Catalytic Properties of Ni/CNTs and Ca-Promoted Ni/CNTs for Methanation Reaction of Carbon Dioxide

Nickel/carbon nanotubes (Ni/CNTs), Nickel/alumina (Ni/Al2O3), calcium-promoted Ni/CNTs and calcium-promoted Ni/Al2O3 were synthesized by impregnation method. Methanation of carbon dioxide was used as a probe to evaluate their catalytic performance. The features of these Ni-based catalysts were investigated via XRD, H2-TPR, H2-TPD and the N2 adsorptiondesorption isotherms. H2-TPR showed that nickel species on Ni/CNTs was reduced more easily with respect to that on Ni/Al2O3, and addition of Ca can increase the content of easily reducible Ni species for Ni/CNTs. XRD and H2-TPD indicated that addition of Ca promoted dispersion for CNTs-supported catalyst. These finding ultimately enhanced catalytic activity and stability for Ni/CNTs catalyst modified with Ca.

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The Effect of MgO Precoating on the Perfomance of Ni/MgO-Al2O3 Catalysts for Carbon Dioxide Reforming of Methane

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.997.272 ◽

2014 ◽

Vol 997 ◽

pp. 272-278 ◽

Cited By ~ 1

Author(s):

Li Qiong Huang ◽

Zheng Hui Zhang ◽

Zhang Long Guo

Keyword(s):

Carbon Dioxide ◽

Surface Area ◽

Active Sites ◽

Impregnation Method ◽

X Ray Diffraction ◽

Carbon Dioxide Reforming ◽

Temperature Programmed ◽

Ni Species ◽

Adsorption Desorption ◽

Nickel Species

Ni catalysts supported on γ?-Al2O3 supports modified by different MgO precoating weight were prepared by impregnation method. The surface area, pore diameter and Ni crystallite size were investigated by N2 adsorption/desorption (BET) and X-ray diffraction (XRD) methods. The reducing temperature and quantity information of reducible nickel species were obtained by H2-TPR experiments. The CO2 adsorption/desorption abilities of catalysts were investigated and the activity of catalysts were also measured. The coke resistance performance of catalysts for carbon dioxide reforming of methane (CDRM) was studied by CO2 temperature programmed surface reaction (CO2-TPSR). H2-TPR results revealed that there were three kinds of Ni species on the supports. Appropriate modification amount of MgO could increase the surface nickel active sites which could be easily reduced and prevented the formation of NiAl2O4 spinel species. CO2-TPD indicated that the addition of MgO increased the amount of CO2 adsorption at lower temperatures. N2 adsorption/desorption results disclosed that the excessive modification of MgO would decrease the surface area and pore size of the samples. The reforming reaction results showed that the activity was elevated from 58.62% to 65.95% over the Ni/MgO-Al2O3 when the Mg/Al ratio was 0.05 (wt.) and there was less coke evidenced by the CO2-TPSR results comparing to the Ni/γ?-Al2O3 catalyst.

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Influence of the Reduction Temperature and the Nature of the Support on the Performance of Zirconia and Alumina-Supported Pt Catalysts for n-Dodecane Hydroisomerization

Catalysts ◽

10.3390/catal11010088 ◽

2021 ◽

Vol 11 (1) ◽

pp. 88

Author(s):

Diana García-Pérez ◽

Maria Consuelo Alvarez-Galvan ◽

Jose M. Campos-Martin ◽

Jose L. G. Fierro

Keyword(s):

Catalytic Activity ◽

Surface Area ◽

Catalytic Properties ◽

Catalytic Performance ◽

Major Influence ◽

Pt Catalysts ◽

Reduction Temperature ◽

Metal Dispersion ◽

Tungsten Oxides ◽

Supported Pt Catalysts

Catalysts based on zirconia- and alumina-supported tungsten oxides (15 wt % W) with a small loading of platinum (0.3 wt % Pt) were selected to study the influence of the reduction temperature and the nature of the support on the hydroisomerization of n-dodecane. The reduction temperature has a major influence on metal dispersion, which impacts the catalytic activity. In addition, alumina and zirconia supports show different catalytic properties (mainly acid site strength and surface area), which play an important role in the conversion. The NH3-TPD profiles indicate that the acidity in alumina-based catalysts is clearly higher than that in their zirconia counterparts; this acidity can be attributed to a stronger interaction of the WOx species with alumina. The PtW/Al catalyst was found to exhibit the best catalytic performance for the hydroisomerization of n-dodecane based on its higher acidity, which was ascribed to its larger surface area relative to that of its zirconia counterparts. The selectivity for different hydrocarbons (C7–10, C11 and i-C12) was very similar for all the catalysts studied, with branched C12 hydrocarbons being the main products obtained (~80%). The temperature of 350 °C was clearly the best reduction temperature for all the catalysts studied in a trickled-bed-mode reactor.

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CO2 valorization into synthetic natural gas (SNG) using a Co–Ni bimetallic Y2O3 based catalysts

International Journal of Chemical Reactor Engineering ◽

10.1515/ijcre-2020-0163 ◽

2021 ◽

Vol 0 (0) ◽

Author(s):

Radwa A. El-Salamony ◽

Sara A. El-Sharaky ◽

Seham A. Al-Temtamy ◽

Ahmed M. Al-Sabagh ◽

Hamada M. Killa

Keyword(s):

Reaction Mechanism ◽

Natural Gas ◽

Fixed Bed ◽

Catalytic Performance ◽

Fixed Bed Reactor ◽

Molar Ratio ◽

Impregnation Method ◽

Synthetic Natural Gas ◽

Methanation Reaction ◽

Co2 Valorization

Abstract Recently, because of the increasing demand for natural gas and the reduction of greenhouse gases, interests have focused on producing synthetic natural gas (SNG), which is suggested as an important future energy carrier. Hydrogenation of CO2, the so-called methanation reaction, is a suitable technique for the fixation of CO2. Nickel supported on yttrium oxide and promoted with cobalt were prepared by the wet-impregnation method respectively and characterized using SBET, XRD, FTIR, XPS, TPR, and HRTEM/EDX. CO2 hydrogenation over the Ni/Y2O3 catalyst was examined and compared with Co–Ni/Y2O3 catalysts, Co% = 10 and 15 wt/wt. The catalytic test was conducted with the use of a fixed-bed reactor under atmospheric pressure. The catalytic performance temperature was 350 °C with a supply of H2:CO2 molar ratio of 4 and a total flow rate of 200 mL/min. The CH4 yield was reached 67%, and CO2 conversion extended 48.5% with CO traces over 10Co–Ni/Y2O3 catalyst. This encourages the direct methanation reaction mechanism. However, the reaction mechanism over Ni/Y2O3 catalyst shows different behaviors rather than that over bi-metal catalysts, whereas the steam reforming of methane reaction was arisen associated with methane consumption besides increase in H2 and CO formation; at the same temperature reaction.

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Performance Analysis of TiO2-Modified Co/MgAl2O4 Catalyst for Dry Reforming of Methane in a Fixed Bed Reactor for Syngas (H2, CO) Production

Energies ◽

10.3390/en14113347 ◽

2021 ◽

Vol 14 (11) ◽

pp. 3347

Author(s):

Arslan Mazhar ◽

Asif Hussain Khoja ◽

Abul Kalam Azad ◽

Faisal Mushtaq ◽

Salman Raza Naqvi ◽

...

Keyword(s):

Catalytic Activity ◽

Fixed Bed ◽

Catalytic Performance ◽

Dry Reforming ◽

Fixed Bed Reactor ◽

Dry Reforming Of Methane ◽

Catalyst Stability ◽

Feed Ratio ◽

Catalyst Loading ◽

Impregnation Method

Co/TiO2–MgAl2O4 was investigated in a fixed bed reactor for the dry reforming of methane (DRM) process. Co/TiO2–MgAl2O4 was prepared by modified co-precipitation, followed by the hydrothermal method. The active metal Co was loaded via the wetness impregnation method. The prepared catalyst was characterized by XRD, SEM, TGA, and FTIR. The performance of Co/TiO2–MgAl2O4 for the DRM process was investigated in a reactor with a temperature of 750 °C, a feed ratio (CO2/CH4) of 1, a catalyst loading of 0.5 g, and a feed flow rate of 20 mL min−1. The effect of support interaction with metal and the composite were studied for catalytic activity, the composite showing significantly improved results. Moreover, among the tested Co loadings, 5 wt% Co over the TiO2–MgAl2O4 composite shows the best catalytic performance. The 5%Co/TiO2–MgAl2O4 improved the CH4 and CO2 conversion by up to 70% and 80%, respectively, while the selectivity of H2 and CO improved to 43% and 46.5%, respectively. The achieved H2/CO ratio of 0.9 was due to the excess amount of CO produced because of the higher conversion rate of CO2 and the surface carbon reaction with oxygen species. Furthermore, in a time on stream (TOS) test, the catalyst exhibited 75 h of stability with significant catalytic activity. Catalyst potential lies in catalyst stability and performance results, thus encouraging the further investigation and use of the catalyst for the long-run DRM process.

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Effect of Fe Additives on the Catalytic Performance of Ion-Exchanged CsX Zeolites for Side-Chain Alkylation of Toluene with Methanol

Catalysts ◽

10.3390/catal9100829 ◽

2019 ◽

Vol 9 (10) ◽

pp. 829 ◽

Cited By ~ 4

Author(s):

Zhang ◽

Yuan ◽

Miao ◽

Li ◽

Shan ◽

...

Keyword(s):

Catalytic Activity ◽

Catalytic Performance ◽

High Yield ◽

Side Chain ◽

Impregnation Method ◽

Basic Sites ◽

Lewis Acidic Sites ◽

X Zeolite ◽

Acidic Sites ◽

Negative Effect

The side-chain alkylation of toluene with methanol was investigated over some Fe-modified Cs ion-exchanged X zeolite (CsX) catalysts prepared via the impregnation method using different iron sources. The absorption/activation behaviors of the reactants on the surface of the catalysts were studied by in situ Fourier-transform infrared (FT-IR) spectroscopy and temperature programmed desorption (TPD) mass measurements. Modification of CsX with a small amount of FeCl3 could result in a considerable decrease in catalytic activity, due mainly to the remarkable decrease in the density of acidic and basic sites of the catalysts. Interestingly, the Fe(NO3)3-modified CsX with an optimum Fe loading of 0.15 wt.% shows improved catalytic activity and high yield compared to the side-chain alkylation products. Modification of CsX with Fe(NO3)3 could also result in a decrease in basic sites of the catalyst. However, such a change does not bring an obvious negative effect on the adsorption/activation of toluene, while it could effectively inhibit the generation of the undesired bidentate formate. Furthermore, the introduced FeOx species (derived from the decomposition of Fe(NO3)3) may also act as new Lewis acidic sites to participate in the activation of methanol and to stabilize the formed active intermediates (i.e., unidentate formate). Therefore, modification of CsX with a suitable amount of Fe(NO3)3 may adjust its adsorption/activation ability for reagents by changing the acid–base properties of the catalyst, which can finally enhance the catalytic performance for the side-chain alkylation of toluene with methanol.

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Preparation of Ni/ZrO2/SiO2 Catalyst and its Application in Hydrogenation of CO2 to Methane

Materials Science Forum ◽

10.4028/www.scientific.net/msf.1001.79 ◽

2020 ◽

Vol 1001 ◽

pp. 79-83

Author(s):

Zhen Xing Han ◽

Si Xi Guo ◽

Kai Ming Li ◽

Bing Yao ◽

Ming Song ◽

...

Keyword(s):

Catalytic Activity ◽

Low Temperature ◽

Catalytic Performance ◽

Experimental Results ◽

Impregnation Method ◽

Energy And Environment ◽

Supported Ni ◽

Hydrogenation Of Co

The hydrogenation of CO2 to CH4 can realize the utilization of CO2, which has an important implications to both the energy and environment. As a result of the low catalytic activity of the supported Ni/SiO2 catalyst, the ZrO2 is added to improve its catalytic performance by the impregnation method. The experimental results show that ZrO2 is an effective promoter to enhance the low-temperature catalytic activity of Ni/SiO2 catalyst.

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Impact of double-solvent impregnation on the Ni dispersion of Ni/SBA-15 catalysts and catalytic performance for the syngas methanation reaction

RSC Advances ◽

10.1039/c6ra04490e ◽

2016 ◽

Vol 6 (42) ◽

pp. 35875-35883 ◽

Cited By ~ 20

Author(s):

Miao Tao ◽

Zhong Xin ◽

Xin Meng ◽

Yuhao Lv ◽

Zhicheng Bian

Keyword(s):

Catalytic Performance ◽

Impregnation Method ◽

Co Methanation ◽

Methanation Reaction ◽

Excellent Activity

Ni/SBA-15 prepared by a double-solvent impregnation method showed excellent activity for CO methanation and catalyst sintering was the main cause of deactivation.

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Carbon Dioxide Reforming of Methane over Ni Supported SiO2: Influence of the Preparation Method on the Resulting Structural Properties and Catalytic Activity

Catalysts ◽

10.3390/catal10070795 ◽

2020 ◽

Vol 10 (7) ◽

pp. 795 ◽

Cited By ~ 1

Author(s):

Hua-Ping Ren ◽

Shao-Peng Tian ◽

Si-Yi Ding ◽

Gui-Qiu Huang ◽

Min Zhu ◽

...

Keyword(s):

Carbon Dioxide ◽

Particle Size ◽

Catalytic Activity ◽

Citric Acid ◽

Preparation Method ◽

Complexing Agents ◽

Impregnation Method ◽

Carbon Dioxide Reforming ◽

Highly Active ◽

Before And After

Ni-C/SiO2 and Ni-G/SiO2 catalysts were prepared by a complexed-impregnation method using citric acid and glycine as complexing agents, respectively. Ni/SiO2 was also prepared by the conventional incipient impregnation method. All the catalysts were comparatively tested for carbon dioxide reforming of methane (CDR) at P = 1.0 atm, T = 750 °C, CO2/CH4 = 1.0, and GHSV = 60,000 mL·g−1·h−1. The results showed that Ni-C/SiO2 and Ni-G/SiO2 exhibited better CDR performance, especially regarding stability, than Ni/SiO2. The conversions of CH4 and CO2 were kept constant above 82% and 87% after 20 h of reaction over Ni-C/SiO2 and Ni-G/SiO2 while they were decreased from 81% and 88% to 56% and 59%, respectively, over the Ni/SiO2. The characterization results of the catalysts before and after the reaction showed that the particle size and the distribution of Ni, as well as the interactions between Ni and the support were significantly influenced by the preparation method. As a result, an excellent resistance to the coking deposition and the anti-sintering of Ni was obtained over the Ni-C/SiO2 and Ni-G/SiO2, leading to a highly active and stable CDR performance.

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Influence of Co2 on the Catalytic Performance Of La2O3/CeO2 and CaO/CeO2 Catalysts in the Oxidative Coupling of Methane

Polish Journal of Chemical Technology ◽

10.2478/pjct-2013-0005 ◽

2013 ◽

Vol 15 (1) ◽

pp. 22-26 ◽

Cited By ~ 5

Author(s):

Barbara Litawa ◽

Piotr Michorczyk ◽

Jan Ogonowski

Keyword(s):

Oxidative Coupling ◽

Methane Conversion ◽

Catalytic Properties ◽

Catalytic Performance ◽

Negative Influence ◽

Oxidative Coupling Of Methane ◽

Oxygen Mixture ◽

Impregnation Method ◽

Promoting Effect ◽

Conversion Of Methane

In this work the La2O3/CeO2 (33 mol % of La) and CaO/CeO2 (33 mol % of Ca) catalysts were prepared by the impregnation method and characterized by XRD and CO2-TPD. The catalytic properties of the catalysts were tested in the OCM process at 1073 K using the methane/oxygen mixture of the mole ratio 3.7 or 2.5 additionally containing CO2 and helium balance. It was found that in the presence of both catalysts an addition of CO2 enhances the selectivity to the ethylene and ethane and it does not have any negative influence on methane conversion. In the case of the CaO/CeO2 catalyst the promoting effect of CO2 was the highest. When the partial pressure of CO2 equals to 39 kPa the increase in selectivity from 36 to 41% was noted while the conversion of methane equal to 19.4-19.7 %.

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Enhanced Catalytic Activity of Carbon Nanotubes for the Oxidation of Cyclohexane by Filling with Fe, Ni, and FeNi alloy Nanowires

Australian Journal of Chemistry ◽

10.1071/ch15516 ◽

2016 ◽

Vol 69 (6) ◽

pp. 689 ◽

Cited By ~ 4

Author(s):

Xixian Yang ◽

Yuhang Li ◽

Hao Yu ◽

Xuchun Gui ◽

Hongjuan Wang ◽

...

Keyword(s):

Carbon Nanotubes ◽

Catalytic Activity ◽

Wall Thickness ◽

Density Functional ◽

Density Functional Theory Calculations ◽

Catalytic Performance ◽

General Strategy ◽

Thin Walls ◽

Alloy Nanowires ◽

Relationship Of

Fe-, Ni-, and alloyed FeNi-filled carbon nanotubes (Fe@CNT, Ni@CNT, and FeNi@CNT) were prepared by a general strategy using a mixture of xylene and dichlorobenzene as carbon source, and ferrocene, nickelocene, and their mixture as catalysts. By tailoring the composition of the carbon precursor, the filling ratio and the wall thickness of metal@CNT could be controlled. For the catalytic oxidation of cyclohexane in liquid phase with molecular oxygen as oxidant, the highest activity was obtained over Fe@CNT synthesized from pure dichlorobenzene. However, Ni filling did not improve the activity of CNTs. The effects of metal filling, wall thickness, and defects on catalytic activity were investigated to determine the structure–activity relationship of the filled CNTs. The enhanced catalytic performance can be attributed to a combined contribution of thin walls of CNTs and confined electron-donating metals, which are favourable to electron transfer on the surfaces of CNTs. The modification of the electronic structure of CNTs upon Fe and Ni fillers insertion was elucidated through density functional theory calculations.

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