scholarly journals CO2 Methanation over Ni/Al@MAl2O4 (M = Zn, Mg, or Mn) Catalysts

Catalysts ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 599 ◽  
Author(s):  
Le ◽  
Kim ◽  
Jeong ◽  
Park
Keyword(s):  
Surface Oxidation ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Core Shell ◽  
Ni Doping ◽  
Ni Catalysts ◽  
Co2 Methanation ◽  
Temperature Programmed ◽  
Diffuse Reflectance Infrared ◽  
Spinel Structures

In this study, unique core-shell aluminate spinel supports, Al@MAl2O4 (M = Zn, Mg, or Mn), were obtained by simple hydrothermal surface oxidation and were applied to the preparation of supported Ni catalysts for CO2 methanation. For comparison, CO methanation was also evaluated using the same catalysts. The prepared catalysts were characterized with a variety of techniques, including N2 physisorption, CO2 chemisorption, H2 chemisorption, temperature-programmed reduction with H2, temperature-programmed desorption of CO2, X-ray diffraction, high-resolution transmission electron microscopy, and in-situ diffuse reflectance infrared Fourier transform spectroscopy. The combination of supports with core-shell spinel structures and Ni doping with a deposition–precipitation method created outstanding catalytic performance of the Ni catalysts supported on Al@MgAl2O4 and Al@MnAl2O4 due to improved dispersion of Ni nanoparticles and creation of moderate basic sites with suitable strength. Good stability of Ni/Al@MnAl2O4 catalyst was also confirmed in the study.

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.

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.

Preparation and Ultra-Deep Hydrorefining Performance of Ni-P/Al2O3-ZrO2 Catalysts

2011 ◽  
Vol 236-238 ◽  
pp. 724-727
Author(s):  
Feng Li ◽  
Hua Song ◽  
Hua Yang Zhang
Keyword(s):  
Chemical Precipitation ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
X Ray ◽  
Molar Ratios ◽  
Thiophene Hydrodesulfurization ◽  
Composite Oxides ◽  
Temperature Programmed ◽  
Supported Ni

A series of Al2O3-ZrO2 (AZ-X) composite oxides with different ZrO2 contents were prepared by a chemical precipitation method. Ni-P/AZ-X catalysts were prepared by temperature-programmed reduction. The supports and catalysts were extensively characterized by X-ray diffraction (XRD) and BET. The effects of support composition and P/Ni molar ratios on the catalytic performance of the catalysts were investigated by thiophene hydrodesulfurization (HDS) and pyridine hydrodenitrogenation (HDN). In comparison with Al2O3, Al2O3-ZrO2 (20 wt% ZrO2) composite oxide supported Ni-P catalyst exhibited higher activity and the activities of HDS and HDN increased by 7.5 % and 11.1 %, respectively. Studies of Ni-P/AZ-X catalysts with varying initial P/Ni molar ratios indicated that oxidic precursors with molar ratios of P/Ni = 2/1 yielded catalyst containing phase-pure Ni2P which exhibited optimal activity.

scholarly journals Investigation on the Suitability of Engelhard Titanium Silicate as a Support for Ni-Catalysts in the Methanation Reaction

Catalysts ◽  
2021 ◽  
Vol 11 (10) ◽  
pp. 1225
Author(s):  
Patrizia Frontera ◽  
Mariachiara Miceli ◽  
Francesco Mauriello ◽  
Pierantonio De Luca ◽  
Anastasia Macario
Keyword(s):  
Catalytic Performance ◽  
Titanium Content ◽  
Low Grade ◽  
Ni Catalysts ◽  
Titanium Silicate ◽  
Co2 Methanation ◽  
Methanation Reaction ◽  
Titanium Silicates ◽  
Adsorption Desorption ◽  
Catalytic Performances

Methanation reaction of carbon dioxide is currently envisaged as a facile solution for the storage and transportation of low-grade energies, contributing at the same time to the mitigation of CO2 emissions. In this work, a nickel catalyst impregnated onto a new support, Engelhard Titanium Silicates (ETS), is proposed, and its catalytic performance was tested toward the CO2 methanation reaction. Two types of ETS material were investigated, ETS-4 and ETS-10, that differ from each other in the titanium content, with Si/Ti around 2 and 3% by weight, respectively. Catalysts, loaded with 5% of nickel, were tested in the CO2 methanation reaction in the temperature range of 300–500 °C and were characterized by XRD, SEM–EDX, N2 adsorption–desorption and H2-TPR. Results showed an interesting catalytic activity of the Ni/ETS catalysts. Particularly, the best catalytic performances are showed by Ni/ETS-10: 68% CO2 conversion and 98% CH4 selectivity at T = 400 °C. The comparison of catalytic performance of Ni/ETS-10 with those obtained by other Ni-zeolites catalysts confirms that Ni/ETS-10 catalyst is a promising one for the CO2 methanation reaction.

Catalytic performance of Ni catalysts supported on CeO2 with different morphologies for low-temperature CO2 methanation

2020 ◽  
Author(s):  
Thapanee Jomjaree ◽  
Paweennut Sintuya ◽  
Atthapon Srifa ◽  
Wanida Koo-amornpattana ◽  
Sirapassorn Kiatphuengporn ◽  
...  
Keyword(s):  
Low Temperature ◽  
Catalytic Performance ◽  
Ni Catalysts ◽  
Co2 Methanation

scholarly journals Three-Dimensional Mesoporous Ni-CeO2 Catalysts with Ni Embedded in the Pore Walls for CO2 Methanation

Catalysts ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 523 ◽  
Author(s):  
Luhui Wang ◽  
Junang Hu ◽  
Hui Liu ◽  
Qinhong Wei ◽  
Dandan Gong ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Nitrogen Adsorption ◽  
Combustion Method ◽  
Catalytic Performance ◽  
Oxide Interface ◽  
Solution Combustion ◽  
Co2 Methanation ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Adsorption Desorption

Mesoporous Ni-based catalysts with Ni confined in nanochannels are widely used in CO2 methanation. However, when Ni loadings are high, the nanochannels are easily blocked by nickel particles, which reduces the catalytic performance. In this work, three-dimensional mesoporous Ni-CeO2-CSC catalysts with high Ni loadings (20−80 wt %) were prepared using a colloidal solution combustion method, and characterized by nitrogen adsorption–desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM) and H2 temperature programmed reduction (H2-TPR). Among the catalysts with different Ni loadings, the 50% Ni-CeO2-CSC with 50 wt % Ni loading exhibited the best catalytic performance in CO2 methanation. Furthermore, the 50% Ni-CeO2-CSC catalyst was stable for 50 h at 300° and 350 °C in CO2 methanation. The characterization results illustrate that the 50% Ni-CeO2-CSC catalyst has Ni particles smaller than 5 nm embedded in the pore walls, and the Ni particles interact with CeO2. On the contrary, the 50% Ni-CeO2-CP catalyst, prepared using the traditional coprecipitation method, is less active and selective for CO2 methanation due to the larger size of the Ni and CeO2 particles. The special three-dimensional mesoporous embedded structure in the 50% Ni-CeO2-CSC can provide more metal–oxide interface and stabilize small Ni particles in pore walls, which makes the catalyst more active and stable in CO2 methanation.

scholarly journals Novel Nano-Fe2O3-Co3O4 Modified Dolomite and Its Use as Highly Efficient Catalyst in the Ozonation of Ammonium Solution

2020 ◽  
Vol 2020 ◽  
pp. 1-11
Author(s):  
Manh B. Nguyen ◽  
Giang H. Le ◽  
Trang T. T. Pham ◽  
Giang T. T. Pham ◽  
Trang T. T. Quan ◽  
...  
Keyword(s):  
Catalytic Performance ◽  
Catalytic Ozonation ◽  
Precipitation Method ◽  
X Ray Diffraction ◽  
Kcal Mole ◽  
Efficient Catalyst ◽  
X Ray ◽  
Sem Image ◽  
Temperature Programmed ◽  
Adsorption Desorption

Catalytic ozonation is a new method used for removal of NH4OH solution. Therefore, high catalytic performance (activity and selectivity) should be achieved. In this work, we report the synthesis and catalytic performance of Fe2O3-Co3O4 modified dolomite in the catalytic ozonation of NH4OH solution. Dolomite was successfully activated and modified with Fe2O3 and Co3O4. Firstly, dolomite was activated by heating at 800°C for 3 h and followed by KOH treatment. Activated dolomite was modified with Fe2O3 by the atomic implantation method using FeCl3 as Fe source. Fe2O3 modified dolomite was further modified with Co3O4 by precipitation method. The obtained catalysts were characterized by X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N2 adsorption–desorption (BET), and temperature-programmed reduction (H2-TPR). From SEM image, it was revealed that nano-Fe2O3 and Co3O4 particles with the size of 80–120 nm. Catalytic performance of activated dolomite, Fe2O3 modified dolomite, and Fe2O3-Co3O4 modified dolomite in catalytic ozonation of NH4+ solution was investigated and evaluated. Among 3 tested catalysts, Fe2O3-Co3O4 modified dolomite has the highest NH4+ conversion (96%) and N2 selectivity (77.82%). Selectivity toward N2 over the catalyst was explained on the basis of bond strength M-O in oxides through the standard enthalpy ΔH°f of oxide. Catalyst with lower ΔH°f value has higher N2 selectivity and the order is the following: Co3O4 (ΔH°f of 60 kcal (mole O)) > Fe2O3 (ΔH°f of 70 kcal (mole O)) > MgO (ΔH°f of 170 kcal (mole O)). Moreover, high reduction ability of Fe2O3-Co3O4 modified dolomite could improve the N2 selectivity by the reduction of NO3- to N2 gas.

The Reduction Properties of Hexa Aluminates Substituted by Different Metal Ions for Denitrification System

2013 ◽  
Vol 734-737 ◽  
pp. 2364-2368
Author(s):  
Xiao Guang Ren ◽  
Fu Xia Li ◽  
Peng Li ◽  
Wei Hou
Keyword(s):  
Metal Ions ◽  
Surface Area ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Temperature Programmed ◽  
Co Precipitation

In this study, the hexaaluminate catalyst SrMnMAl10O19-δ（M= Cd、Co、Cu 、Fe、Ni、Zn、Zr、Cr and Y）and SrMnFexAl11-xO19-δ(x=1, 2, 4, 6, 8)have been prepared by co-precipitation method. The catalysts were characterized by powder X-ray diffraction (XRD), surface area (BET), hydrogen temperature programmed reduction (H2-TPR). The reduction catalyst properties of hexaaluminate for deNOx were evaluated by using devices of micro-evaluation. The results showed that the CO could remove NOx very well. The hexaaluminate not only have a good catalytic performance, but also can form a complete crystal calcined at 1200 °C for 4 h.

scholarly journals Preferential Oxidation of CO over CoFe2O4 and M/CoFe2O4 (M = Ce, Co, Cu or Zr) Catalysts

Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 15
Author(s):  
Mehdi Béjaoui ◽  
Abdelhakim Elmhamdi ◽  
Laura Pascual ◽  
Patricia Pérez-Bailac ◽  
Kais Nahdi ◽  
...  
Keyword(s):  
Co Oxidation ◽  
Sol Gel ◽  
Catalytic Performance ◽  
Photoelectron Spectra ◽  
X Ray ◽  
Preferential Oxidation Of Co ◽  
Transmission Electron ◽  
Low Temperature Co Oxidation ◽  
Temperature Programmed ◽  
Diffuse Reflectance Infrared

CoFe2O4 prepared by sol-gel has been examined with respect to its catalytic performance for preferential CO oxidation in a H2-rich stream. In turn, the promoting effects of incorporation of Ce, Co, Cu, and Zr by impregnation on the surface of CoFe2O4 on the process are examined as well. The catalysts have been characterized by N2 adsorption, X-ray diffraction (XRD), high resolution transmission electron microscopy (HRTEM), temperature programmed reduction (TPR), and X-ray photoelectron spectra (XPS), as well as diffuse reflectance infrared DRIFTS under reaction conditions with the aim of establishing structure/activity relationships for the mentioned catalyst/process. It is shown that while the presence of the various metals on CoFe2O4 hinders a low temperature CO oxidation process, it appreciably enhances the activity above 125 °C. This is basically attributed to the surface modifications, i.e. cobalt oxidation, induced in CoFe2O4 upon introduction of the metals. In turn, no methanation activity is observed in any case except for the copper-containing catalyst, in which achievement of reduced states of cobalt appears most favored.

Effect of Aging Methods on CuZnAl Catalysts for Methyl Acetate Hydrogenation

2019 ◽  
Vol 72 (6) ◽  
pp. 417
Author(s):  
Changna Gan ◽  
Yunhao Wang ◽  
Chenliang Ye ◽  
Cuili Guo
Keyword(s):  
Photoelectron Spectroscopy ◽  
Inductively Coupled Plasma ◽  
Methyl Acetate ◽  
Copper Particle ◽  
Atomic Emission ◽  
Catalytic Performance ◽  
Precipitation Method ◽  
Molar Ratio ◽  
X Ray ◽  
Temperature Programmed

A series of CuZnAl catalysts derived from layered double hydroxide precursors with different Cu/Zn molar ratios were synthesised by a co-precipitation method for methyl acetate hydrogenation. The best catalytic performance was obtained when the Cu/Zn molar ratio reached 0.25:1. After fixing the Cu/Zn molar ratio at 0.25:1, the effect of aging methods, including ultrasound, high shear mixer stirring, and magnetic stirring, were investigated, which showed that 0.25CuZnAl-u and 0.25CuZnAl-h exhibited a higher conversion and selectivity than that of 0.25CuZnAl-m, especially under low reaction temperatures. The physicochemical properties of the CuZnAl catalysts were characterised by X-ray diffraction, inductively coupled plasma–atomic emission spectroscopy, N2 physisorption, N2O chemisorption, transmission electron microscopy, H2-temperature-programmed reduction, X-ray photoelectron spectroscopy, and H2-temperature-programmed desorption. It was found that compared with 0.25CuZnAl-m, 0.25CuZnAl-u and 0.25CuZnAl-h possessed a stronger interaction between Cu and the support, smaller copper particle size, and higher copper dispersion, which improved the catalytic performance.

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