Catalytic Performance of SO2 by Colloidal Gold Supported on Nano γ-Fe2O3

2010 ◽  
Vol 178 ◽  
pp. 65-70 ◽  
Author(s):  
Sheng Rui Xu ◽  
Qin Shuai ◽  
Jin Hua Cheng ◽  
Xiao Ge Wang
Keyword(s):  
Gas Chromatography ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Metal Oxides ◽  
Water Vapour ◽  
Colloidal Gold ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Sulfate Species

A new catalyst of gold supported on nanometal oxide for oxidation of SO2 was developed. Deposition-precipitation method was used to prepare gold-based catalysts. The catalytic activity of the catalysts was evaluated by determining the concentration of SO2 with gas chromatography under reaction temperature from 100 to 700°C. The results showed that there was an enhancement of catalytic activity when gold nanoparticles were dispersed on the surface of nano-metal oxides, furthermore, γ-Fe2O3 showed the highest activity as the support of the colloidal gold supported catalysts among the nanometal oxides including γ-Fe2O3, Fe2O3, ZnO, and Al2O3. It was also found that water vapour in the reaction enhanced the catalytic activity of Au/γ-Fe2O3. The Au/γ-Fe2O3 was characterized by XRD and FTIR methods, which indicated that the gold nanoparticles were dispersed on the γ-Fe2O3 support and sulfate species were formed on the surface of catalysts.

scholarly journals Effect of the oxygen coordination environment of Ca–Mn oxides on the catalytic performance of Pd supported catalysts for aerobic oxidation of 5-hydroxymethyl-2-furfural

2019 ◽  
Vol 9 (23) ◽  
pp. 6659-6668 ◽  
Author(s):  
Jie Yang ◽  
Haochen Yu ◽  
Yanbing Wang ◽  
Fuyuan Qi ◽  
Haodong Liu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Charge Transfer ◽  
Active Sites ◽  
Supported Catalysts ◽  
Aerobic Oxidation ◽  
Oxygen Adsorption ◽  
Catalytic Performance ◽  
Coordination Environment ◽  
Oxygen Coordination ◽  
Mn Oxides

Pd/CaMn2O4 provides ideal active sites for oxygen adsorption and desorption, resulting in the promoted charge transfer ability and catalytic activity.

scholarly journals Preparation of Metal Oxides Containing ppm Levels of Pd as Catalysts for the Reduction of Nitroarene and Evaluation of Their Catalytic Activity by the Fluorescence-Based High-Throughput Screening Method

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 542
Author(s):  
Taeho Lim ◽  
Min Su Han
Keyword(s):  
Catalytic Activity ◽  
Metal Oxides ◽  
High Throughput ◽  
High Throughput Screening ◽  
Screening Method ◽  
Reduction Reaction ◽  
Precipitation Method ◽  
Reaction Conditions ◽  
One Pot ◽  
Co Precipitation

Herein, an easily accessible and efficient green method for the reduction of nitroarene compounds was developed using metal oxide catalysts. Heterogeneous metal oxides with or without Pd were prepared by a simple and scalable co-precipitation method and used for the reduction of nitroarenes. A fluorescence-based high-throughput screening (HTS) method was also developed for the rapid analysis of the reaction conditions. The catalytic activity of the metal oxides and reaction conditions were rapidly screened by the fluorescence-based HTS method, and Pd/CuO showed the highest catalytic activity under mild reaction conditions. After identifying the optimal reaction conditions, various nitroarenes were reduced to the corresponding aniline derivatives by Pd/CuO (0.005 mol% of Pd) under these conditions. Furthermore, the Pd/CuO catalyst was used for the one-pot Suzuki–Miyaura cross-coupling/reduction reaction. A gram-scale reaction (20 mmol) was successfully performed using the present method, and Pd/CuO showed high reusability without a loss of catalytic activity for five cycles.

Magnetic Spinel Ferrite: An Efficient, Reusable Nano Catalyst for HMFSynthesis

2021 ◽  
Vol 10 ◽  
Author(s):  
Jyoti Dhariwal ◽  
Ravina Yadav ◽  
Sheetal Yadav ◽  
Anshu Kumar Sinha ◽  
Chandra Mohan Srivastava ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Surface Area ◽  
Heterogeneous Catalysts ◽  
Spinel Ferrite ◽  
Active Surface ◽  
Catalytic Performance ◽  
Ferrite Nanoparticles ◽  
Precipitation Method ◽  
Magnetic Characteristics ◽  
Nano Catalyst

Aim: In the present work, the preparation and catalytic activity of spinel ferrite [MFe2O4; M = Fe, Mn, Co, Cu, Ni] nanoparticles to synthesize 5-hydroxymethylfurfural (HMF) have been discussed. Background: Ferrites possess unique physicochemical properties, including excellent magnetic characteristics, high specific surface area, active surface sites, high chemical stability, tunable shape and size, and easy functionalization. These properties make them essential heterogeneous catalysts in many organic reactions. Objective: This study aims to synthesize a series of transition metal ferrite nanoparticles and use them in the dehydration of carbohydrates for 5-hydroxymethylfurfural (HMF) synthesis. Method: The ferrite nanoparticles were prepared via the co-precipitation method, and PXRD confirmed their phase stability. The surface area and the crystallite size of the nanoparticles were calculated using BET and PXRD, respectively. Result: The easily prepared heterogeneous nanocatalyst showed a significant catalytic performance, and among all spinel ferrites, CuFe2O4 revealed maximum catalytic ability. Conclusion: Being a heterogeneous catalyst and magnetic in nature, ferrite nanoparticles were easily recovered by using an external magnet and reused up to several runs without substantial loss in catalytic activity. Others: HMF was synthesized from fructose in a good yield of 71%.

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.

Effect of Different Silicate Supports on the Catalytic Performance of MoVTeO Mixed Oxides in Partial Oxidation of Isobutane

2014 ◽  
Vol 12 (1) ◽  
pp. 623-628
Author(s):  
Jing Hu ◽  
Zhifang Li ◽  
Xiaoyuan Yang ◽  
Wenli Ding ◽  
Jingqi Guan
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Partial Oxidation ◽  
Mixed Oxides ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Surface Areas ◽  
Specific Surface Areas ◽  
Mcm 41

Abstract A series of 5% MoV0.3Te0.25 supported on different silicates (i.e. SiO2, HMS, MCM-41, and MCM-48) have been prepared, characterized, and tested as catalysts in the partial oxidation of isobutane to methacrolein. Characterization results showed that the supports almost kept intact structures after supporting 5 wt.% MoV0.3Te0.25 and the supported catalysts had large specific surface areas. Catalytic tests showed that the specific surface area played a key role in the catalytic activity for the supported catalysts.

scholarly journals Size controlled green synthesis of gold nanoparticles using Coffea arabica seed extract and their catalytic performance in 4-nitrophenol reduction

RSC Advances ◽  
2018 ◽  
Vol 8 (44) ◽  
pp. 24819-24826 ◽  
Author(s):  
N. K. R. Bogireddy ◽  
U. Pal ◽  
L. Martinez Gomez ◽  
V. Agarwal
Keyword(s):  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Green Synthesis ◽  
Coffea Arabica ◽  
Room Temperature ◽  
Catalytic Performance ◽  
Seed Extract ◽  
Size Dependent ◽  
Nitrophenol Reduction ◽  
Size Controlled

Size dependent catalytic activity of AuNPs synthesized at room temperature from Coffea arabica seed extract.

The Effects of Different Preparation Conditions of IR Catalyst on the Simultaneous Removal of Soot and NOx in the Presence of Rich Oxygen and H2O as Well as SO2

2012 ◽  
Vol 428 ◽  
pp. 61-64 ◽  
Author(s):  
Ting Kun Gu ◽  
Rong Shu Zhu ◽  
Feng Ouyang
Keyword(s):  
Catalytic Activity ◽  
Calcination Temperature ◽  
Supported Catalysts ◽  
Catalytic Performance ◽  
Simultaneous Removal ◽  
Impregnation Method ◽  
Support Material ◽  
Calcination Time ◽  
Preparation Conditions ◽  
Calcination Atmosphere

A series of Ir-supported catalysts were prepared by incipient impregnation method. The activity of Ir catalyst for the simultaneous removal of soot and NOx in the presence of rich-oxygen and H2O as well as SO2 has been studied, and the effects of calcination temperature, calcination time, calcination atmosphere, loading, carrier and precursor on its catalytic performance has also been investigated. Ir catalyst exhibits a high activity. With the calcination temperature increasing, Ir catalytic activity increases firstly and then decreases, and the optimal calcination temperature is 900°C. With the calcination time prolonged, Ir catalytic activity also increases firstly and then decreases, and the optimal calcination time is 3h. The optimal calcination atmosphere is 1.5vol.% H2/N2. Support material and precursor have a little effect on the catalytic activity, and the order is Ir/TiO2 > Ir/ZrO2 > Ir/SiO2 > Ir/Al2O3 > Ir/ZSM-5 and IrCl (CO)[P(C6H5)3]2/ZrO2 > H2IrCl6·6H2O/ZrO2 > IrCl4·4H2O/ZrO2.

scholarly journals Preparation of AuNPs/GQDs/SiO2 Composite and Its Catalytic Performance in Oxidation of Veratryl Alcohol

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Yaoyao Yang ◽  
Jiali Zhang ◽  
Fangwei Zhang ◽  
Shouwu Guo
Keyword(s):  
Quantum Dots ◽  
Gold Nanoparticles ◽  
Catalytic Activity ◽  
Silicon Dioxide ◽  
Graphene Quantum Dots ◽  
Veratryl Alcohol ◽  
Catalytic Performance ◽  
Amide Bond ◽  
Amino Group ◽  
Reaction Systems

Composites of gold nanoparticles and graphene quantum dots (AuNPs/GQDs) exhibit excellent dispersibility in aqueous solutions. Thus, it is difficult to separate them from wet reaction systems when they are used as catalysts. To resolve this issue, in this study, an AuNPs/GQDs composite was immobilized on silicon dioxide through the hydrothermal method, which involved the formation of an amide bond between the surface GQDs of the AuNPs/GQDs composite and the amino group of the silane. The as-synthesized AuNPs/GQDs/SiO2 composite was found to be suitable for use as a heterogeneous catalyst for the oxidation of veratryl alcohol in water and exhibited catalytic activity comparable to that of bare AuNPs/GQDs as well as better recyclability.

scholarly journals Gold Nanoparticles Supported on Urchin-Like CuO: Synthesis, Characterization, and Their Catalytic Performance for CO Oxidation

Nanomaterials ◽  
2019 ◽  
Vol 10 (1) ◽  
pp. 67 ◽  
Author(s):  
Feng Dong ◽  
Yuan Guo ◽  
Dongyang Zhang ◽  
Baolin Zhu ◽  
Weiping Huang ◽  
...  
Keyword(s):  
Gold Nanoparticles ◽  
Co Oxidation ◽  
Solution Method ◽  
Catalytic Mechanism ◽  
Gold Catalysts ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Metallic State ◽  
Reaction Cycles ◽  
Cuo Microspheres

Gold catalysts have been studied in-depth due to their unique activities for catalytic CO oxidation. Supports have intrinsic motivation for the high activity of gold catalysts. Thermally stable urchin-like CuO microspheres, which are potential support for gold catalysts, were prepared by facile solution-method. Then gold nanoparticles were loaded on them by deposition-precipitation method. The obtained gold catalysts were characterized by SEM, XRD, TEM, BET, ICP, and XPS. Their catalytic activity for CO oxidation was also evaluated. TEM results revealed that the gold nanoparticles with small sizes were highly distributed on the CuO surface in Au1.0/CuO-300. XPS observations demonstrated that the gold species in Au1.0/CuO-300 was of metallic state. Among the as-prepared catalysts, the Au1.0/CuO-300 catalyst displayed the best performance for CO oxidation and achieved 100% CO oxidation at 80 °C. It kept 100% conversion for 20 h at a reaction temperature of 180 °C, and showed good reusability after three reaction-cycles. The possible catalytic mechanism of Au1.0/CuO-300 catalyst for CO oxidation was also briefly proposed.

Effect of Silica Promoter on Performance of CuO-ZnO-ZrO2 Catalyst for Methanol Synthesis from CO2 Hydrogenation

2014 ◽  
Vol 556-562 ◽  
pp. 117-122 ◽  
Author(s):  
Miao Yao Jia ◽  
Wen Gui Gao ◽  
Hua Wang ◽  
Yu Hao Wang
Keyword(s):  
Catalytic Activity ◽  
Specific Surface ◽  
Surface Area ◽  
Methanol Synthesis ◽  
Catalytic Properties ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Test Results ◽  
Excellent Performance ◽  
Co Precipitation

Various CuO-ZnO-ZrO2(CZZ) catalysts for methanol synthesis from CO2 hydrogenation were prepared by co-precipitation method. Small amount of silica was incorporated into CZZ catalyst to produce these modified ternary CZZ catalysts. The effects of silica on physicochemical and catalytic properties were studied by TG-DTG,XRD,BET,N2O chemisorption,H2-TPR,NH3-TPD and CO2-TPD techniques. The results show that the properties of catalysts were strongly influenced by the content of SiO2 used as promoter. The catalytic performance for methanol synthesis from CO2 hydrogenation was evaluated. The test results show that the CZZ catalyst modified with 4 wt.% SiO2 exhibits an optimum catalytic activity. The silica improves the dispersion of CuO and its modified CZZ catalysts exhibits higher specific surface area, which were confirmed to be responsible for excellent performance of the catalysts for methanol synthesis from CO2 hydrogenation.

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