scholarly journals Catalytic Performance and Characterization of Ni-Co Bi-Metallic Catalysts in n-Decane Steam Reforming: Effects of Co Addition

Catalysts ◽  
2018 ◽  
Vol 8 (11) ◽  
pp. 518 ◽  
Author(s):  
Qinwei Yu ◽  
Yi Jiao ◽  
Weiqiang Wang ◽  
Yongmei Du ◽  
Chunying Li ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Energy Dispersive Spectrometer ◽  
Coke Deposition ◽  
Morphological Properties ◽  
Temperature Programmed Reduction ◽  
N2 Adsorption ◽  
High Hydrogen ◽  
Hydrogen Selectivity ◽  
Temperature Programmed ◽  
Adsorption Desorption

Co-Ni bi-metallic catalysts supported on Ce-Al2O3 (CA) were prepared with different Co ratios, and the catalytic behaviors were assessed in the n-decane steam reforming reaction with the purpose of obtaining high H2 yield with lower inactivation by carbon deposition. Physicochemical characteristics studies, involving N2 adsorption-desorption, X-ray diffraction (XRD), H2-temperature-programmed reduction (H2-TPR), NH3 temperature programmed reduction (NH3-TPD), SEM-energy dispersive spectrometer (EDS), and transmission electron microscope (TEM)/HRTEM, were performed to reveal the textural, structural and morphological properties of the catalysts. Activity test indicated that the addition of moderate Co can improve the hydrogen selectivity and anti-coking ability compared with the mono-Ni/Ce-Al2O3 contrast catalyst. In addition, 12% Co showed the best catalytic activity in the series Co-Ni/Ce-Al2O3 catalysts. The results of catalysts characterizations of XRD and N2 adsorption-desorption manifesting the metal-support interactions were significantly enhanced, and there was obvious synergistic effect between Ni and Co. Moreover, the introduction of 12% Co and 6% Ni did not exceed the monolayer saturation capacity of the Ce-Al2O3 support. Finally, 6 h stability test for the optimal catalyst 12%Co-Ni/Ce-Al2O3 demonstrated that the catalyst has good long-term stability to provide high hydrogen selectivity, as well as good resistance to coke deposition.

scholarly journals Composites of Laponite and Cu–Mn Hopcalite-Related Mixed Oxides Prepared from Inverse Microemulsions as Catalysts for Total Oxidation of Toluene

Materials ◽  
2018 ◽  
Vol 11 (8) ◽  
pp. 1365 ◽  
Author(s):  
Bogna D. Napruszewska ◽  
Alicja Michalik ◽  
Anna Walczyk ◽  
Dorota Duraczyńska ◽  
Roman Dula ◽  
...  
Keyword(s):  
Mixed Oxide ◽  
Mixed Oxides ◽  
Active Phase ◽  
Temperature Programmed Reduction ◽  
Tetrabutylammonium Hydroxide ◽  
N2 Adsorption ◽  
Total Oxidation ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Mesoporous Structures

Composites of Laponite and Cu–Mn hopcalite-related mixed oxides, prepared from hydrotalcite-like (Htlc) precursors obtained in inverse microemulsions, were synthesized and characterized with XRF, XRD, SEM, TEM, H2 temperature-programmed reduction (TPR), and N2 adsorption/desorption at −196 °C. The Htlc precursors were precipitated either with NaOH or tetrabutylammonium hydroxide (TBAOH). Al was used as an element facilitating Htlc structure formation, and Ce and/or Zr were added as promoters. The composites calcined at 600 °C are mesoporous structures with similar textural characteristics. The copper–manganite spinel phases formed from the TBAOH-precipitated precursors are less crystalline and more susceptible to reduction than the counterparts obtained from the precursors synthesized with NaOH. The Cu–Mn-based composites are active in the combustion of toluene, and their performance improves further upon the addition of promoters in the following order: Ce < Zr < Zr + Ce. The composites whose active phases are prepared with TBAOH are more active than their counterparts obtained with the use of the precursors precipitated with NaOH, due to the better reducibility of the less crystalline mixed oxide active phase.

scholarly journals Ru-Promoted Ni/Al2O3 Fluidized Catalyst for Biomass Gasification

Catalysts ◽  
2020 ◽  
Vol 10 (3) ◽  
pp. 316 ◽  
Author(s):  
Alan Rubén Calzada Hernandez ◽  
Daniel Gibran González Castañeda ◽  
Adriana Sánchez Enriquez ◽  
Hugo de Lasa ◽  
Benito Serrano Rosales
Keyword(s):  
Acid Site ◽  
Biomass Gasification ◽  
Temperature Programmed Desorption ◽  
Steam Gasification ◽  
Bet Surface Area ◽  
Temperature Programmed Reduction ◽  
N2 Adsorption ◽  
Site Density ◽  
Temperature Programmed ◽  
Adsorption Desorption

Fluidizable catalysts based on Ni/Al2O3 with added Ru were used for the gasification of a lignin surrogate (2-methoxy-4-methylphenol) in a fluidized CREC Riser Simulator reactor. This was done in order to quantify lignin surrogate conversion and lignin surrogate products (H2, CO, CO2 and CH4) as well as the coke deposited on the catalyst. The catalysts that were evaluated contained 5% wt. Ni with various Ru loadings (0.25%, 0.5% and 1% wt). These catalysts were synthesized using an incipient Ni and Ru co-impregnation. Catalysts were characterized using XRD, N2 adsorption-desorption (BET Surface Area, BJH), Temperature Programmed Reduction (TPR), Temperature Programmed Desorption (TPD) and H2 chemisorption. Catalytic steam gasification took place at 550, 600 and 650 °C using 0.5, 1.0 and 1.5, steam/biomass ratios. The results obtained showed that Ru addition helped to decrease both nickel crystallite site sizes and catalyst acid site density. Moreover, it was observed that coke on the catalyst was reduced by 60%. This was the case when compared to the runs with the Ni/Al2O3 free of Ru.

Hydrogen Production from Ethanol Steam Reforming Using Ce- and La- Modified Mesoporous MCM-41 Supported Nickel-Based Catalysts

2019 ◽  
Vol 17 (8) ◽  
Author(s):  
Lida Rahmanzadeh ◽  
Majid Taghizadeh
Keyword(s):  
Hydrogen Production ◽  
Steam Reforming ◽  
Fixed Bed ◽  
Fixed Bed Reactor ◽  
Ethanol Conversion ◽  
Steam Reforming Of Ethanol ◽  
Hydrogen Selectivity ◽  
Temperature Programmed ◽  
Adsorption Desorption ◽  
Mcm 41

Abstract Mesoporous MCM-41 containing different amounts of nickel (10, 15 and 20 wt%) and Ce and/or La promoters were prepared by hydrothermal and wet-impregnation methods. The catalysts were characterized by means of temperature-programmed reduction (TPR), X-ray diffraction (XRD), field emission scanning electron microscopy (FE-SEM), N2 adsorption-desorption, Fourier transform infrared (FT-IR) spectroscopy, and thermogravimetric (TGA) analyses. Then, the catalysts were tested for hydrogen production via steam reforming of ethanol in a fixed bed reactor. Hydrogen selectivity and ethanol conversion over Ni/MCM-41 catalyst were 69.6 % and 94 %, respectively. The best catalytic results were obtained with Ce-Ni/MCM-41 catalyst, i. e. 94 % ethanol conversion and 76.5 % hydrogen selectivity. These results remained constant about 90 h time on stream and ethanol conversion decreased to 87 % after 120 h.

Hydrogen Adsorption Capacity Investigation of Ni-Co-Al Mixed Oxides

2014 ◽  
Vol 917 ◽  
pp. 360-364 ◽  
Author(s):  
M. Abdus Salam ◽  
Suriati Sufian
Keyword(s):  
Hydrogen Adsorption ◽  
Mixed Oxides ◽  
Textural Properties ◽  
Metal Dispersion ◽  
Temperature Programmed Reduction ◽  
Oxide Formation ◽  
Nickel Cobalt ◽  
Icp Ms ◽  
Temperature Programmed ◽  
Adsorption Desorption

Micro-mesoporous mixed oxides containing nickel, cobalt and aluminum have been synthesized using conventional coprecipitation method. FESEM and HRTEM analyses demonstrated the flower and hexagonal plate-like nanostructured of mixed oxides. Different mixed oxide formation, homogenous metal dispersion, textural properties were investigated using XRD, ICP-MS and BET (N2 adsorption-desorption) techniques. nanostructured mixed oxides exhibited 2.6 wt% hydrogen adsorption that were studied using temperature programmed reduction-adsorption-desorption (H2-TPR/TPD) and thermogravimetric and differential thermal analysis (TGA-DTA) techniques. Investigation corresponds that morphologies, textural properties and surface energy of mixed oxides are important in hydrogen adsorption.

scholarly journals Sustainable Production of Hydrogen by Steam Reforming of Ethanol Using Cobalt Supported on Nanoporous Zeolitic Material

Nanomaterials ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 1934
Author(s):  
Javier Francisco da Costa-Serra ◽  
Maria Teresa Navarro ◽  
Fernando Rey ◽  
Antonio Chica
Keyword(s):  
Steam Reforming ◽  
Zeolite Y ◽  
Cobalt Catalysts ◽  
Coke Deposition ◽  
Bet Surface Area ◽  
Ethanol Conversion ◽  
Y Zeolite ◽  
Steam Reforming Of Ethanol ◽  
Production Of Hydrogen ◽  
Hydrogen Selectivity

Cobalt catalysts supported on Y zeolite and mesoporized Y zeolite (Y-mod) have been studied in steam reforming of ethanol (SRE). Specifically, the effect of the mesoporosity and the acidity of the y zeolite as a support has been explored. Mesoporous were generated on Y zeolite by treatment with NH4F and the acidity was neutralized by Na incorporation. Four cobalt catalysts supported on Y zeolite have been prepared, two using Y zeolite without mesoporous (Co/Y, Co/Y-Na), and two using Y zeolite with mesoporous (Co/Y-mod and Co/Y-mod-Na). All catalysts showed a high activity, with ethanol conversion values close to 100%. The main differences were found in the distribution of the reaction products. Co/Y and Co/Y-mod catalysts showed high selectivity to ethylene and low hydrogen production, which was explained by their high acidity. On the contrary, neutralization of the acid sites could explain the higher hydrogen selectivity and the lower ethylene yields exhibited by the Co/Y-Na and Co/Y-mod-Na. In addition, the physicochemical characterization of these catalysts by XRD, BET surface area, temperature-programmed reduction (TPR), and TEM allowed to connect the presence of mesoporous with the formation of metallic cobalt particles with small size, high dispersion, and with high interaction with the zeolitic support, explaining the high reforming activity exhibited by the co/y-mod-Na sample as well as its higher hydrogen selectivity. It has been also observed that the formation of coke is affected by the presence of mesoporous and acidity. Both properties seem to have an opposite effect on the reforming catalyst, decreasing and increasing the coke deposition, respectively.

scholarly journals Nickel Supported on AlCeO3 as a Highly Selective and Stable Catalyst for Hydrogen Production via the Glycerol Steam Reforming Reaction

Catalysts ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 411 ◽  
Author(s):  
Nikolaos D. Charisiou ◽  
Georgios I. Siakavelas ◽  
Binlin Dou ◽  
Victor Sebastian ◽  
Steven J. Hinder ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Steam Reforming ◽  
Photoelectron Spectroscopy ◽  
Liquid Product ◽  
Coke Deposition ◽  
Tem Analysis ◽  
X Ray ◽  
Surface Basicity ◽  
Ce Modification ◽  
Temperature Programmed

In this study, a critical comparison between two low metal (Ni) loading catalysts is presented, namely Ni/Al2O3 and Ni/AlCeO3 for the glycerol steam reforming (GSR) reaction. The surface and bulk properties of the catalysts were evaluated using a plethora of techniques, such as N2 adsorption/desorption, Inductively Coupled Plasma Atomic Emission Spectroscopy (ICP–AES), X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), Scanning Electron Microscopy / Energy Dispersive X-Ray Spectroscopy (SEM/EDX, Transmission Electron Microscopy (TEM), CO2 and NH3– Temperature Programmed Desorption (TPD), and Temperature Programmed Reduction (H2–TPR). Carbon deposited on the catalyst’s surfaces was probed using Temperature Programmed Oxidation (TPO), SEM, and TEM. It is demonstrated that Ce-modification of Al2O3 induces an increase of the surface basicity and Ni dispersion. These features lead to a higher conversion of glycerol to gaseous products (60% to 80%), particularly H2 and CO2, enhancement of WGS reaction, and a higher resistance to coke deposition. Allyl alcohol was found to be the main liquid product for the Ni/AlCeO3 catalyst, the production of which ceases over 700 °C. It is also highly significant that the Ni/AlCeO3 catalyst demonstrated stable values for H2 yield (2.9–2.3) and selectivity (89–81%), in addition to CO2 (75–67%) and CO (23–29%) selectivity during a (20 h) long time-on-stream study. Following the reaction, SEM/EDX and TEM analysis showed heavy coke deposition over the Ni/Al2O3 catalyst, whereas for the Ni/AlCeO3 catalyst TPO studies showed the formation of more defective coke, the latter being more easily oxidized.

Promotion Effects of La2O3 on Ni/Al2O3 Catalysts for CO2 Methanation

2015 ◽  
Vol 1118 ◽  
pp. 205-210 ◽  
Author(s):  
Wei Chang Chen ◽  
Wen Yang ◽  
Jian Dong Xing ◽  
Lei Liu ◽  
Hong Li Sun ◽  
...  
Keyword(s):  
Particle Size ◽  
Impregnation Method ◽  
Temperature Programmed Reduction ◽  
Active Components ◽  
X Ray ◽  
Induce Effect ◽  
Temperature Programmed ◽  
Ni Species ◽  
Adsorption Desorption ◽  
Catalytic Performances

Ni/Al2O3catalysts improved with different La contents were prepared by the conventional co-impregnation method and characterized by X-ray powder diffraction (XRD), N2adsorption-desorption, H2temperature-programmed reduction (H2-TPR). Catalytic performances for CO2methanation under condition (CO2/H2=4.1:1, 1 atm) were discussed in detail. XRD result demonstrated that the addition of La was in favor of decreasing the Ni particle size and increasing the dispersion of Ni species. The H2-TPR showed that La can change the proportion of various Ni species and increase the content of easily reducible Ni species. These results indicate that La species induce effect, resulting in smaller particle size and weaker interaction between active components and the support, higher dispersions, and reducibility of active phases, ultimately improving catalytic activity of CO2methanation.

scholarly journals High Active and Selective Ni/CeO2–Al2O3 and Pd–Ni/CeO2–Al2O3 Catalysts for Oxy-Steam Reforming of Methanol

Catalysts ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 380 ◽  
Author(s):  
Pawel Mierczynski ◽  
Agnieszka Mierczynska ◽  
Radoslaw Ciesielski ◽  
Magdalena Mosinska ◽  
Magdalena Nowosielska ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Photoelectron Spectroscopy ◽  
Supported Catalysts ◽  
Energy Dispersive Spectrometer ◽  
Nickel Catalysts ◽  
Impregnation Method ◽  
Catalytic Systems ◽  
X Ray ◽  
Steam Reforming Of Methanol ◽  
Temperature Programmed

Herein, we report monometallic Ni and bimetallic Pd–Ni catalysts supported on CeO2–Al2O3 binary oxide which are highly active and selective in oxy-steam reforming of methanol (OSRM). Monometallic and bimetallic supported catalysts were prepared by an impregnation method. The physicochemical properties of the catalytic systems were investigated using a range of methods such as: Brunauer–Emmett–Teller (BET), X-ray Powder Diffraction (XRD), Temperature-programmed reduction (TPR–H2), Temperature-programmed desorption (TPD–NH3), X-ray photoelectron spectroscopy (XPS) and Scanning Electron Microscope equipped with an energy dispersive spectrometer (SEM–EDS). We demonstrate that the addition of palladium facilitates the reduction of nickel catalysts. The activity tests performed for all catalysts confirmed the promotion effect of palladium on the catalytic activity of nickel catalyst and their selectivity towards hydrogen production. Both nickel and bimetallic palladium–nickel supported catalysts showed excellent stability during the reaction. The reported catalytic systems are valuable to make advances in the field of fuel cell technology.

Study of Preparation, Characterization and Temperature-Programmed Reduction of NiO-ZnO Binary Materials

2013 ◽  
Vol 664 ◽  
pp. 515-520
Author(s):  
Chih Wei Tang ◽  
Jiunn Jer Hwang ◽  
Shie Hsiung Lin ◽  
Chin Chun Chung
Keyword(s):  
Weight Percent ◽  
Precipitation Method ◽  
Temperature Programmed Reduction ◽  
X Ray Diffraction ◽  
X Ray ◽  
Surface Areas ◽  
Temperature Programmed ◽  
Co Precipitation ◽  
Adsorption Desorption

The NiO-ZnO binary materials had been prepared by co-precipitation method. The weight percent of nickel of NiO-ZnO materials were 5, 10 and 20; they were pretreated under air at temperature of 300, 500 and 700°C, respectively. The characterization of NiO-ZnO materials were the thermal gravity analysis(TGA), X-ray diffraction(XRD), N2 adsorption-desorption at 77K, scaning electron microscope(SEM) and temperature-programmed reduction(TPR). The results revealed that surface areas of NiO-ZnO materials order from large to small were 20NiZn(OH)x(66 m2·g-1) > 10NiZn(OH)x(34 m2·g-1) > 5NiZn(OH)x(9 m2·g-1) after being calcined at the temperature of 500°C. Further, NiO-ZnO materials had two main reductive peaks at 390-415°C and 560-657°C, respectively. In all NiO-ZnO materials, 20NiZn(OH)x-C500 material had the highest surface area and the best interaction between NiO and ZnO.

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