scholarly journals Fabrication of the Hierarchical HZSM-5 Membrane with Tunable Mesoporosity for Catalytic Cracking of n-Dodecane

Catalysts ◽  
2019 ◽  
Vol 9 (2) ◽  
pp. 155 ◽  
Author(s):  
Zhenheng Diao ◽  
Lushi Cheng ◽  
Xu Hou ◽  
Di Rong ◽  
Yanli Lu ◽  
...  
Keyword(s):  
Catalytic Cracking ◽  
Inductively Coupled Plasma ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Inductively Coupled ◽  
Swelling Agent ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Adsorption Desorption

Hierarchical HZSM-5 membranes were prepared on the inner wall of stainless steel tubes, using amphiphilic organosilane (TPOAC) and mesitylene (TMB) as a meso-porogen and a swelling agent, respectively. The mesoporosity of the HZSM-5 membranes were tailored via formulating the TPOAC/Tetraethylorthosilicate (TPOAC/TEOS) ratio and TMB/TPOAC ratio, in synthesis gel, and the prepared membranes were systematically characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), N2 adsorption–desorption, N2 permeation, inductively coupled plasma (ICP), in situ fourier transform infrared (FT-IR), ammonia temperature-programmed desorption (NH3-TPD), etc. It was found that the increase of the TPOAC/TEOS ratio promoted a specific surface area and diffusivity of the HZSM-5 membranes, as well as decreased acidity; the increase of the TMB/TPOAC ratios led to an enlargement of the mesopore size and diffusivity of the membranes, but with constant acid properties. The catalytic performance of the prepared HZSM-5 membranes was tested using the catalytic cracking of supercritical n-dodecane (500 °C, 4 MPa) as a model reaction. The hierarchical membrane with the TPOAC/TEOS ratio of 0.1 and TMB/TPOAC ratio of 2, exhibited superior catalytic performances with the highest activity of up to 13% improvement and the lowest deactivation rate (nearly a half), compared with the microporous HZSM-5 membrane, due to the benefits of suitable acidity, together with enhanced diffusivity of n-dodecane and cracking products.

scholarly journals Generalized Methodology for Inserting Metal Heteroatoms into the Layered Zeolite Precursor RUB-36 by Interlayer Expansion

Crystals ◽  
2020 ◽  
Vol 10 (6) ◽  
pp. 530 ◽  
Author(s):  
Chaoqun Bian ◽  
Xiao Wang ◽  
Lan Yu ◽  
Fen Zhang ◽  
Jie Zhang ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Zeolite Sample ◽  
X Ray ◽  
Inductively Coupled ◽  
Temperature Programmed ◽  
First Time ◽  
N2 Sorption

The incorporation of metal heteroatoms into zeolites is an effective modification strategy for enhancing their catalytic performance. Herein, for the first time we report a generalized methodology for inserting metal heteroatoms (such as Sn, Fe, Zn, and Co) into the layered zeolite precursor RUB-36 via interlayer expansion by using the corresponding metal acetylacetate salt. Through this generalized methodology, Sn-JHP-1, Fe-JHP-1, Zn-JHP-1 and Co-JHP-1 zeolites could be successfully prepared by the reaction of RUB-36 and corresponding metal acetylacetate salt at 180 °C for 24 h in the presence of HCl solution. As a typical example, Sn-JHP-1 and calcined Sn-JHP-1 (Sn-JHP-2) zeolite is well characterized by the X-ray diffraction (XRD), diffuse reflectance ultraviolet-visible (UV-Vis), inductively coupled plasma (ICP), N2 sorption, temperature-programmed-desorption of ammonia (NH3-TPD) and X-ray photoelectron spectroscopy (XPS) techniques, which confirm the expansion of adjacent interlayers and thus the incorporation of isolated Sn sites within the zeolite structure. Notably, the obtained Sn-JHP-2 zeolite sample shows enhanced catalytic performance in the conversion of glucose to levulinic acid (LA) reaction.

The Characteristic Evaluation of Hydroxyapatite Powders Synthesized from CaCO3 Refined from Oyster Shell and H3PO4

2006 ◽  
Vol 118 ◽  
pp. 639-644
Author(s):  
Hye Sung Kim ◽  
Su Chak Ryu
Keyword(s):  
Bone Density ◽  
Inductively Coupled Plasma ◽  
Oyster Shell ◽  
Atomic Emission ◽  
Xrd Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled ◽  
Infra Red ◽  
Ft Ir

Hydroxyapatite (Ca10(PO4)6(OH)2, HAp) powders is synthesized using the mixed powders of CaCO3 refined from oyster shells and phosphoric acid (H3PO4-98%, Daejung) as starting materials. The characteristic evaluation and chemical analysis of the synthesized powders is performed by X-ray diffraction (XRD), Fourier-transformed infra-red spectroscopy (FT-IR), and inductively-coupled plasma atomic emission spectroscopy (ICPAES). XRD analysis of synthetic powder by heat treatment at 1300°C for 2hrs shows only HAp peaks corresponding to stoichiometric HAp. It is confirmed by ICP-AES test that impurities such as Zn, In, Ti, Ba, Cd, Pb, and Mn, is not detected at all, but small amounts of Ti and Be is observed (0.099ppm Ti and 0.002ppm Ba). Variation of bone density is measured by giving medication of HAp powder with drinking water into human body continuously for three month. After the medication, the bone density is higher than the medication before. This means that HAp powder made from this process can be used as improver of bone density.

scholarly journals “PdO vs. PtO”—The Influence of PGM Oxide Promotion of Co3O4 Spinel on Direct NO Decomposition Activity

Catalysts ◽  
2019 ◽  
Vol 9 (1) ◽  
pp. 62 ◽  
Author(s):  
Gunugunuri K. Reddy ◽  
Torin C. Peck ◽  
Charles A. Roberts
Keyword(s):  
Photoelectron Spectroscopy ◽  
No Decomposition ◽  
Single Element ◽  
X Ray Diffraction ◽  
X Ray ◽  
Promotional Effect ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Thermal Stability Of

Direct decomposition of NO into N2 and O2 (2NO→N2 + O2) is recognized as the “ideal” reaction for NOx removal because it needs no reductant. It was reported that the spinel Co3O4 is one of the most active single-element oxide catalysts for NO decomposition at higher reaction temperatures, however, activity remains low below 650 °C. The present study aims to investigate new promoters for Co3O4, specifically PdO vs. PtO. Interestingly, the PdO promoter effect on Co3O4 was much greater than the PtO effect, yielding a 4 times higher activity for direct NO decomposition at 650 °C. Also, Co3O4 catalysts with the PdO promoter exhibit higher selectivity to N2 compared to PtO/Co3O4 catalysts. Several characterization measurements, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), H2-temperature programmed reduction (H2-TPR), and in situ FT-IR, were performed to understand the effect of PdO vs. PtO on the properties of Co3O4. Structural and surface analysis measurements show that impregnation of PdO on Co3O4 leads to a greater ease of reduction of the catalysts and an increased thermal stability of surface adsorbed NOx species, which contribute to promotion of direct NO decomposition activity. In contrast, rather than remaining solely as a surface species, PtO enters the Co3O4 structure, and it promotes neither redox properties nor NO adsorption properties of Co3O4, resulting in a diminished promotional effect compared to PdO.

scholarly journals Fe-Containing MOFs as Seeds for the Preparation of Highly Active Fe/Al-SBA-15 Catalysts in the NAlkylation of Aniline

Molecules ◽  
2019 ◽  
Vol 24 (15) ◽  
pp. 2695 ◽  
Author(s):  
Mhadmhan ◽  
Marquez-Medina ◽  
Romero ◽  
Reubroycharoen ◽  
Luque
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Catalytic Performance ◽  
Alkylation Reaction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Inductively Coupled ◽  
Highly Active ◽  
Milling Method ◽  
Plasma Mass Spectrometry

We have successfully incorporated iron species into mesoporous aluminosilicates (AlSBA15) using a simple mechanochemical milling method. The catalysts were characterized by nitrogen physisorption, inductively coupled plasma mass spectrometry (ICP-MS), pyridine (PY) and 2,6-dimethylpyridine (DMPY) pulse chromatography titration, powder X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy with energy-dispersive X-ray spectroscopy (SEM-EDX). The catalysts were tested in the N-alkylation reaction of aniline with benzyl alcohol for imine production. According to the results, the iron sources, acidity of catalyst and reaction conditions were important factors influencing the reaction. The catalyst showed excellent catalytic performance, achieving 97% of aniline conversion and 96% of imine selectivity under optimized conditions.

The Application of Mesoporous ZSM-5 Zeolite in the ULSD Catalysts

2020 ◽  
Vol 4 (4) ◽  
pp. 1-3
Author(s):  
Liu L
Keyword(s):  
Catalytic Performance ◽  
Nitrogen Compounds ◽  
In Situ Ftir ◽  
X Ray Diffraction ◽  
N2 Adsorption ◽  
X Ray ◽  
Acidic Sites ◽  
Adsorption Desorption ◽  
Al2o3 Catalyst

The mesoporous ZSM-5 zeolite containing MoCoP/Al2O3 catalyst (C12-ZSM5) with the mixture of Al2O3 and mesoporous ZSM- 5 zeolite as carrier was synthesized. The catalytic performance of C12-ZSM5 catalyst was evaluated by the hydrodesulfurization (HDS) of different diesel feedstock. The carriers and catalysts were characterized by N2 adsorption-desorption, pyridine-FTIR, X-ray diffraction (XRD) and CO in-situ FTIR (CO-FTIR) techniques. Results showed that mesoporous ZSM-5 can improve the acidity of the catalyst and increase the number of MoCoS active phases. The C12-ZSM5 catalyst had low HDS and HDN activity, because the acidic sites of mesoporous ZSM-5 were easily occupied by nitrogen compounds. The HDS activity of C12-ZSM5 catalyst was fully exploited by using graded packing technology, the sulfur content of product oil was 5.9 ng/μL. The relative HDS activity of C12-ZSM5 catalyst is 1.47 times that of FHUDS-8 catalyst.

The Different Morphology of Co3O4 Catalysts and Application in the Abatement of Carbon Monoxide

2021 ◽  
Vol 21 (12) ◽  
pp. 6082-6087
Author(s):  
Chih-Wei Tang ◽  
Hsiang-Yu Shih ◽  
Ruei-Ci Wu ◽  
Chih-Chia Wang ◽  
Chen-Bin Wang
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Co Oxidation ◽  
Nitrogen Adsorption ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Adsorption Desorption

The increase of harmful carbon monoxide (CO) caused by incomplete combustion can affect human health even lead to suffocation. Therefore reducing the CO discharged by vehicles or factories is urgent to improve the air quality. The spinel cobalt (II, III) oxide (Co3O4) is an active catalyst for CO abatement. In this study, we tried to fabricate dispersing Co3O4 via the dispersion-precipitation method with acetic acid, formic acid, and oxalic acid as the chelating dispersants. Then, the asprepared samples were calcined at 300 ºC for 4 h to obtain active catalysts, and assigned as Co(A), Co(F) and Co(O) respectively, the amount of the dispersants used are labeled as I (0.12 mole), II (0.03 mole) and III (0.01 mole). For comparison, another CoAP sample was prepared via alkaliinduced precipitation and calcined at 300 ºC. All samples were characterized by X-ray diffraction (XRD), temperature-programmed reduction (TPR), scanning electron microscope (SEM), and nitrogen adsorption/desorption system, and the catalytic activity focused on the CO oxidation. The influence of chelating dispersant on the performance of abatement of CO was pursued in this study. Apparently, the results showed that the chelating dispersant can influence the catalytic activity of CO abatement. An optimized ratio of dispersant can improve the performance, while excess dispersant lessens the surface area and catalytic performance. The series of Co(O) samples can easily donate the active oxygen since the labile Co–O bonding and indicated the preferential performance than both Co(A) and Co(F) samples. The nanorod Co(O)-II showed preferential for CO oxidation, T50 and T90 approached 96 and 127 ºC, respectively. Also, the favorable durability of Co(O)-II sample maintains 95% conversion still for 50 h at 130 ºC and does not emerge deactivation.

Synthesis and Characterization of Bismuth Nickel Tantalate Pyrochlore

2015 ◽  
Vol 749 ◽  
pp. 30-35 ◽  
Author(s):  
Asiah Abdullah ◽  
Wan Elina Faradilla Wan Khalid ◽  
Siti Zaubidah Abdullah
Keyword(s):  
Inductively Coupled Plasma ◽  
Single Phase ◽  
Atomic Emission ◽  
Emission Spectrometry ◽  
X Ray Diffraction ◽  
Plasma Atomic Emission Spectrometry ◽  
Inductively Coupled ◽  
Cubic System ◽  
Ft Ir ◽  
Single Phase Material

Bi3Ni2Ta3O14 pyrochlores and related materials were prepared by solid state reaction at sintering temperatures ranging from 900°C to 1150°C. The BNT cubic pyrochlores could be represented by a general formula Bi3Ni2-xTa3O14-x and phase pure sample was obtained at temperature 1050°C with x = 0.6. This was confirmed by X-ray diffraction analysis and detailed lattice refinement. The single phase material crystallized in a cubic system, space group Fd3m with a = b = c = 10.5134 Å, α = β = γ = 90o, respectively. The sample was further characterized using a combination of techniques including Fourier-Transform infrared spectroscopy (FT-IR), differential thermal analysis (DTA), thermogravimetric analysis (TGA) and inductively coupled plasma – atomic emission spectrometry (ICP-AES). The material was thermally stable without any thermal events being observed. Electrical properties of the single phase material were studied by ac impedance spectroscopy starting from room temperature to 800 oC over a frequency range of 5 Hz to 13 MHz. The phase formation and solid solutions of cubic pyrochlores in the Bi2O3-NiO-Ta2O5 (BNT) ternary system were studied thoroughly via combination of characterization techniques.

Rice Straw and Rice Straw Ash as Precursor for Synthesis of Mesoporous Molecular Sieves MCM-41

2012 ◽  
Vol 550-553 ◽  
pp. 1391-1394
Author(s):  
Xiao Hong Tang ◽  
Bao Jun Li ◽  
Cheng Wei Li
Keyword(s):  
Rice Straw ◽  
Molecular Sieves ◽  
Mesoporous Structure ◽  
Mesoporous Molecular Sieves ◽  
X Ray Diffraction ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Straw Ash ◽  
Mcm 41

In this paper, rice straw (RS) and rice straw ash (RSA) were employed to synthesize mesoporous molecular sieves MCM-41 in an open-vessel. The structure of as-synthesized MCM-41 was characterized by X-ray diffraction (XRD) pattern, Fourier transform infrared (FT–IR) spectrum, NH3-Temperature Programmed Desorption (TPD), and N2 adsorption-desorption isotherms. RS-MCM-41 and RSA-MCM-41 possess the same typical hexagonal mesoporous structure with high long-range order and crystalline degree as those of MCM-41 from water glass (SDS-MCM-41).

Nanoparticles of Ni-Co Alloy Derived from Layered Double Hydroxides and Their Catalytic Performance for CO Methanation

NANO ◽  
2016 ◽  
Vol 11 (10) ◽  
pp. 1650118 ◽  
Author(s):  
Jingge Liu ◽  
Ang Cao ◽  
Jing Si ◽  
Lihong Zhang ◽  
Qinglan Hao ◽  
...  
Keyword(s):  
Metallic Nanoparticles ◽  
Carbon Deposition ◽  
Catalytic Performance ◽  
X Ray Diffraction ◽  
Co Methanation ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
The Stability ◽  
Double Hydroxides ◽  
Adsorption Desorption

Sintering of the active metallic nanoparticles and carbon deposition are the key problems faced for CO methanation catalysts. For overcoming those problems, bimetallic nanocatalyst is a promising route. In this work, a series of Al2O3 supported Ni-Co alloy catalysts were prepared by reducing NiCoAl layered double hydrotalcite (LDHs), and characterized with X-ray diffraction (XRD), temperature programmed reduction TPR, N2 adsorption-desorption, transmission electron microscopy (TEM) and temperature programed oxidation (TPO) techniques. The resultant catalysts were mesoporous with nanoparticles of Ni-Co alloy ranging from 7.9[Formula: see text]nm to 9.2[Formula: see text]nm which were highly dispersed in alumina matrix. The sample Ni7Co3-Al2O3 catalysts showed very good catalytic performance during the stability test at 500/600[Formula: see text]C for 300[Formula: see text]h, meanwhile exhibited excellent anti-sintering ability and anti-carbon deposition ability, owing to the formation of Ni-Co alloy and the feature of LDHs. This strategy for improving anti-sintering and anti-carbon deposition should be extendable for catalysts of other reactions.

Catalytic Transfer Hydrogenolysis of 2-Phenyl-2-Propanol with Pd/C and Formic Acid

2011 ◽  
Vol 287-290 ◽  
pp. 1749-1752 ◽  
Author(s):  
Jian Feng ◽  
Wei Xiong ◽  
Yun Jia ◽  
Jin Bo Wang ◽  
De Rong Liu ◽  
...  
Keyword(s):  
Formic Acid ◽  
Inductively Coupled Plasma ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Reaction Conditions ◽  
New Approach ◽  
Inductively Coupled ◽  
Transmission Electron ◽  
Catalytic Transfer ◽  
Adsorption Desorption

The catalytic transfer hydrogenolysis of 2-phenyl-2-propanol was studied over Pd/C catalyst, using formic acid and formate salts as hydrogen donors. The Pd/C catalyst was characterized by powder X-ray diffraction (XRD), inductively coupled plasma (ICP), N2 adsorption/desorption and transmission electron microscopy (TEM). The effects of hydrogen donor, molar ratio of formic acid to 2-phenyl-2-propanol and water content were evaluated. Under mild reaction conditions (80 °C, 2h), 2-phenyl-2-propanol can be hydrogenolyzed to isopropylbenzene with very high selectivity (96.5%) and high conversion (92.8%) in the presence of Pd/C and formic acid. From the viewpoint of environmental friendly principles, this study may open the way to a new approach for the production of propylene oxide.

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