Enhancement of CO2 Reforming of CH4 Reaction Using Ni,Pd,Pt/Mg1−xCex4+O and Ni/Mg1−xCex4+O Catalysts

Catalysts Ni/Mg1−xCex4+O and Ni,Pd,Pt/Mg1−xCex4+O were developed using the co-precipitation–impregnation methods. Catalyst characterization took place using XRD, H2-TPR, XRF, XPS, Brunauer–Emmett–Teller (BET), TGA TEM, and FE-SEM. Testing the catalysts for the dry reforming of CH4 took place at temperatures of 700–900 °C. Findings from this study revealed a higher CH4 and CO2 conversion using the tri-metallic Ni,Pd,Pt/Mg1−xCex4+O catalyst in comparison with Ni monometallic systems in the whole temperature ranges. The catalyst Ni,Pd,Pt/Mg0.85Ce4+0.15O also reported an elevated activity level (CH4; 78%, and CO2; 90%) and an outstanding stability. Carbon deposition on spent catalysts was analyzed using TEM and Temperature programmed oxidation-mass spectroscopy (TPO-MS) following 200 h under an oxygen stream. The TEM and TPO-MS analysis results indicated a better anti-coking activity of the reduced catalyst along with a minimal concentration of platinum and palladium metals.

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Effects of the Mg addition on characteristics and catalytic activity of Ni/-Al2O3 in dry reforming of methane

Science and Technology Development Journal - Natural Sciences ◽

10.32508/stdjns.v1it5.538 ◽

2018 ◽

Vol 1 (T5) ◽

pp. 85-94

Author(s):

Loc Cam Luu ◽

Tri Nguyen ◽

Cuong Tien Hoang ◽

Tien Trong Nguyen ◽

Minh Hoang Phan ◽

...

Keyword(s):

Reaction Temperature ◽

Flow Reactor ◽

Coke Formation ◽

Dry Reforming ◽

Dry Reforming Of Methane ◽

Co2 Reforming ◽

Temperature Programmed Oxidation ◽

Co2 Reforming Of Ch4 ◽

Temperature Programmed ◽

Α Al2o3

Effectively using CO2-containing natural gas is an urgent requirement in Vietnam. Therefore, producing hydrogen and syngas by dry reforming of methane (СН4+СО2 = 2Н2+2СО) has gained renewed interest in recent years. In this paper, Ni/α- Al2O3 and Ni-Mg/α-Al2O3 catalysts were prepared by impregnation. Physico-chemical characteristics of catalysts were investigated via nitrogen physisorption (BET), X-Ray Diffraction (XRD), Transmission Electron Microscopy (TEM), and Temperature Programmed Reduction (TPR) methods. The activities of catalysts in CO2 reforming of CH4 were studied in a micro-flow reactor in the temperature range 550 –800oC, and content of CH4 and CO2 of 3 % mol. It was found that the conversion of CH4 and CO2 remarkably increased with the increase of reaction temperature from 550 to 700oC, but increased inconsiderably when the temperature reached more than 700oC. The selectivities of CO and H2 reached over 91 %. The modification of Ni/α- Al2O3 catalyst with Mg led to reduce the NiO particle size forme the new ZnO-MgO solid solution and increase the reductivity of catalyst. These improve the activity, selectivity and stability of catalyst. At the reaction temperature of 700oC, the conversions of CH4 and CO2 on Ni-Mg/α-Al2O3 reached 88.5 % and 72.3 %, respectively. The activities of catalysts were stable for 30 hours of reaction. Moreover, the role of Mg in the resistance to the coke formation on the catalyst surface was clarified via the results of temperature programmed oxidation (TPO) of spent catalysts after running the reaction for 30 hours at 700oC

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CO2 reforming of CH4 over M(Ca, Ba, Sr)xLa1-xNiO3 perovskites used as coke resistant catalyst precursor

Chemical Industry and Chemical Engineering Quarterly ◽

10.2298/ciceq190620040t ◽

2020 ◽

pp. 40-40

Author(s):

Ana Carolina Trevisani Souza ◽

Marcelo da Silva Batista

Keyword(s):

Catalytic Performance ◽

Partial Substitution ◽

High Catalytic Activity ◽

Catalyst Precursor ◽

Co2 Reforming ◽

Temperature Programmed Oxidation ◽

Co2 Reforming Of Ch4 ◽

Co2 Reforming Of Methane ◽

Temperature Programmed ◽

Carbon Dioxide Co2

Methane (CH4) and carbon dioxide (CO2) are greenhouse gases that have been converted into synthesis gas for the production of oxygenated chemicals and hydrocarbons. In this paper, M(Ca, Ba, Sr)xLa1-xNiO3 (x=0.0, 0.3 and 0.5) doped perovskites were successfully synthesized as catalyst precursors aiming at high catalytic activity and stability in the CO2 reforming of methane. These perovskites were characterized by X-ray diffraction (XRD), temperature programmed reduction by H2 (H2-TPR) and O2-temperature programmed oxidation (TPO). Its activity and carbon suppression were investigated in the CO2 reforming of methane. Results showed formation of perovskite structure, but La2NiO4 spinel and NiO were also detected in doped perovskites. The Ca, Ba and Sr partial substitution has evident influence on the reduction behavior of perovskites. All the doped perovskites used as catalyst precursors had better catalytic performance than LaNiO3. However, increasing the doping content decreased activity. Among doped perovskites, Ca0.3La0.7NiO3 showed better catalytic performance for the methane reforming reaction.

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COMBINED STEAM AND CO2 REFORMING OF CH4 OVER NICKEL CATALYSTS BASED ON Al2O3–MO (M= Mg, Ca, Ba)

Vietnam Journal of Science and Technology ◽

10.15625/2525-2518/55/1b/12090 ◽

2018 ◽

Vol 55 (1B) ◽

pp. 49

Author(s):

Phuong P. H.

Keyword(s):

Nickel Catalysts ◽

Precipitation Method ◽

Impregnation Method ◽

Co2 Reforming ◽

Co2 Reforming Of Ch4 ◽

Transmission Electron ◽

Catalytic Stability ◽

Supported Nickel Catalysts ◽

Temperature Programmed ◽

Co Precipitation

A series of 10 wt% Ni/Al2O3–MO (M = Mg, Ca, Ba) catalyst was prepared by impregnation method for applying in the combined steam and carbon dioxide reforming of methane (CSCRM). In this study, five supported nickel catalysts were impregnated on different supports. All of the supports have been obtained by co–precipitation method and also have been investigated. Several techniques, including N2 physisorption measurements, X–ray powder diffraction (XRD), temperature–programmed reduction using H2 (H2–TPR), and transmission electron microscopy (TEM) were used to investigate catalysts’ physicochemical properties. The results showed that MgO was the most suitable promoter comparing with CaO and BaO in CSCRM. The presence of MgO in Ni/Al2O3 changed catalysts’ characteristics leading to an increase in the catalytic activity and stability with time on stream (TOS). It was found that the suitable catalyst was Ni–based on Al2O3–MgO of mass ratio 2:1 which showed a high metal dispersion as well as dominated spinel structure. The CH4 and CO2 conversion at 800 °C reached 99.8 % and 51.7 %, respectively. Catalytic stability of this catalyst with TOS at 800 °C could reach to more than 20 hours until it started decreasing.

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Effect of the Ni/Al Ratio on the Performance of NiAl2O4 Spinel-Based Catalysts for Supercritical Methylcyclohexane Catalytic Cracking

Catalysts ◽

10.3390/catal11030323 ◽

2021 ◽

Vol 11 (3) ◽

pp. 323

Author(s):

Kyoung Ho Song ◽

Soon Kwan Jeong ◽

Byung Hun Jeong ◽

Kwan-Young Lee ◽

Hak Joo Kim

Keyword(s):

Spinel Structure ◽

Coke Formation ◽

Strong Acid ◽

Acid Sites ◽

The Other ◽

X Ray ◽

Temperature Programmed Oxidation ◽

Temperature Programmed ◽

Co Precipitation ◽

Strong Acid Sites

Supercritical methylcyclohexane cracking of NiAl2O4 spinel-based catalysts with varying Ni/Al deficiencies was investigated. Thus, catalysts with Ni content of 10–50 wt.% were prepared by typical co-precipitation methods. The calcined, reduced, and spent catalysts were characterized by X-ray diffraction, O2 temperature-programmed oxidation, NH3 temperature-programmed desorption, N2 physisorption, O2 chemisorption, scanning and transmission electron microscopy, and X-ray fluorescence. The performance and physicochemical properties of the reference stoichiometric Ni3Al7 catalyst differed significantly from those of the other catalysts. Indeed, the Ni-deficient Ni1Al9 catalyst led to the formation of large Ni particles (diameter: 20 nm) and abundant strong acid sites, without spinel structure formation, owing to the excess Al. These acted with sufficient environment and structure to form the coke precursor nickel carbide, resulting in a pressure drop within 17 min. On the other hand, the additional NiO linked to the NiAl2O4 spinel structure of the Al-deficient Ni5Al5 catalyst formed small crystals (10 nm), owing to the excess Ni, and displayed improved Ni dispersion. Thus, dehydrogenation proceeded effectively, thereby improving the resistance to coke formation. This catalytic behavior further demonstrated the remarkable activity and stability of this catalyst under mild conditions (450 °C and 4 Mpa).

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Characteristics and activity of Ni/CeO2 catalyst modified by Cr2O3 in combined steam and CO2 reforming of CH4

Vietnam Journal of Catalysis and Adsorption ◽

10.51316/jca.2021.017 ◽

2021 ◽

Vol 10 (1) ◽

pp. 104-108

Author(s):

Phuong Phan Hong ◽

Anh Nguyen Phung ◽

Huy Tran Anh ◽

Tri Nguyen ◽

Loc Luu Cam

Keyword(s):

Chemical Properties ◽

Catalytic Performance ◽

Molar Ratio ◽

Impregnation Method ◽

Co2 Reforming ◽

X Ray ◽

Co2 Reforming Of Ch4 ◽

Transmission Electron ◽

Physico Chemical ◽

Temperature Programmed

A series of 10%wtNiO/CeO2-nanorod catalyst without and with Cr2O3 additive was prepared by simultaneous impregnation method. Several techniques, including N2 physisorption measurements, X-ray powder diffraction (XRD), temperature-programmed reduction using H2 (H2-TPR), CO2 temperature-programmed desorption (CO2-TPD), scanning electron microscope (SEM) and transmission electron microscopy (TEM) were used to investigate catalysts’ physico-chemical properties. The activity of the catalysts in combined steam and CO2 reforming of CH4 (BRM) was investigated at temperature range of 550-800 °C. The results showed that 10%NiO0.1%Cr2O3/CeO2 catalyst had the best catalytic performance due to a better reducibility and basicity. At 700 °C and CH4:CO2:H2O molar ratio in feed stream of 3:1.2:2.4, both conversion of CH4 and CO2 on this catalyst reached 98.5%.

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Zeolite Beta Doped with La, Fe, and Pd as a Hydrocarbon Trap

Catalysts ◽

10.3390/catal10020173 ◽

2020 ◽

Vol 10 (2) ◽

pp. 173

Author(s):

Rasmus Jonsson ◽

Jungwon Woo ◽

Magnus Skoglundh ◽

Louise Olsson

Keyword(s):

Photoelectron Spectroscopy ◽

Inductively Coupled Plasma ◽

Zeolite Beta ◽

Substantial Part ◽

Catalyst Characterization ◽

Incipient Wetness Impregnation ◽

X Ray ◽

Temperature Programmed Oxidation ◽

Temperature Programmed

Hydrocarbon trapping is a technique of great relevance, since a substantial part of hydrocarbon emissions from engines are released from engines before the catalyst has reached the temperature for efficient conversion of the hydrocarbons. In this work, the influence of doping zeolite beta (BEA) with Fe, Pd, and La on the storage and release of propene and toluene is studied. Five monolith samples were prepared; Fe/BEA, La/BEA, Pd/BEA, Pd/Fe/BEA, and Pd/La/BEA using incipient wetness impregnation, and the corresponding powder samples were used for catalyst characterization by Inductively coupled plasma sector field mass spectrometry (ICP-SFMS), Temperature-programmed oxidation (TPO), X-ray photoelectron spectroscopy (XPS) and Scanning transmission electron microscopy with Energy dispersive X-ray analysis (STEM-EDX). The hydrocarbon trapping ability of the samples was quantified using Temperature-programmed desorption (TPD) of propene and toluene, and in situ Diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS). The results from the TPD experiments show that the addition of Pd and La to the zeolite affected the release patterns of the stored hydrocarbons on the trapping material in a positive way. The in situ DRIFTS results indicate that these elements provide H-BEA with additional sites for the storage of hydrocarbons. Furthermore, EDX-mapping showed that the La and Pd are located in close connection.

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