

Advances in ultramicrotomy for physical sciences applications

1993 ◽  
Vol 51 ◽  
pp. 710-711
Author(s):  
G. McMahon ◽  
T. Malis
Keyword(s):  
Particle Surface ◽  
Zeolite Catalysts ◽  
Physical Sciences ◽  
Pull Out ◽  
Large Particles ◽  
Novel Applications ◽  
Metal Wires ◽  
Frequent Problem ◽  
Specific Orientation ◽  
Diamond Knife

As with all techniques which are relatively new and therefore underutilized, diamond knife sectioning in the physical sciences continues to see both developments of the technique and novel applications.Technique Developments Development of specific orientation/embedding procedures for small pieces of awkward shape is exemplified by the work of Bradley et al on large, rather fragile particles of nuclear waste glass. At the same time, the frequent problem of pullout with large particles can be reduced by roughening of the particle surface, and a proven methodology using a commercial coupling agent developed for glasses has been utilized with good results on large zeolite catalysts. The same principle (using acid etches) should work for ceramic fibres or metal wires which may only partially pull out but result in unacceptably thick sections. Researchers from the life sciences continue to develop aspects of embedding media which may be applicable to certain cases in the physical sciences.

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