scholarly journals Synergy between Ni and Co Nanoparticles Supported on Carbon in Guaiacol Conversion

Nanomaterials ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 2199
Author(s):  
Elodie Blanco ◽  
Ana Belen Dongil ◽  
Néstor Escalona
Keyword(s):  
Liquid Phase ◽  
Bimetallic Catalysts ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
N2 Adsorption ◽  
Nickel Cobalt ◽  
Co Nanoparticles ◽  
Adsorption Desorption

Nickel-cobalt bimetallic catalysts supported on high surface area graphite with different Ni:Co ratios (3:1, 2:1 and 1:1) and the monometallic Ni and Co were prepared by wetness impregnation method. The catalysts were tested in hydrodeoxygenation (HDO) of guaiacol in the liquid phase at 50 bar of H2 and 300 °C. The materials were characterized by N2 adsorption–desorption, XRD, TEM/STEM, H2-TPR, and CO-chemisorption to assess their properties and correlate them with the catalytic results. The activity was higher on the bimetallic catalysts and followed the trend NiCo2:1/G ∼ NiCo3:1/G > NiCo1:1/G > Co/G > Ni/G. Also, selectivity results showed that Ni was more active in the hydrogenation favoring cyclohexanol production from phenol, while this was inhibited on the Co-containing catalysts. Hence, the results showed that synergy was created between Ni and Co and that their interaction, properties, and catalytic performance depend on the metals’ ratio.

scholarly journals Activity Evaluation of CoMo Nanoparticles Supported on Meso-microporous Composites in Dibenzothiophene Hydrodesulphurization

2019 ◽  
Vol 15 (1) ◽  
pp. 112-118
Author(s):  
Nastaran Parsafard ◽  
Mohammad Hasan Peyrovi ◽  
Zahra Mohammadian ◽  
Niloofar Atashi
Keyword(s):  
Activation Energy ◽  
High Surface ◽  
High Surface Area ◽  
Fixed Bed ◽  
Catalytic Performance ◽  
Fixed Bed Reactor ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Ft Ir ◽  
Adsorption Desorption

CoMo-supported mesoporous catalysts were synthesized by 50 wt% of HZSM-5 and 50 wt% of FSM-16, KIT-6, and MCM-48. These catalysts were prepared by the wet-impregnation method and pre-sulfided with CS2. The catalytic performance was evaluated for HDS reaction of dibenzothiophene over a temperature range of 250-400 °C in a micro fixed-bed reactor under atmospheric pressure. The supported CoMo bimetallic catalysts were characterized by XRD, XRF, FT-IR, N2 adsorption-desorption, and SEM. The CoMo/KIT-6/HZSM-5 indicate higher activity than other catalysts at 400 °C for dibenzothiophene hydrodesulphurization. Also, the best selectivity to cyclohexylbenzene (CHB) is related to CoMo/FSM-16/HZSM-5. The activation energy was also calculated for all prepared catalysts for the conversions of less than 10%; according to which, the activation energy for CoMo/KIT-6/HZSM-5 is less than other catalysts (~21 kJ/mol) which can be related to the appropriate pore size and high surface area of the support. Copyright © 2020 BCREC Group. All rights reserved 

Silica-supported Cu–Pt bimetallic catalysts for liquid-phase diethyl oxalate hydrogenation

2018 ◽  
Vol 96 (4) ◽  
pp. 394-403 ◽  
Author(s):  
Wei Long ◽  
Pingle Liu ◽  
Yang Lv ◽  
Wei Xiong ◽  
Fang Hao ◽  
...  
Keyword(s):  
Liquid Phase ◽  
Photoelectron Spectroscopy ◽  
Bimetallic Catalysts ◽  
Nitrogen Adsorption ◽  
Hydrogen Uptake ◽  
Copper Catalysts ◽  
Catalytic Performance ◽  
Diethyl Oxalate ◽  
Hydrogen Chemisorption ◽  
Adsorption Desorption

Silica-supported copper catalysts were prepared by different methods, and Cu/SiO2 prepared by the urea-assisted gel method was modified with co-catalyst platinum to obtain Cu-Pt/SiO2 bimetallic catalysts. The prepared catalysts were characterized by nitrogen adsorption–desorption, XRD, TEM, hydrogen chemisorption, ammonia gas chemisorption, and X-ray photoelectron spectroscopy. The characterization results show that the modification of platinum is helpful to the reduction and dispersion of copper species, which increase the hydrogen uptake quantity and metal surface area. The 30%Cu–3.0%Pt/SiO2-6 presents the best catalytic performance in liquid-phase diethyl oxalate hydrogenation; it gives 77.32% conversion of diethyl oxalate and 94.37% selectivity to the main products under 473 K and 3.0 MPa for 4 h. A possible reaction route was also proposed.

scholarly journals Synthesis and characterization of mesoporous materials with SBA and MCM structure types

Cerâmica ◽  
2019 ◽  
Vol 65 (376) ◽  
pp. 585-591
Author(s):  
R. A. Sacramento ◽  
O. M. S. Cysneiros ◽  
B. J. B. Silva ◽  
A. O. S. Silva
Keyword(s):  
Surface Area ◽  
Mesoporous Materials ◽  
High Surface ◽  
High Surface Area ◽  
Textural Properties ◽  
N2 Adsorption ◽  
Structure Directing Agent ◽  
Type Iv ◽  
Xrd Patterns ◽  
Adsorption Desorption

Abstract Mesoporous materials are promising structures for application in catalysis and adsorption due to high surface area and large pore size. Mesoporous materials were synthesized by the hydrothermal method with novel surfactants, distinct from those observed in the literature, in order to carry out a study of its structure and to obtain materials with better textural properties. The structures synthesized with the surfactants Igepal CO630 and Brij O20 presented the best results of specific surface area, 1074 and 1075 m2.g-1, respectively. The obtained materials were characterized by XRD, TG/DTG, N2 adsorption-desorption, and FTIR techniques. XRD patterns indicated that the highly ordered mesoporous silica structures, such as MCM-41 and MCM-48, using CTMABr as the structure-directing agent and the SBA-15, SBA-16 and other SBA structures using different block copolymers were obtained. Through N2 adsorption-desorption isotherms, it was observed type IV isotherms, attributed to mesoporous materials. The FTIR spectra presented similar behaviors with characteristic vibrational bands of MCM and SBA type materials.

Solvent-Free Liquid Phase Oxidation of Benzyl Alcohol to Benzaldehyde over Superfine MgAl2O4 Supported Co-Based Catalysts：Effects of Support MgAl2O4

2011 ◽  
Vol 233-235 ◽  
pp. 1100-1107
Author(s):  
Xin Zhang ◽  
Mi Qi ◽  
Gui Quan Zhang ◽  
Tao Lin ◽  
Ting Gong
Keyword(s):  
Liquid Phase ◽  
Benzyl Alcohol ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Liquid Phase Oxidation ◽  
Precipitation Method ◽  
Isothermal Adsorption ◽  
Oxidation Of Benzyl Alcohol ◽  
Phase Oxidation

MgAl2O4 was respectively prepared by hydrothermal method (MgAl2O4-HT), co-precipitation method (MgAl2O4-CP) and solid reaction method (MgAl2O4-SR). The as-synthesized MgAl2O4 was used as support to prepare CoOx/MgAl2O4 catalysts for the liquid phase oxidation of benzyl alcohol to benzaldehyde by H2O2. The catalytic performance and properties of these supports and catalysts were comparatively investigated by catalytic test, XRD, XRF, N2 isothermal adsorption-desorption, TEM and H2-TPR technologies. The properties of support MgAl2O4 was strongly depended on the preparation method of the support, which affected the catalytic activity of CoOx/MgAl2O4 catalysts in the reaction. CoOx/MgAl2O4-HT exhibited the higher catalytic reactivity and better reusability than CoOx/MgAl2O4-CP and CoOx/MgAl2O4-SR in the reaction, because MgAl2O4-HT was high-surface-area porous nanometer spinel MgAl2O4.

scholarly journals Synthesis of Mesoporous Zn1−xMxAl2O4 Substituted by Co2+ and Ni2+ Ions and Application in the Photodegradation of Rhodamine B

Materials ◽  
2020 ◽  
Vol 13 (9) ◽  
pp. 2150
Author(s):  
Nilson Machado Pontes do Nascimento ◽  
Bárbara Ronara Machado de Lima ◽  
José Roberto Zamian ◽  
Carlos Emmerson Ferreira da Costa ◽  
Luís Adriano Santos do Nascimento ◽  
...  
Keyword(s):  
Surface Area ◽  
Rhodamine B ◽  
Removal Rate ◽  
Spinel Phase ◽  
High Surface ◽  
High Surface Area ◽  
N2 Adsorption ◽  
Energy Dispersion Spectroscopy ◽  
Nickel Ions ◽  
Adsorption Desorption

A new mesoporous Zn1-xMxAl2O4 photocatalyst was prepared using the metal-chitosan complexation method with different degrees of Zn2+ cation substitution with cobalt and nickel ions (M = Co2+ and Ni2+). Characterization using X-ray diffraction (XRD), Infrared absorption spectrometry (FTIR), energy dispersion spectroscopy (EDS), diffuse reflectance spectrometry (DRS), scanning electron miscoscopy (SEM), transmission electron miscroscopy (TEM), N2 adsorption- desorption isotherms using the Barrett-Joyner-Halenda (BJH) method, thermogravimetric analysis (TG) and differential thermal analysis (DTA) confirmed the formation of the spinel phase and high purity for all samples. N2 adsorption/desorption and size pore distribution confirmed the high surface area. The photocatalytic activity of Zn1-xMxAl2O4 and the effect of replacing Zn2+ ions with Ni2+ and Co2+ on the degradation of rhodamine B under ultraviolet light were studied in detail. The sample containing 0.1 mol of cobalt had the highest removal rate reaching 83%, favored by surface area and material bandgap (109 m2 g−1 and 2.19 eV, respectively).

Development of α-Fe2O3 as Adsorbent and its Effect on CO2 Capture

2016 ◽  
Vol 840 ◽  
pp. 421-426 ◽  
Author(s):  
Azizul Hakim ◽  
Tengku Sharifah Marliza ◽  
Maratun Najiha Abu Tahari ◽  
Muhammad Rahimi Yusop ◽  
Mohamed Wahab Mohamed Hisham ◽  
...  
Keyword(s):  
Particle Size ◽  
Adsorption Capacity ◽  
Surface Area ◽  
Co2 Adsorption ◽  
High Surface ◽  
High Surface Area ◽  
N2 Adsorption ◽  
Mixing Method ◽  
Desorption Isotherms ◽  
Adsorption Desorption

Iron oxide (α-Fe2O3) as adsorbent was no longer new in CO2 adsorption studies. However, its contributions in the industry still in limited wherein lack of convincing results of quantifying of adsorbed CO2. This work presents an analysis for α-Fe2O3 was prepared by simple mixing method with identified the adsorption capacity that applied in CO2 capture. The synthesized α-Fe2O3 from different concentrations of precursor were analyzed using XRD, N2 adsorption-desorption isotherms with BET and BJH method, TEM, FTIR, CO2 adsorption at 298 K, CO2-TPD and TGA-DTG. It was noted that 2M concentration of precursor (s2M) with highest crystallite peaks shows highest surface area among all samples which indicative of well generated pores. The different concentration of precursor was found generated more porosity rather than particle size according to TEM micrograph. The sphere shape crystallite particle with high surface area (50.5 m2/g) and porosity were desirable properties in CO2 adsorption. Consequently, physically adsorbed CO2 with adsorption at 298 K was highest with adsorption capacity of at 17.0 mgCO2/gadsorbent. Finally, chemically adsorbed CO2 was successfully identified from CO2–TPD analysis with adsorption capacity of 0.19 mgCO2/gadsorbent and 1.31 mgCO2/gadsorbent at maximum desorption temperature of 375 °C and 749 °C respectively.

scholarly journals Synthesis of Bi2O3 Nanosheets and Photocatalysis for Rhodamine B

2019 ◽  
Vol 26 (1) ◽  
pp. 20-24
Author(s):  
Wenwen ZHANG ◽  
Shaomin GAO ◽  
Donghui CHEN
Keyword(s):  
Surface Area ◽  
Rhodamine B ◽  
Diffuse Reflectance ◽  
Photocatalytic Performance ◽  
High Surface ◽  
High Surface Area ◽  
N2 Adsorption ◽  
Simple Method ◽  
Adsorption Desorption ◽  
Liquid Precipitation

Bi2O3 nanosheets (NSB) photocatalyst was fabricated via a very simple method of liquid precipitation. The as obtained products were characterized by SEM, N2 adsorption-desorption, XRD and UV-vis diffuse reflectance spectra. The results showed that NSB catalyst can beconsidered as set of nanosheets with an average thickness of 110 nm. NSB photocatalyst exhibited high surface area of 33.21 m2/g and high purity. In addition, NSB catalyst displayed excellent photocatalytic performance for the dye of rhodamine B (Rh B) under visible light due to the structure of sheet and high surface area.

scholarly journals Investigation of the Catalytic Performance of a Novel Nickel/Kit-6 Nanocatalyst for the Hydrogenation of Vegetable Oil

2012 ◽  
Vol 2012 ◽  
pp. 1-6
Author(s):  
M. A. Usman ◽  
T. O. Alaje ◽  
V. I. Ekwueme ◽  
E. A. Awe
Keyword(s):  
Vegetable Oil ◽  
Activated Carbons ◽  
High Surface ◽  
High Surface Area ◽  
Catalytic Performance ◽  
Impregnation Method ◽  
Wet Impregnation ◽  
Ordered Mesoporous Materials ◽  
Ordered Mesoporous ◽  
Wet Impregnation Method

Highly ordered mesoporous materials are opening the door to new opportunities in catalysis due to their extraordinary intrinsic features. In this study, Nickel was supported on highly ordered mesoporous silica (KIT-6) by the wet impregnation method, and its performance in the hydrogenation of edible vegetable oil was compared with that of Ni/Activated carbon prepared using the same method as well as with unsupported Nickel. The degree of conversion for the 50 : 50 Ni/KIT-6 was 81%, as compared to the 29% obtained with 50 : 50 Ni/Activated carbons. The conversion was found to improve with an increase in mass of supported Nickel on KIT-6 thus 20 : 80 Ni/KIT-6 and 30 : 70 Ni/KIT-6 produced conversions of 71% and 74%, respectively. Key among the benefits of KIT-6 when used as a support material is the very high surface area, open framework of the 3D bicontinuous interconnected channels, and the well-ordered mesopores which bestow on it an advanced mass transfer characteristics.

Hydrothermal and Thermal Decomposition Synthesis of Hierarchical NiO Microspheres with Mesoporous Structure

2011 ◽  
Vol 239-242 ◽  
pp. 252-258
Author(s):  
Hui Liu ◽  
Guang Jun Li ◽  
Jun Qi Li ◽  
Na Wei ◽  
Zhen Feng Zhu
Keyword(s):  
Thermal Decomposition ◽  
Surface Area ◽  
High Surface ◽  
High Surface Area ◽  
Mesoporous Structure ◽  
Structural Features ◽  
Mesoporous Alumina ◽  
N2 Adsorption ◽  
Adsorption Desorption ◽  
Adsorptive Properties

A facile method has been developed to synthesis hierarchical nickel oxide with spherical particle morphologies, high surface area of 234 m2/g and narrow pore distribution at 3.25 nm by controlled thermal decomposition of the nickel nitrate hydroxide precursors. The as-obtained products were well characterized by XRD, SEM, TEM (HRTEM), SAED, FTIR and N2 adsorption-desorption measurement. It was shown that the hierarchical NiO microsphere with the diameter about 2.0 μm is composed of hexagonal nanoparticles with mesoporous structure. The prepared mesoporous materials were used as an adsorbent to remove the Congo red pollutant contained in the waste water, and they exhibited more favorable adsorptive properties than the mesoporous alumina powders with same surface area due to its special structural features.

Structure and composition of metal particles in Pt-Sn/Al2O3 bimetallic catalysts

1990 ◽  
Vol 48 (4) ◽  
pp. 278-279
Author(s):  
A. Sachdev ◽  
J. Schwank
Keyword(s):  
Bimetallic Catalysts ◽  
Bimetallic Catalyst ◽  
Size Structure ◽  
High Surface ◽  
High Surface Area ◽  
Metal Particles ◽  
Alloy Formation ◽  
Particle Size Range ◽  
Oxide Supports ◽  
Petroleum Fractions

Platinum - tin bimetallic catalysts have been primarily utilized in the chemical industry in the catalytic reforming of petroleum fractions. In this process the naphtha feedstock is converted to hydrocarbons with higher octane numbers and high anti-knock qualities. Most of these catalysts contain small metal particles or crystallites supported on high surface area insulating oxide supports. The determination of the structure and composition of these particles is crucial to the understanding of the catalytic behavior. In a bimetallic catalyst it is important to know how the two metals are distributed within the particle size range and in what way the addition of a second metal affects the size, structure and composition of the metal particles. An added complication in the Pt-Sn system is the possibility of alloy formation between the two elements for all atomic ratios.

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