The properties and catalytic performance of PtIn/Mg(Al)O catalysts for the propane dehydrogenation reaction: Effects of pH value in preparing Mg(Al)O supports by the co-precipitation method

2016 ◽  
Vol 338 ◽  
pp. 104-114 ◽  
Author(s):  
Ke Xia ◽  
Wan-Zhong Lang ◽  
Pei-Pei Li ◽  
Xi Yan ◽  
Ya-Jun Guo
Keyword(s):  
Ph Value ◽  
Catalytic Performance ◽  
Propane Dehydrogenation ◽  
Precipitation Method ◽  
Dehydrogenation Reaction ◽  
Effects Of Ph ◽  
Co Precipitation

Preparation and Characterization of Bismuth Molybdate Catalyst for Oxidative Dehydrogenation of n-Butene into 1,3-Butadiene

2007 ◽  
Vol 119 ◽  
pp. 251-254 ◽  
Author(s):  
Ji Chul Jung ◽  
Hee Soo Kim ◽  
Ahn Seop Choi ◽  
Young Min Chung ◽  
Tae Jin Kim ◽  
...  
Keyword(s):  
Oxidative Dehydrogenation ◽  
Ph Value ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Precipitation Method ◽  
Mixed Catalyst ◽  
High Diffusion Coefficient ◽  
Co Precipitation

α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts were prepared by co-precipitation method, and they were applied to the oxidative dehydrogenation of n-butene into 1,3-butadiene in a continuous flow fixed-bed reactor. Formation of α-Bi2Mo3O12 and γ-Bi2MoO6 catalysts was well confirmed by XRD, Raman spectroscopy, and ICP-AES analyses. The γ-Bi2MoO6 catalyst exhibited a better catalytic performance than the α-Bi2Mo3O12 catalyst. Catalytic performance of γ-Bi2MoO6 strongly depended on the pH value used in the co-precipitation step. It was also revealed that a mixed catalyst comprising γ-Bi2MoO6 (90 wt%) and small amount of α-Bi2Mo3O12 (10 wt%) showed the best catalytic performance due to the synergy effect of two components. It is believed that the high catalytic performance of the mixed catalyst resulted from high diffusion coefficient of lattice oxygen in the γ-Bi2MoO6 and from abundant chemisorption sites for n-butene in the α-Bi2Mo3O12.

Effect of Fe and Co promoters on CO methanation activity of nickel catalyst prepared by impregnation – co-precipitation method

2020 ◽  
Vol 18 (5-6) ◽  
Author(s):  
Buyan-Ulzii Battulga ◽  
Tungalagtamir Bold ◽  
Enkhsaruul Byambajav
Keyword(s):  
Synergetic Effect ◽  
Space Velocity ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Alumina Support ◽  
Co Methanation ◽  
Temperature Range ◽  
Co Precipitation ◽  
Catalyst Distribution

AbstractNi based catalysts supported on γ-Al2O3 that was unpromoted (Ni/γAl2O3) or promoted (Ni–Fe/γAl2O3, Ni–Co/γAl2O3, and Ni–Fe–Co/γAl2O3) were prepared using by the impregnation – co-precipitation method. Their catalytic performances for CO methanation were studied at 3 atm with a weight hourly space velocity (WHSV) of 3000 ml/g/h of syngas with a molar ratio of H2/CO = 3 and in the temperature range between 130 and 350 °C. All promoters could improve nickel distribution, and decreased its particle sizes. It was found that the Ni–Co/γAl2O3 catalyst showed the highest catalytic performance for CO methanation in a low temperature range (<250 °C). The temperatures for the 20% CO conversion over Ni–Co/γAl2O3, Ni–Fe/γAl2O3, Ni–Fe–Co/γAl2O3 and Ni/γAl2O3 catalysts were 205, 253, 263 and 270 °C, respectively. The improved catalyst distribution by the addition of cobalt promoter caused the formation of β type nickel species which had an appropriate interacting strength with alumina support in the Ni–Co/γAl2O3. Though an addition of iron promoter improved catalyst distribution, the methane selectivity was lowered due to acceleration of both CO methanation and WGS reaction with the Ni–Fe/γAl2O3. Moreover, it was found that there was no synergetic effect from the binary Fe–Co promotors in the Ni–Fe–Co/γAl2O3 on catalytic activity for CO methanation.

Catalytic Hydrolysis of Hydrogen Cyanide on Cu-Al Catalyst

2015 ◽  
Vol 1094 ◽  
pp. 15-19
Author(s):  
Lin Xia Yan ◽  
Sen Lin Tian ◽  
Qiu Lin Zhang
Keyword(s):  
Calcination Temperature ◽  
Hydrogen Cyanide ◽  
Influence Factor ◽  
Ph Value ◽  
Precipitation Method ◽  
Molar Ratio ◽  
Cu Content ◽  
Co Precipitation ◽  
The Impact ◽  
Hydrolysis Of

Cu-Al catalysts were synthesized by the co-precipitation method to study hydrolysis of hydrogen cyanide. During the synthesis, the impact of Cu/Al molar ratio, pH value and calcination temperature was investigated and the best synthesis condition was found. The results indicate that the remove of hydrogen cyanide first increases and then decreases with increasing Cu/Al molar ratio, pH value and calcination temperature, which reaches the maxima and remains above 95% at 360 min when Cu/Al molar ratio is 2:1, pH value is approximately 8.0 and calcination temperature is 400°C around. The analysis of X-ray diffraction (XRD) shows that Cu content is the main influence factor at Cu/Al molar ratio below 2:1 whereas crystallinity of catalysts is the key factor at Cu/Al molar ratio above 2:1.

Sonochemical Synthesis of Silica Coated Super Paramagnetic Iron Oxide Nanoparticles

2013 ◽  
Vol 756 ◽  
pp. 74-79 ◽  
Author(s):  
Bashiru Kayode Sodipo ◽  
Azlan Abdul Aziz
Keyword(s):  
Iron Oxide ◽  
Silica Nanoparticles ◽  
Iron Oxide Nanoparticles ◽  
Ph Value ◽  
Superparamagnetic Iron Oxide ◽  
Silica Nanoparticle ◽  
Precipitation Method ◽  
Oxide Nanoparticles ◽  
Sonochemical Method ◽  
Co Precipitation

Superparamagnetic iron oxide nanoparticles (SPION) of sizes 5 to10 nm were synthesized by the co-precipitation method. They are coated with silica nanoparticles using sonication method. The SPION was produced under the optimum pH of 10, peptized in acidic medium and redispersed in water. The silica nanoparticles were produced through the Stöbermethod. Sonochemical coating of silica nanoparticle on the SPION was successfulat a pH value lower than 5. Otherwise, at higher pH value (but lower than point zero charge (PZC)), the SPION were found to be unstable. Fast hydrolysis of triethoxyvinylsilane(TEVS) shows that silica forms its own particles without coating onto the surfaces of the SPION. Under optimized experimental condition, sonochemical method of coating silica nanoparticles onto the SPION can be considered as an alternative for effective and prompt method that rely mainly on pH of the suspension.

scholarly journals Effect of Y Modified Ceria Support in Mono and Bimetallic Pd–Au Catalysts for Complete Benzene Oxidation

Catalysts ◽  
2018 ◽  
Vol 8 (7) ◽  
pp. 283 ◽  
Author(s):  
Lyuba Ilieva ◽  
Anna Venezia ◽  
Petya Petrova ◽  
Giuseppe Pantaleo ◽  
Leonarda Liotta ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Benzene Oxidation ◽  
Total Oxidation ◽  
Pd Catalysts ◽  
X Ray ◽  
Close Relationship ◽  
Ceria Support ◽  
Co Precipitation

Mono metallic and bimetallic Pd (1 wt. %)–Au (3 wt. %) catalysts were prepared using two ceria supports doped with 1 wt. % Y2O3. Yttrium was added by impregnation or co-precipitation. The catalyst synthesis was carried out by deposition–precipitation method, with sequential deposition–precipitation of palladium over previously loaded gold in the case of the bimetallic samples. The obtained materials, characterized by X-ray powder diffraction (XRD), High resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS), and temperature programmed reduction (TPR) techniques, were tested in the complete benzene oxidation (CBO). The results of the characterization analyses and the catalytic performance pointed to a close relationship between structural, redox, and catalytic properties of mono and bimetallic catalysts. Among the monometallic systems, Pd catalysts were more active as compared to the corresponding Au catalysts. The bimetallic systems exhibited the best combustion activity. In particular, over Pd–Au supported on Y-impregnated ceria, 100% of benzene conversion towards total oxidation at the temperature of 150 °C was obtained. Comparison of surface sensitive XPS results of fresh and spent catalysts ascertained the redox character of the reaction.

scholarly journals Synthesis of DME by CO2 hydrogenation over La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts

2017 ◽  
Vol 23 (1) ◽  
pp. 49-56 ◽  
Author(s):  
Yajing Zhang ◽  
Yu Zhang ◽  
Fu Ding ◽  
Kangjun Wang ◽  
Wang Xiaolei ◽  
...  
Keyword(s):  
Photoelectron Spectroscopy ◽  
Direct Synthesis ◽  
Catalytic Performance ◽  
Co2 Hydrogenation ◽  
Precipitation Method ◽  
X Ray ◽  
Temperature Programmed ◽  
And Performance ◽  
Co Precipitation ◽  
Adsorption Desorption

A series of La2O3-modified CuO-ZnO-ZrO2/HZSM-5 catalysts were prepared by an oxalate co-precipitation method. The catalysts were fully characterized by X-ray diffraction (XRD), N2 adsorption-desorption, hydrogen temperature pro-grammed reduction (H2-TPR), ammonia temperature programmed desorption (NH3-TPD), and X-ray photoelectron spectroscopy (XPS) techniques. The effect of the La2O3 content on the structure and performance of the catalysts was thoroughly investigated. The catalysts were evaluated for the direct synthesis of dimethyl ether (DME) from CO2 hydrogenation. The results displayed that La2O3 addition enhanced catalytic performance, and the maximal CO2 conversion (34.3%) and DME selectivity (57.3%) were obtained over the catalyst with 1% La2O3, which due to the smaller size of Cu species and a larger ratio of Cu+/Cu.

Enhancing the catalytic performance of cobalt oxide by doping on ceria in the high temperature water–gas shift reaction

RSC Advances ◽  
2015 ◽  
Vol 5 (125) ◽  
pp. 103023-103029 ◽  
Author(s):  
Ajay Jha ◽  
Dae-Woon Jeong ◽  
Yeol-Lim Lee ◽  
In Wook Nah ◽  
Hyun-Seog Roh
Keyword(s):  
High Temperature ◽  
Catalytic Performance ◽  
Water Gas Shift ◽  
Precipitation Method ◽  
High Temperature Water ◽  
Wgs Reaction ◽  
Co Precipitation ◽  
Shift Reaction ◽  
Water Gas ◽  
Temperature Water

The high temperature water–gas shift (HT-WGS) reaction was performed using a Co–CeO2 catalyst, prepared through a co-precipitation method.

Synthesis Conditions of Nano-Hydroxyapatite Using Chondroitin Sulfate by Co-Precipitation Method

2011 ◽  
Vol 236-238 ◽  
pp. 2076-2079
Author(s):  
Yan Rong Sun ◽  
Tao Fan ◽  
Yong Huang ◽  
Li Guo Ma ◽  
Feng Liu
Keyword(s):  
Chondroitin Sulfate ◽  
Ph Value ◽  
Orthogonal Design ◽  
Precipitation Method ◽  
Synthesis Process ◽  
X Ray Diffraction ◽  
Powder Morphology ◽  
Synthesis Conditions ◽  
Transmission Electron ◽  
Co Precipitation

The introduction of biomineralization was coupled with the co-precipitation synthesis process of nano-hydroxyapatite with the addition of chondroitin sulfate as a template agent. The effect of a variety of processing conditions on the properties of final hydroxyapatite (HA) product was investigated by orthogonal design. The ratio of calcium to phosphorus was detected by chemical analysis, the phase composition was evaluated by X-ray diffraction (XRD), and the powder morphology was characterized by transmission electron microscope (TEM). The process scheme, moreover, was optimized by the analysis of four aspects which may have different extent of influence on product properties. It can be concluded from the results that product properties can be affected remarkably by the content of chondroitin sulfate and the pH value of reactant, less remarkably by the reaction temperature and slightly by the reaction time.

Nanoparticles of Cu–Co alloy derived from layered double hydroxides and their catalytic performance for higher alcohol synthesis from syngas

RSC Advances ◽  
2015 ◽  
Vol 5 (72) ◽  
pp. 58804-58812 ◽  
Author(s):  
Ang Cao ◽  
Guilong Liu ◽  
Yizhi Yue ◽  
Lihong Zhang ◽  
Yuan Liu
Keyword(s):  
Layered Double Hydroxides ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Higher Alcohol Synthesis ◽  
Higher Alcohol ◽  
Alcohol Synthesis ◽  
Co Precipitation ◽  
Double Hydroxides

A series of layered double hydroxides (LDHs) with different Cu/Co ratios were prepared according to the co-precipitation method and used as catalyst precursors for higher alcohol synthesis.

STUDY ON NANO COPPER-BASED CATALYSTS FOR THE HYDROGENATION OF METHYL 3-HYDROXYPROPIONATE TO 1, 3-PROPANEDIOL

2009 ◽  
Vol 16 (03) ◽  
pp. 343-349 ◽  
Author(s):  
YUZHOU YING ◽  
KANKA FENG ◽  
ZHIGUO LV ◽  
ZHENMEI GUO ◽  
JINSHENG GAO
Keyword(s):  
Fixed Bed ◽  
Side Reaction ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Precipitation Method ◽  
Active Components ◽  
Analysis Technique ◽  
Co Precipitation ◽  
Nano Catalysts ◽  
Adsorption Desorption

Nano copper-based catalysts were prepared by co-precipitation method and the performance of catalytic hydrogenation for methyl 3-hydroxypropionate (MHP) to 1, 3-propanediol (1, 3-PDO) on the nano catalysts were studied under a high-pressure microcontinuum fixed-bed reactor. The effects of structure, texture, and composition of the catalysts on the catalytic performance were investigated by characterizing the catalysts with XRD, TG–DTG, SEM, and N 2 adsorption/desorption analysis technique. The results showed that addition of promoters enhanced the activity and selectivity of copper-based catalysts, which promoted the dispersion of the active components effectively and stabilized the active center of the catalysts. Especially, the copper-based catalyst of loaded P could restrain side-reaction effectively and improve selectivity obviously, the conversion of MHP and the selectivity of 1, 3-PDO could be 91.30% and reach 90.15%, respectively.

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