Acid and aluminium modification of sepiolite and its application in FCC catalysis

Clay Minerals ◽  
2010 ◽  
Vol 45 (1) ◽  
pp. 15-22 ◽  
Author(s):  
Shu-Qin Zheng ◽  
Yong Han ◽  
Xiao-Hong Huang ◽  
Ya-Li Dai ◽  
Dong Qian ◽  
...  
Keyword(s):  
Pore Volume ◽  
Treatment Time ◽  
Treatment Temperature ◽  
Fluid Catalytic Cracking ◽  
Ion Concentration ◽  
X Ray Diffraction ◽  
Salt Treatment ◽  
Excellent Performance ◽  
X Ray ◽  
Fcc Catalysts

AbstractThe effects of acid and Al concentration, type of Al salt, treatment temperature and time of removal of Mg from sepiolite have been investigated, as has the use of modified sepiolite as an active fluid catalytic cracking (FCC) matrix. The samples were characterized by N2 adsorption and X-ray diffraction. Mg removal from sepiolite increased with increasing acid and Al ion concentration, treatment time and temperature. The temperature had the greatest impact on Mg removal. After acid and Al modification, 29% of the Mg was removed. When using the modified sepiolites as active matrices in FCC catalysts, the specific surface area, pore volume and mesoporous pore volume of the catalysts increased and they exhibited excellent performance in resisting the effects of heavy-metals as a result of the introduction of Mg oxide from the modified sepiolite.

Nanoporosity in Ceramics from Polymeric Precursors

1994 ◽  
Vol 346 ◽  
Author(s):  
A.W. Reid ◽  
B. Rand ◽  
R.J.P. Emsley
Keyword(s):  
Heat Treatment ◽  
Pore Volume ◽  
Heat Treatment Temperature ◽  
Gas Adsorption ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
Carbon Phase ◽  
Volume Increase ◽  
X Ray ◽  
Adsorption Analysis

ABSTRACTIt is shown that ceramics derived from polycarbosilane polymers may develop an open nanoporous network after heat treatment to a temperatures between 1300 and 1550°C in argon. The resulting SiC-based ceramics were characterised by N2 gas adsorption analysis and X-ray diffraction. The apparent surface area, and pore volume increase with increasing heat treatment temperature, reaching values of 170 m2g-1 and 0.12 cm3-1 respectively. The pore network develops as the SiC crystals grow and as carbon is ejected from the structure. It is thought that the porosity may reside within the carbon phase, but this remains to be confirmed.

In Situ X-Ray Diffraction Studies of Crystallization Growth Behavior in ZnO-Bi2O3-B2O3 Glass as a Route to Functional Optical Devices

MRS Advances ◽  
2018 ◽  
Vol 3 (11) ◽  
pp. 563-567 ◽  
Author(s):  
Quentin Altemose ◽  
Katrina Raichle ◽  
Brittani Schnable ◽  
Casey Schwarz ◽  
Myungkoo Kang ◽  
...  
Keyword(s):  
Heat Treatment ◽  
Glass Ceramics ◽  
Treatment Temperature ◽  
Crystal Phase ◽  
X Ray Diffraction ◽  
X Ray ◽  
In Situ Xrd ◽  
Dsc Measurements ◽  
Transmission Window

ABSTRACTTransparent optical ZnO–Bi2O3–B2O3 (ZBB) glass-ceramics were created by the melt quenching technique. In this work, a melt of the glass containing stoichiometric ratios of Zn/Bi/B and As was studied. Differential scanning calorimeter (DSC) measurements was used to measure the thermal behavior. VIS/NIR transmission measurements were used to determine the transmission window. X-ray diffraction (XRD) was used to determine crystal phase. In this study, we explore new techniques and report a detailed study of in-situ XRD of the ZBB composition in order to correlate nucleation temperature, heat treatment temperature, and heat treatment duration with induced crystal phase.

scholarly journals Microporous Materials Based on Norbornadiene-Based Cross-Linked Polymers

Polymers ◽  
2018 ◽  
Vol 10 (12) ◽  
pp. 1382 ◽  
Author(s):  
Dmitry Alentiev ◽  
Dariya Dzhaparidze ◽  
Natalia Gavrilova ◽  
Victor Shantarovich ◽  
Elena Kiseleva ◽  
...  
Keyword(s):  
Pore Volume ◽  
Total Pore Volume ◽  
Amorphous Polymers ◽  
Co2 Uptake ◽  
Wide Angle ◽  
X Ray Diffraction ◽  
Pd Catalysts ◽  
X Ray ◽  
Positron Annihilation Lifetime ◽  
Surface Areas

New microporous homopolymers were readily prepared from norbornadiene-2,5, its dimer and trimer by addition (vinyl) polymerization of the corresponding monomers with 60–98% yields. As a catalyst Pd-N-heterocyclic carbene complex or Ni(II) 2-ethylhexanoate activated with Na+[B(3,5-(CF3)2C6H3)4]− or methylaluminoxane was used. The synthesized polynorbornenes are cross-linked and insoluble. They are glassy and amorphous polymers. Depending on the nature of the catalyst applied, BET surface areas were in the range of 420–970 m2/g. The polymers with the highest surface area were obtained in the presence of Pd-catalysts from the trimer of norbornadiene-2,5. The total pore volume of the polymers varies from 0.39 to 0.79 cm3/g, while the true volume of micropores was 0.14–0.16 cm3/g according to t-plot. These polymers gave CO2 uptake from 1.2 to 1.9 mmol/g at 273 K and 1 atm. The porous structure of new polymers was also studied by means of wide-angle X-ray diffraction and positron annihilation lifetime spectroscopy.

scholarly journals Cloning, expression, purification, crystallization and preliminary X-ray diffraction of a lysine-specific permease fromPseudomonas aeruginosa

2014 ◽  
Vol 70 (10) ◽  
pp. 1362-1367 ◽  
Author(s):  
Emmanuel Nji ◽  
Dianfan Li ◽  
Declan A. Doyle ◽  
Martin Caffrey
Keyword(s):  
Metal Ion ◽  
Cell Volume Regulation ◽  
Ion Concentration ◽  
Size Exclusion ◽  
Substrate Selectivity ◽  
X Ray Diffraction ◽  
Unit Cell Parameters ◽  
X Ray ◽  
Cell Parameters ◽  
Exclusion Chromatography

The prokaryotic lysine-specific permease (LysP) belongs to the amino acid–polyamine–organocation (APC) transporter superfamily. In the cell, members of this family are responsible for the uptake and recycling of nutrients, for the maintenance of a constant internal ion concentration and for cell volume regulation. The detailed mechanism of substrate selectivity and transport of L-lysine by LysP is not understood. A high-resolution crystal structure would enormously facilitate such an understanding. To this end, LysP fromPseudomonas aeruginosawas recombinantly expressed inEscherichia coliand purified to near homogeneity by immobilized metal ion-affinity chromatography (IMAC) and size-exclusion chromatography (SEC). Hexagonal- and rod-shaped crystals were obtained in the presence of L-lysine and the L-lysine analogue L-4-thialysine by vapour diffusion and diffracted to 7.5 Å resolution. The diffraction data were indexed in space groupP21, with unit-cell parametersa= 169.53,b= 169.53,c= 290.13 Å, γ = 120°.

scholarly journals Influence of Mineral Admixtures on Corrosion Inhibition Effect of Nitrites

2018 ◽  
Vol 2018 ◽  
pp. 1-6 ◽  
Author(s):  
Mengna Yang ◽  
Junzhe Liu ◽  
Hui Wang ◽  
Yushun Li ◽  
Yanhua Dai ◽  
...  
Keyword(s):  
Fly Ash ◽  
Corrosion Inhibition ◽  
Ion Concentration ◽  
Mineral Admixtures ◽  
X Ray Diffraction ◽  
Nitrite Ion ◽  
X Ray ◽  
Inhibition Effect ◽  
Diffraction Patterns ◽  
Micro Analysis

Chemical quantitative analysis of effective anticorrosion component and micro-analysis of hydration products of fly ash and slag on the influence of the nitrites corrosion inhibition was studied by the free nitrite ion concentration and X-ray diffraction pattern. The free nitrite ion concentration was used to describe the corrosion inhibition effect of nitrites. And the X-ray diffraction patterns were used to analyze the adsorption properties. The research results show that fly ash and slag were beneficial for improving the corrosion inhibition effect of nitrites. Cement-based materials with slag at low content presented high free nitrite ion concentration, but the addition of low content of fly ash harmed the corrosion inhibition effect of nitrites. The specimens incorporated with both fly ash and slag can reach the highest free nitrite ion concentration when the compounding proportion was 1:1. It was concluded that the extent of mineral admixtures of the corrosion inhibition effect of nitrites was affected by its type and content.

The effects of thermal treatment on the nanomechanical behavior of bamboo (Phyllostachys pubescens Mazel ex H. de Lehaie) cell walls observed by nanoindentation, XRD, and wet chemistry

Holzforschung ◽  
2017 ◽  
Vol 71 (2) ◽  
pp. 129-135 ◽  
Author(s):  
Yanjun Li ◽  
Chengjian Huang ◽  
Li Wang ◽  
Siqun Wang ◽  
Xinzhou Wang
Keyword(s):  
Cell Wall ◽  
Thermal Treatment ◽  
Cell Walls ◽  
Treatment Time ◽  
Lignin Content ◽  
Phyllostachys Pubescens ◽  
X Ray Diffraction ◽  
Wet Chemistry ◽  
X Ray ◽  
Wet Chemical

Abstract The effects of thermal treatment of bamboo at 130, 150, 170, and 190°C for 2, 4, and 6 h were investigated in terms of changes in chemical composition, cellulose crystallinity, and mechanical behavior of the cell-wall level by means of wet chemical analysis, X-ray diffraction (XRD), and nanoindentation (NI). Particularly, the reduced elastic modulus (Er), hardness (H), and creep behavior were in focus. Both the temperature and treatment time showed significant effects. Expectedly, the hemicelluloses were degraded and the relative lignin content was elevated, while the crystallinity of the cellulose moiety was increased upon thermal treatment. The Er and H data of the cell wall were increased after 6 h treatment at 190°C, from 18.4 to 22.0 GPa and from 0.45 to 0.65 GPa, respectively. The thermal treatment led to a decrease of the creep ratio (CIT) under the same conditions by ca. 28%. The indentation strain state (εi) also decreased significantly after thermal treatment during the load-holding stage.

Research on Properties of Amorphous Cr-C Alloy Coating in Crystallization Evolution

2012 ◽  
Vol 184-185 ◽  
pp. 1175-1180
Author(s):  
Guo Liang Li ◽  
Xiao Hua Jie ◽  
Bi Xue Yang
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Intermetallic Compound ◽  
Adhesion Force ◽  
Alloy Coating ◽  
Treatment Temperature ◽  
X Ray Diffraction ◽  
X Ray ◽  
Proper Values ◽  
Peak Value

Amorphous Cr–C alloy coating was prepared by electrodepositing. The microhardness of the coating was tested after annealing from 100°C to 800°C and the crystallization evolution was studied by the analysis of X-ray diffraction (XRD) and differential scanning caborimetry (DSC). The results showed that the crystallization evolution of the coating began at 300°C and finished around 450°C, and intermetallic compound Cr7C3and Cr23C6appeared when heat treatment temperature reached around 600°C. The microhardness, corrosion resistance as well as the adhesion of the coating all increased first with the temperature and then dropped until it attained the proper values. The microhardness reached the maximum of 1610HV0.025at 600°C. While the corrosion resistance and the adhesion force attained the peak value at about 400°C.

Preparation of Iron Catalysts Generated from Fe-Coagulated Sludge Produced by Ferric Chloride Coagulation of Wastewater

2014 ◽  
Vol 1025-1026 ◽  
pp. 645-650
Author(s):  
Supranee Foowut ◽  
Tawanrat Palothaisit ◽  
Natthadabhorn Boonlor ◽  
Panida Prompinit ◽  
Pinsuda Viravathana
Keyword(s):  
Specific Surface ◽  
Pore Volume ◽  
Total Pore Volume ◽  
Iron Catalysts ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Co Precipitation ◽  
X Ray Absorption ◽  
Xanes Analysis

In this work, the FexOy catalysts were prepared by the co-precipitation method. The catalysts were characterized by X-ray diffraction (XRD), X-ray absorption spectroscopy (XAS), and Brunauer-Emmett-Teller (BET) surface analysis. From XRD results, the FexOy with the wastewater to coagulant ratio of 1:2 catalyst (FexOy-1:2) calcined at 600 °C for 6 h showed the presence of the wustite (FeO) form. XANES analysis showed the phase of FeO in FexOy-1:2 calcined at 600 °C for 6 h which corresponded to the result from XRD. The FexOy 1:1 catalyst had higher specific surface area and larger total pore volume compared to the FexOy 1:2 catalyst.

scholarly journals In-Situ Characterization by High-Energy X-ray Diffraction of the Phase Transformations Leading to Transformation-Induced Plasticity-Aided Bainitic Steel

2019 ◽  
Vol 3 (4) ◽  
pp. 25
Author(s):  
Zélie Tournoud ◽  
Frédéric De Geuser ◽  
Gilles Renou ◽  
Didier Huin ◽  
Patricia Donnadieu ◽  
...  
Keyword(s):  
Carbon Content ◽  
Phase Transformations ◽  
High Energy ◽  
Heat Treatments ◽  
Treatment Temperature ◽  
Bainitic Steel ◽  
X Ray Diffraction ◽  
Transformation Induced Plasticity ◽  
X Ray

The phase transformations occurring during the heat treatments leading to transformation-induced plasticity (TRIP)-aided bainitic steel have been investigated in-situ by high-energy X-ray diffraction (HEXRD) conducted with synchrotron light at 90 keV. Direct microstructure characterization has been performed by electron microscopy using electron backscatter diffraction and orientation and phase mapping in a transmission electron microscope. HEXRD data allow the quantification of the evolution of the austenite phase fraction with the heat treatments, as well as its carbon content and the fraction of carbides, from the lattice parameter evolution. It is shown that different combinations of austenite fraction and carbon content can be reached by adjusting the heat treatment temperature.

Formation of Aluminum Nitride Films by Gas Nitriding

2014 ◽  
Vol 625 ◽  
pp. 651-656 ◽  
Author(s):  
Masashi Yoshida ◽  
Zhou Tao ◽  
Noah Utsumi
Keyword(s):  
Aluminum Alloys ◽  
Aluminum Nitride ◽  
Electron Probe ◽  
Treatment Time ◽  
Film Surface ◽  
Nitride Film ◽  
X Ray Diffraction ◽  
Good Adhesion ◽  
X Ray ◽  
Gas Nitriding

In this study, aluminum alloys were subjected to nitriding at 823 K for 0–18.0 ks using alumina and magnesium powders for improving their radiation performance. After nitriding, aluminum nitride films were formed on the aluminum substrate. The thickness of the formed films varied from 1.5 to 11 μm, and the color of the film surface was dark brown or black. The thickness of the aluminum nitride film increased with an increase in the treatment time. X-ray diffraction and electron probe microanalysis results showed that the film was composed of aluminum nitride, alumina, aluminum, and magnesium. Further, the film showed good adhesion at 0 ks.

Sign in / Sign up

Export Citation Format

Share Document