Synthesis and Characterization of CuMnOx-Bentonite as Efficient Catalyst for Oxidation of m-xylene

2020 ◽  
Vol 42 (4) ◽  
pp. 504-504
Author(s):  
Mo Thi Nguyen Mo Thi Nguyen ◽  
Cam Minh Le Cam Minh Le ◽  
Tuan Minh Nguyen Tuan Minh Nguyen ◽  
Hao Hoang Nguyen Hao Hoang Nguyen ◽  
Anwar ul Haq Ali Shah Hung Van Hoang Anwar ul Haq Ali Shah Hung Van Hoang
Keyword(s):  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Catalytic Performance ◽  
Morphological Characterization ◽  
Efficient Catalyst ◽  
Tem Analysis ◽  
Different Temperatures ◽  
Ft Ir ◽  
Temperature Programmed ◽  
Xrd And Tem

Catalytic oxidation of organic volatile compounds (VOCs) is considered superior to conventional methods because very low concentration of VOCs can also be oxidized and removed at low temperatures without consumption of addditional fuel and introduction of NOx compounds into the environment. Herein, the synthesis of MnO2 nanoparticles on bentonite (Bent) support in the presence of CuO for catalytic oxidation of m-xylene is reported. The synthesized materials were analyzed with FT-IR, XRD, and TEM analysis for structural and morphological characterization. XRD and TEM analysis indicated the formation of δ-MnO2 with sheet structure on Bent surface. Temperature-programmed reduction (H2-TPR) of hydrogen was used to investigate catalytic performance of δ-MnO2 towards oxidation of m-xylene at different temperatures. The catalytic activity was strongly dependent on the δ-MnO2 content in the synthesized material. 100 % oxidation of m-xylene with observed with 10% Mn content at temperature below than 325 oC. Intersetingly introduction of CuO greatly improved the catalytic activity of Mn-Bent materials. The presence of Cu in Mn-Bent has greatly reduced the temperature for complete oxidation of m-xylene. In this case100% conversion of m-xylene was observed at 250 oC.

scholarly journals A diffusion anisotropy descriptor links morphology effects of H-ZSM-5 zeolites to their catalytic cracking performance

2021 ◽  
Vol 4 (1) ◽  
Author(s):  
Xiaoliang Liu ◽  
Jing Shi ◽  
Guang Yang ◽  
Jian Zhou ◽  
Chuanming Wang ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Catalytic Cracking ◽  
Catalytic Performance ◽  
Zeolite Catalysts ◽  
Time Resolved ◽  
Cracking Performance ◽  
Morphology Effect ◽  
Ft Ir ◽  
The Difference ◽  
Dynamics Simulations

AbstractZeolite morphology is crucial in determining their catalytic activity, selectivity and stability, but quantitative descriptors of such a morphology effect are challenging to define. Here we introduce a descriptor that accounts for the morphology effect in the catalytic performances of H-ZSM-5 zeolite for C4 olefin catalytic cracking. A series of H-ZSM-5 zeolites with similar sheet-like morphology but different c-axis lengths were synthesized. We found that the catalytic activity and stability is improved in samples with longer c-axis. Combining time-resolved in-situ FT-IR spectroscopy with molecular dynamics simulations, we show that the difference in catalytic performance can be attributed to the anisotropy of the intracrystalline diffusive propensity of the olefins in different channels. Our descriptor offers mechanistic insight for the design of highly effective zeolite catalysts for olefin cracking.

The Effect of Ni Precursor Salts on Diatomite Supported Ni-Mg Catalysts in Methanation of CO2

2021 ◽  
Vol 1016 ◽  
pp. 1417-1422
Author(s):  
Chao Sun ◽  
Jugoslav Krstic ◽  
Vojkan Radonjic ◽  
Miroslav Stankovic ◽  
Patrick da Costa
Keyword(s):  
Catalytic Activity ◽  
Atmospheric Pressure ◽  
Textural Properties ◽  
Catalytic Performance ◽  
Nickel Salt ◽  
Nitrate Salt ◽  
Efficient Catalyst ◽  
Mild Conditions ◽  
The Difference ◽  
Supported Ni

This study is aimed to investigate the effect of Ni precursor salts on the properties (textural, phase-structural, reducibility, and basicity), and catalytic performance of diatomite supported Ni-Mg catalyst in methanation of CO2. The NiMg/D-X catalysts derived from various nickel salts (X = S-sulfamate, N-nitrate or A-acetate) were synthesized by the precipitation-deposition (PD) method. The catalysts were characterized by N2-physisorption, XRD, TPR-H2, and TPD-CO2 techniques. The different catalytic activity (conversion) and selectivity, observed in CO2 methanation carried out under relatively mild conditions (atmospheric pressure; temperatures: 250-450 °C) are related and explained by the difference in textural properties, metallic Ni-crystallite size, reducibility, and basicity of studied catalysts. The results showed that catalyst derived from Ni-nitrate salt (NiMg/D-N) is more suitable for the preparation of efficient catalyst for CO2 methanation than its counterparts derived from sulfamate (NiMg/D-S) or acetate (NiMg/D-A) nickel salt. The NiMg/D-N catalyst showed the highest specific surface area and total basicity, and the best catalytic performance with CO2 conversion of 63.3 % and CH4 selectivity of 80.9 % at 450 °C.

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.

Large-scale and facile synthesis of a porous high-entropy alloy CrMnFeCoNi as an efficient catalyst

2020 ◽  
Vol 8 (35) ◽  
pp. 18318-18326 ◽  
Author(s):  
Hailong Peng ◽  
Yangcenzi Xie ◽  
Zicheng Xie ◽  
Yunfeng Wu ◽  
Wenkun Zhu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Large Scale ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
High Entropy Alloy ◽  
Facile Synthesis ◽  
Efficient Catalyst ◽  
High Entropy

Porous high entropy alloy CrMnFeCoNi exhibited remarkable catalytic activity and stability toward p-nitrophenol hydrogenation. The enhanced catalytic performance not only resulted from the high surface area, but also from exposed high-index facets with terraces.

Oxygen Radicals Occlusion/Release Behavior of Nanoporous Aluminosilicate, Ca12Al14-XSiXO33+0.5X (0≦X≦4)

2006 ◽  
Vol 45 ◽  
pp. 2105-2109
Author(s):  
Makoto Nagashima ◽  
Daisuke Hirabayashi ◽  
Kenzi Suzuki
Keyword(s):  
Catalytic Activity ◽  
Oxygen Content ◽  
Oxygen Radicals ◽  
Catalytic Performance ◽  
Oxygen Release ◽  
Release Behavior ◽  
Temperature Programmed Reduction ◽  
Temperature Programmed Oxidation ◽  
Temperature Range ◽  
Temperature Programmed

Oxygen radicals occlusion / release behavior of nanoporous aluminosilicate, Ca12Al14-XSiXO33+0.5X (0≦X≦4), synthesized under different condition was examined by the temperature programmed reduction (TPR) in an atmosphere of hydrogen in the temperature range of 200-1000°C and temperature programmed oxidation (TPO) measurement at 800°C. From the TPR results of Ca12Al14O33 (X=0) and Ca12Al10Si4O35 (X=4), it was found that there were three oxygen release peaks, denoted as α, β and γ, on each sample and the peaks appeared in the temperature range 300-420°C, 420-600°C, and 600-750°C, respectively. The oxygen contents of α and γ of samples were almost the same. However, the oxygen content of β in the sample with x = 4 was much larger, almost double, compared to that in x = 0. From the TPR, TPO results and catalytic performance, it was concluded that the oxygen content of β peak strongly influenced the catalytic activity of the nanoporous aluminosilicate in the propylene combustion.

Preparation and Characterization of Ni-Modified Fe-Mo and Catalytic Selective Oxidation of p-Xylene

2012 ◽  
Vol 557-559 ◽  
pp. 1501-1504 ◽  
Author(s):  
Zu Zeng Qin ◽  
Zi Li Liu ◽  
Yan Bin Liu ◽  
Rui Wen Liu
Keyword(s):  
Photoelectron Spectrum ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Ni Catalyst ◽  
Temperature Programmed Reduction ◽  
X Ray ◽  
Mo Catalyst ◽  
Ft Ir ◽  
Temperature Programmed

The preparation of the Fe-Mo-Ni catalyst using the sol-gel method was investigated. In addition, the catalytic selective oxidations of p-xylene (PX) to terephthalaldehyde (TPAL) on the Fe-Mo-Ni catalyst were also investigated. The catalysts were characterized using thermal analysis, H2-temperature programmed reduction (H2-TPR), Fourier transform infrared spectra (FT-IR), and X-ray photoelectron spectrum (XPS). The additional of Ni improves the catalytic activity of the Fe-Mo catalyst on selective oxidations of PX to TPAL. The optimal additive amount of Ni is 5%. XPS analysis shows that the introduction of Ni changes the internal structure of the Fe-Mo catalyst improves catalytic performance.

scholarly journals Synergistic Effects of Co3O4-CeO2 Nanoparticles towards Catalytic Oxidation of Aromatic Hydrocarbons: A Study in Association with Carbon Monoxide and Humidity

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Trung Dang-Bao ◽  
Hong Phuong Phan ◽  
Phung Anh Nguyen ◽  
Pham Phuong Trang Vo ◽  
Van Tien Huynh ◽  
...  
Keyword(s):  
Carbon Monoxide ◽  
Catalytic Activity ◽  
Catalytic Oxidation ◽  
Synergistic Effects ◽  
Active Oxygen Species ◽  
High Dispersion ◽  
High Catalytic Activity ◽  
Impregnation Method ◽  
Temperature Programmed ◽  
The Stability

In this study, a series of Co3O4-CeO2 nanocomposites with various Co3O4 loading were fabricated by the impregnation method using cobalt(II) acetate as the cobalt precursor for the treatment of benzene, toluene, ethylbenzene, and xylene (BTEX). The as-prepared Co3O4-CeO2 nanocomposites were thoroughly characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Brumauer-Emmett-Teller (BET), hydrogen temperature-programmed reduction (H2-TPR), and temperature-programmed desorption (O2-TPD). The excellent reproduction of active oxygen species caused by the high dispersion of Co3O4 crystals on the CeO2 supports was established. In addition, the reduction peaks of Co3O4-CeO2 nanocomposites were found at much lower temperatures compared to pure CeO2, considering their unique redox property influencing on the high catalytic activity. Among the characterized materials, the 5.0 wt.% Co3O4 supported on CeO2 (5.0Co–Ce) was the best system for catalytic oxidation of xylene, along with excellent performances in the cases of benzene, ethylbenzene, and toluene. Its catalytic activity increased in the order: benzene < xylene < ethylbenzene < toluene . Furthermore, the addition of carbon monoxide (CO) as a coreactant permitted to improve the catalytic performances in such oxidations as well as the stability of as-prepared catalysts, even under humid conditions.

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.

One-Step FSP Synthesis of Nanocrystalline Fe/Al2O3 and Fe-Ce/Al2O3 Catalyst for CO2 Hydrogenation Reaction

2018 ◽  
Vol 916 ◽  
pp. 134-138 ◽  
Author(s):  
Kanyarat Piriyasurawong ◽  
Sunthon Piticharoenphun ◽  
Okorn Mekasuwandumrong
Keyword(s):  
Catalytic Activity ◽  
Iron Oxide ◽  
Catalytic Performance ◽  
Hydrogenation Reaction ◽  
Flame Spray ◽  
One Step ◽  
Temperature Programmed ◽  
The One ◽  
Long Chain ◽  
Chain Hydrocarbon

Nanocrystalline Fe/Al2O3and Fe-Ce/Al2O3catalysts doped with various amounts of cerium were prepared using the one-step flame spray pyrolysis (FSP) technique. The characterization of the catalysts was measured by several methods such as X-ray diffraction, nitrogen physisorption and hydrogen temperature programmed reduction (H2-TPR) techniques. The results revealed that the FSP-made catalyst exhibited the characteristic pattern of FeAl2O4phase without any phases of aluminum or iron oxide. In addition, cerium (Ce) dopant did not alter crystal structure at low content. However, 7 wt% content of cerium dopant resulted in the formation of ceria (CeO) and iron oxide (Fe2O3) phase. The catalytic performance of the FSP-made catalyst was tested in carbon dioxide hydrogenation for selective production of long chain hydrocarbon, and was compared to conventional impregnation-made catalysts. In the comparison, the FSP-made catalyst exhibited lower catalytic activity but possessed a higher long chain hydrocarbon selectivity. After doping with Ce, the catalytic activity was improved while the hydrocarbon selectivity was decreased and shifted to the short chain hydrocarbon product. In the case of conventional-made catalysts, the activity remained unchanged but the hydrocarbon selectivity was decreased. Among all catalysts, the FSP-made Fe-Ce/Al2O3catalyst with 3% Ce-promoted catalyst exhibited the best performance in terms of selectivity to long chain hydrocarbon.

Electro-Catalytic Performance of Different Pt/Ag Ratio on H2O2 Electro-Reduction for Direct NaBH4-H2O2 Fuel Cell

2014 ◽  
Vol 986-987 ◽  
pp. 59-62
Author(s):  
Ting Fang Yang ◽  
Dan Zheng ◽  
Zao Xi Yu
Keyword(s):  
Cyclic Voltammetry ◽  
Catalytic Activity ◽  
Reduction Method ◽  
Catalytic Performance ◽  
Performance Tests ◽  
Peak Current Density ◽  
Acid Media ◽  
Electro Catalytic Activity ◽  
Xrd And Tem ◽  
Better Than

In this paper the different proportional Pt/Ag on XC-72 carbon are studied to serve as the electro-catalysts of H2O2in acid media. All catalysts are prepared by impregnation reduction method and characterized by XRD and TEM. The electrochemical performance tests are examined by cyclic voltammetry (CV) at 25°C and 30°C, respectively. The results suggest that the peak current density increases with increasing the Ag content in Pt-Ag/C. Attributed to the temperature factor, the electro-catalytic activity of all catalysts at 30°C is better than that of 25°C.

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