Factors affecting the catalytic performance of nano‐catalysts

2021 ◽  
Author(s):  
Hongling Yang ◽  
Yue Wu ◽  
Zewen Zhuang ◽  
Yang Li ◽  
Chen Chen
Keyword(s):  
Catalytic Performance ◽  
Factors Affecting ◽  
Nano Catalysts

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.

scholarly journals Oxidation of soot over supported RuRe nanoparticles prepared by the microwave-polyol method

2021 ◽  
Author(s):  
Katarzyna Adamska ◽  
Szymon Smykała ◽  
Sebastian Zieliński ◽  
Damian Szymański ◽  
Agnieszka Hojeńska ◽  
...  
Keyword(s):  
Bimetallic Nanoparticles ◽  
Catalytic Properties ◽  
Soot Oxidation ◽  
Catalytic Performance ◽  
Polyol Method ◽  
Nano Catalyst ◽  
The Stability ◽  
Nano Catalysts ◽  
The Relationship ◽  
Very High

AbstractThe oxidation of soot over RuRe bimetallic nanoparticles (NPs) supported on γ-Al2O3 has been investigated. The catalysts were synthesized by a microwave-polyol method and characterized by ICP, BET, TEM, STEM-EDS, XRD and XPS techniques. The study revealed that the proper choice of the Re loading (0.4–2.0 wt%) is crucial for the catalytic behavior of the 2% Ru–Re/Al2O3 nano-catalysts.The best catalytic properties, in terms of overall activity and stability, were observed for the 2%Ru-0.8%Re/γ-Al2O3 nano-catalyst. The stability of all bimetallic 2% Ru–Re nano-catalysts in catalytic soot oxidation in the presence of oxygen is very high in contrast to the 2% Ru/γ-Al2O3 sample. The presence of rhenium in the catalytic system hinder the formation of large RuO2 agglomerates leading to a better dispersion of active ruthenium phase and a better catalytic performance. The relationship between the catalytic activity of Ru–Re/γ-Al2O3 and the synergetic roles of Ru and Re is discussed.

Magnesium oxide as a heterogeneous catalyst support

2016 ◽  
Vol 36 (1) ◽  
pp. 1-41 ◽  
Author(s):  
Nurhidayatullaili Muhd Julkapli ◽  
Samira Bagheri
Keyword(s):  
Surface Area ◽  
Heterogeneous Catalyst ◽  
High Surface ◽  
Catalyst Support ◽  
High Surface Area ◽  
Nanocrystalline Structure ◽  
Catalytic Performance ◽  
Acid Base ◽  
Factors Affecting ◽  
Crystal And Electronic Structure

AbstractResearchers normally consider MgO as a promising high-surface-area heterogeneous catalyst support, additive, and promoter for many kinds of chemical reactions due to its certain properties, including stoichiometry and composition, cation valence, redox properties, acid-base character, and crystal and electronic structure. The presence of MgO as a support catalyst also modifies the electronic state of the overall catalytic performance by electron transfer between the native catalyst and MgO as support. The influence is clarified by alteration of acid-base properties of the catalyst-supported MgO. Meanwhile, the method, chemical composition, and condition in the preparation of MgO are the important factors affecting its surface and catalytic properties. Therefore, MgO with a high surface area and nanocrystalline structure has encouraging applications for some reactions, including as dry reforming, dehydrohalogenation, oxidative dehydrogenation of butane, nonoxidative dehydrogenation of ethylbenzene, decomposition of CCl

scholarly journals Preparation of a Modified PTFE Fibrous Photo-Fenton Catalyst and Its Optimization towards the Degradation of Organic Dye

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Zhizhong Ding ◽  
Yongchun Dong ◽  
Bing Li
Keyword(s):  
Metal Ions ◽  
Metal Ion ◽  
Metal Content ◽  
Dye Degradation ◽  
Fiber Surface ◽  
Transition Metal Ions ◽  
Rare Metal ◽  
Catalytic Performance ◽  
Factors Affecting ◽  
Grafting Degree

Polytetrafluoroethylene (PTFE) fiber was grafted with acrylic acid to impart the carboxyl groups onto the fiber surface, which were used to coordinate with both transition metal ions Fe(III) and Cu(II) and a rare metal ion Ce(III) to prepare the metal grafted PTFE fiber complexes as the novel heterogeneous Fenton catalysts for the degradation of the azo dye in water under visible irradiation. Some factors affecting the preparation process, such as nature and concentration of metal ions in the coordination solution, grafting degree of PTFE and reaction temperature were optimized with respect to the content and strength of metal fixation on the fiber and dye degradation efficiency. The results indicated that increasing metal ion concentrations in solution and grafting degree of PTFE fiber as well as higher coordination temperature led to a significant increase in metal content, especially Fe(III) and Cu(II) content of the complexes. Fe(III) ions fixed on the fiber showed the better catalytic performance than Cu(II) and Ce(III) ions fixed when three different complexes with similar metal content being employed, respectively. Moreover, Increasing Fe content or incorporation of Cu(II) ions could significantly improve the catalytic activity of the complexes.

Preparation and Electro-Catalytic Performance of Pt-Ag/C as Electro-Reduction Catalysts for H2O2

2012 ◽  
Vol 608-609 ◽  
pp. 870-874
Author(s):  
Zhang Fei Guo ◽  
Dan Zheng
Keyword(s):  
Cyclic Voltammetry ◽  
Reduction Method ◽  
Chemical Reduction ◽  
Catalytic Performance ◽  
Chemical Reduction Method ◽  
Time Curve ◽  
Current Time ◽  
Catalytic Stability ◽  
Nano Catalysts ◽  
Reduction Catalysts

Using impregnation-chemical reduction method, we prepared Pt/C and Pt-Ag/C nano-catalysts. Both of them are with the same platinum content. The composition of the two catalysts was analyzed by XRD technique. The electrochemical performance was studied by cyclic voltammetry and current-time curve. The results show that: the existence of Ag in the Pt-Ag/C catalyst makes Pt crystallinity decreased; compared with Pt/C, Pt-Ag/C has a higher reductive peak current. In addition, both catalysts show the excellent catalytic stability.

Synthesis of Dimethyl Carbonate from Ethylene Carbonate and Methanol Over Nano-Catalysts Supported on CeO2–MgO

2015 ◽  
Vol 15 (10) ◽  
pp. 8330-8335 ◽  
Author(s):  
Jin Oh Jun ◽  
Joongwon Lee ◽  
Ki Hyuk Kang ◽  
In Kyu Song
Keyword(s):  
Dimethyl Carbonate ◽  
Ethylene Carbonate ◽  
Earth Metal ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Reaction Yield ◽  
Incipient Wetness Impregnation ◽  
Impregnation Method ◽  
Nano Catalyst ◽  
Nano Catalysts

A series of CeO2(X)–MgO(1−X) (X = 0, 0.25, 0.5, 0.75, and 1.0) nano-catalysts were prepared by a co-precipitation method for use in the synthesis of dimethyl carbonate from ethylene carbonate and methanol. Among the CeO2(X)–MgO(1−X) catalysts, CeO2(0.25)–MgO(0.75) nano-catalyst showed the best catalytic performance. Alkali and alkaline earth metal oxides (MO = Li2O, K2O, Cs2O, SrO, and BaO) were then supported on CeO2(0.25)–MgO(0.75) by an incipient wetness impregnation method with an aim of improving the catalytic performance of CeO2(0.25)–MgO(0.75). Basicity of the catalysts was determined by CO2-TPD experiments in order to elucidate the effect of basicity on the catalytic performance. The correlation between catalytic performance and basicity showed that basicity played an important role in the reaction. Yield for dimethyl carbonate increased with increasing basicity of the catalysts. Among the catalysts tested, Li2O/CeO2(0.25)–MgO(0.75) nano-catalyst with the largest basicity showed the best catalytic performance in the synthesis of dimethyl carbonate.

Preparation and catalytic performance of quaternary ammonium base resin for methanolysis of natural phosphatidylcholine

2016 ◽  
Vol 70 (6) ◽  
Author(s):  
Hong-Ya Li ◽  
Xiao-Li Zhang ◽  
Biao Yan ◽  
Bin-Xia Zhao ◽  
Jing Gao
Keyword(s):  
Quaternary Ammonium ◽  
Carbon Chain ◽  
Catalytic Performance ◽  
Exchange Capacity ◽  
Polystyrene Microspheres ◽  
Quaternary Ammonium Base ◽  
Factors Affecting ◽  
Base Resin ◽  
Acceptable Method ◽  
Homogeneous Catalytic Process

AbstractReceived 1 August 2015; Revised 23 November 2015; Accepted 26 November 2015The most acceptable method for preparing glycerophosphocholine is to hydrolyse the natural phosphatidylcholine and use the quaternary ammonium base resin, as a promising heterogeneous catalyst can simplify the craft and minimise the problems existing in the homogeneous catalytic process. However, most of the resins reported in the literature are commercial trimethyl benzyl ammonium base resins and the application of other longer carbon-chain quaternary ammonium resins has not been reported. In the present work, a series of quaternary ammonium base resins were prepared from chloromethyl polystyrene microspheres and different tertiary amines and were used to prepare glycerophosphocholine from natural phosphatidylcholine. The factors affecting the exchange capacity and activity of the resin were investigated. The results showed that the resin possessed a better activity and stability under the following conditions: 1,4-dioxane as solvent, triethylamine as amination agent, reaction temperature of 60°C and amination time of 3 h; it was then used in the methanolysis of phosphatidylcholine by ultrasound-assisted reaction at ambient temperature, with the conversion of phosphatidylcholine attaining 97 % after 4 h. The catalyst was easy to separate from the reaction mixture and could also be readily available for repeat use; the activity and stability were largely consistent after six repeat uses.

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