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.

scholarly journals Heterogeneous Fenton-like oxidation of p-hydroxybenzoic acid using Fe/CeO2-TiO2 catalyst

2019 ◽  
Vol 79 (7) ◽  
pp. 1276-1286 ◽  
Author(s):  
Tijani Hammedi ◽  
Mohamed Triki ◽  
Mayra G. Alvarez ◽  
Jordi Llorca ◽  
Abdelhamid Ghorbel ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Catalytic Properties ◽  
Molar Ratio ◽  
Hydroxybenzoic Acid ◽  
X Ray ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
Temperature Programmed

Abstract This paper is built on the Fenton-like oxidation of p-hydroxybenzoic acid (p–HBZ) in the presence of H2O2 and 3%Fe supported on CeO2-TiO2 aerogels under mild conditions. These catalysts were deeply characterized by X-ray diffraction (XRD), hydrogen temperature programmed reduction (H2-TPR), transmission electron microscopy (TEM), scanning transmission electron microscopy (STEM) and X-ray photoelectron spectroscopy (XPS). The effect of thermal treatment, pH (2–3, 5, 7), H2O2/p–HBZ molar ratio (5, 15, 20, 25) and reaction temperature (25 °C, 40 °C and 60 °C) on the catalytic properties of supported Fe catalysts are studied. Our results highlight the role of CeO2 and the calcination of the catalyst to obtain the highest catalytic properties after 10 min: 73% of p–HBZ conversion and 52% of total organic carbon (TOC) abatement.

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.

scholarly journals Effect of Time on a Hierarchical Corn Skeleton-Like Composite of CoO@ZnO as Capacitive Electrode Material for High Specific Performance Supercapacitors

Energies ◽  
2018 ◽  
Vol 11 (12) ◽  
pp. 3285 ◽  
Author(s):  
Yedluri Kumar ◽  
Hee-Je Kim
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
High Performance ◽  
Xrd Analysis ◽  
Cycling Performance ◽  
Energy Storage Devices ◽  
Tem Analysis ◽  
X Ray ◽  
Potential Applications ◽  
Oxygen Groups

CoO–ZnO-based composites have attracted considerable attention for the development of energy storage devices because of their multifunctional characterization and ease of integration with existing components. This paper reports the synthesis of CoO@ZnO (CZ) nanostructures on Ni foam by the chemical bath deposition (CBD) method for facile and eco-friendly supercapacitor applications. The formation of a CoO@ZnO electrode functioned with cobalt, zinc, nickel and oxygen groups was confirmed by X-ray diffraction (XRD) analysis, X-ray photoelectron spectroscopy (XPS), low and high-resolution scanning electron microscopy (SEM), and transmission electron microscopy (TEM) analysis. The as-synthesized hierarchical nanocorn skeleton-like structure of a CoO@ZnO-3h (CZ3h) electrode delivered a higher specific capacitance (Cs) of 1136 F/g at 3 A/g with outstanding cycling performance, showing 98.3% capacitance retention over 3000 cycles in an aqueous 2 M KOH electrolyte solution. This retention was significantly better than that of other prepared electrodes, such as CoO, ZnO, CoO@ZnO-1h (CZ1h), and CoO@ZnO-7h (CZ7h) (274 F/g, 383 F/g, 240 F/g and 537 F/g). This outstanding performance was attributed to the excellent surface morphology of CZ3h, which is responsible for the rapid electron/ion transfer between the electrolyte and the electrode surface area. The enhanced features of the CZ3h electrode highlight potential applications in high performance supercapacitors, solar cells, photocatalysis, and electrocatalysis.

scholarly journals Zinc Oxide Nanoparticles from Waste Zn-C Battery via Thermal Route: Characterization and Properties

Nanomaterials ◽  
2018 ◽  
Vol 8 (9) ◽  
pp. 717 ◽  
Author(s):  
Rifat Farzana ◽  
Ravindra Rajarao ◽  
Pravas Behera ◽  
Kamrul Hassan ◽  
Veena Sahajwalla
Keyword(s):  
Electron Microscopy ◽  
Zno Nanoparticles ◽  
Photoelectron Spectroscopy ◽  
Uv Light ◽  
Inert Atmosphere ◽  
Bet Surface Area ◽  
Visible Range ◽  
Tem Analysis ◽  
Thermal Synthesis ◽  
X Ray

Disposable batteries are becoming the primary sources of powering day-to-day gadgets and consequently contributing to e-waste generation. The emerging e-waste worldwide is creating concern regarding environmental and health issues. Therefore, a sustainable recycling approach of spent batteries has become a critical focus. This study reports the detail characterization and properties of ZnO nanoparticles recovered from spent Zn-C batteries via a facile thermal synthesis route. ZnO nanoparticles are used in many applications including energy storage, gas sensors, optoelectronics, etc. due to the exceptional physical and optical properties. A thermal treatment at 900 °C under an inert atmosphere of argon was applied to synthesize ZnO nanoparticles from a spent Zn-C battery using a horizontal quartz tube furnace. X-ray diffraction (XRD), selected area electron diffraction (SAED) and X-ray photoelectron spectroscopy (XPS) results confirmed the formation of crystalline ZnO nanoparticles. Field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) analysis confirmed that the size of synthesised ZnO particles were less than 50 nm and mainly composed of sphere shaped nanoparticles. Synthesized ZnO exhibited BET surface area of 9.2629 m2/g and showed absorption of light in the UV region. Excitation of ZnO by UV light showed photoluminescence in the visible range. This study will create an opportunity for potential applications of ZnO nanoparticles from spent batteries and will benefit the environment by reducing the volume of e-waste in landfills.

scholarly journals Propane and Naphthalene Oxidation over Gold-Promoted Cobalt Catalysts Supported on Zirconia

Catalysts ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 387
Author(s):  
María Silvia Leguizamón Aparicio ◽  
María Lucia Ruiz ◽  
Marco Antonio Ocsachoque ◽  
Marta Isabel Ponzi ◽  
Enrique Rodríguez-Castellón ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Photoelectron Spectroscopy ◽  
Cobalt Catalysts ◽  
Bet Surface Area ◽  
Promoting Effect ◽  
Propane Combustion ◽  
X Ray ◽  
Transmission Electron ◽  
Temperature Programmed ◽  
Supported Gold

Zirconia-supported gold-promoted cobalt catalysts were synthesized and tested for the complete oxidation of propane and naphthalene. The catalysts were characterized by BET surface area, scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), powder X-ray diffraction (XRD), transmission electron microscopy (TEM), temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS). In both propane and naphthalene combustion reactions, the results obtained indicate that catalysts formulated with Co3O4 are more active than those containing only Au. Catalysts prepared using the deposit/precipitation (DP) method have better activity than those in which the traditional technique is used. Gold addition using the DP methods generates a promoting effect on the activity of cobalt-containing catalysts. The AuDpCoZt catalyst was found to be the most active for both propane and naphthalene combustion. The catalytic behavior of this sample is associated with a synergic effect between gold, cobalt, and the support, which is also evidenced by an increase in the reducibility of this catalytic system. The effect of the presence of NO in the feed was also analyzed for propane combustion.

Fabrication of Mn-FeOx/CNTs Catalysts for Low-Temperature NO Reduction with NH3

NANO ◽  
2015 ◽  
Vol 10 (04) ◽  
pp. 1550050 ◽  
Author(s):  
Yanbing Zhang ◽  
Zhe Xu ◽  
Xie Wang ◽  
Xiulian Lu ◽  
Yuying Zheng
Keyword(s):  
Electron Microscopy ◽  
Low Temperature ◽  
Metal Oxides ◽  
Photoelectron Spectroscopy ◽  
Catalytic Reduction ◽  
Amorphous Structure ◽  
X Ray ◽  
Temperature Programmed ◽  
Xrd Patterns ◽  
Low Temperature Scr

Mn - FeO x/carbon nanotubes (CNTs) catalysts were firstly prepared via simple incipient wetness method and used for low-temperature selective catalytic reduction (SCR) of NO with NH 3. The structure and surface properties of the catalysts were characterized by N 2 sorption, X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), high-resolution transmission electron microscopy (HRTEM), X-ray photoelectron spectroscopy (XPS) and temperature-programmed reduction by hydrogen ( H 2-TPR). It was found that Mn - FeO x/CNTs catalyst exhibited excellent low-temperature SCR activity and SO 2 resistance. XRD patterns revealed that metal oxides catalysts were possessed of amorphous structure. FESEM and TEM images showed that metal oxides catalysts were successfully supported on CNTs. The XPS results indicated that the obtained catalyst presented high Mn 4+/ Mn 3+ and OS/(OS + OL) ratios. The H 2-TPR profiles showed that Mn - FeO x/CNTs catalyst possessed better low-temperature reducibility. Besides, the obtained catalyst exhibited better SO 2 resistance.

scholarly journals Heterogeneous catalytic ozonation of hydroquinone using sewage sludge-derived carbonaceous catalysts

2018 ◽  
Vol 77 (5) ◽  
pp. 1410-1417 ◽  
Author(s):  
Jinglu Xu ◽  
Yang Yu ◽  
Kang Ding ◽  
Zhiying Liu ◽  
Lei Wang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Sewage Sludge ◽  
Photoelectron Spectroscopy ◽  
Removal Rate ◽  
Gas Chromatography Mass Spectrometry ◽  
X Ray Diffraction ◽  
X Ray ◽  
Heterogeneous Catalytic ◽  
Transmission Electron ◽  
Temperature Programmed

Abstract This study converted sewage sludge into a carbonaceous catalyst via pyrolysis and employed it in the ozonation of hydroquinone. The catalyst was characterized by Mössbauer spectroscopy, X-ray photoelectron spectroscopy, temperature programmed desorption, scanning electron microscopy, transmission electron microscopy, Fourier transform infrared spectroscopy and X-ray diffraction. Intermediate products were detected by gas chromatography–mass spectrometry, and a pathway for hydroquinone degradation was proposed. The results showed that sludge pyrolyzed at 700 °C promoted hydroquinone degradation, compared with commercial activated carbon derived from coal. When the catalyst dose was 0.5 g/L, the hydroquinone (200 mg/L) removal rate reached 97.86% after exposure to ozone (the ozone concentration was 17 mg/L and the flow rate was 50 mL/min) for 60 min. The results indicated that basic groups contributed to the catalysis.

scholarly journals Silver decorated CeO2 nanoparticles for rapid photocatalytic degradation of textile rose bengal dye

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
G. Murugadoss ◽  
D. Dinesh Kumar ◽  
M. Rajesh Kumar ◽  
N. Venkatesh ◽  
P. Sakthivel
Keyword(s):  
Electron Microscopy ◽  
Rose Bengal ◽  
Photoelectron Spectroscopy ◽  
Degradation Mechanism ◽  
Tem Analysis ◽  
Visible Absorption ◽  
Paramagnetic Resonance ◽  
X Ray ◽  
Infrared Spectrometer ◽  
Rose Bengal Dye

AbstractHigh quality silver (Ag) decorated CeO2 nanoparticles were prepared by a facile one-step chemical method. The samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), High resolution transmission electron microscopy (HR-TEM), fourier transform infrared spectrometer (FT-IR), electron paramagnetic resonance (EPR), X-ray photoelectron spectroscopy (XPS), UV–Visible absorption (UV–Vis), photoluminescence (PL) and thermogravimetric analysis. The decoration of Ag on CeO2 surface was confirmed by XRD, EPR and HR-TEM analysis. Harmful textile pollutant Rose Bengal dye was degraded under sunlight using the novel Ag decorated CeO2 catalyst. It was found that great enhancement of the degradation efficiency for Ag/CeO2 compared to pure CeO2, it can be ascribed mainly due to decrease in its band gap and charge carrier recombination rate. The Ag/CeO2 sample exhibited an efficient photocatalytic characteristic for degrading RB under visible light irradiation with a high degradation rate of 96% after 3 h. With the help of various characterizations, a possible degradation mechanism has been proposed which shows the effect of generation of oxygen vacancies owing to the decoration of Ag on the CeO2 surface.

scholarly journals The Effect of Noble Metal (M: Ir, Pt, Pd) on M/Ce2O3-γ-Al2O3 Catalysts for Hydrogen Production via the Steam Reforming of Glycerol

Catalysts ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 790
Author(s):  
Nikolaos D. Charisiou ◽  
Georgios I. Siakavelas ◽  
Kyriakos N. Papageridis ◽  
Davide Motta ◽  
Nikolaos Dimitratos ◽  
...  
Keyword(s):  
Steam Reforming ◽  
Photoelectron Spectroscopy ◽  
Acid Sites ◽  
Unsaturated Hydrocarbon ◽  
Effect Of Temperature ◽  
Incipient Wetness Impregnation ◽  
X Ray ◽  
Gaseous Products ◽  
Metal Support Interaction ◽  
Temperature Programmed

A promising route for the energetic valorisation of the main by-product of the biodiesel industry is the steam reforming of glycerol, as it can theoretically produce seven moles of H2 for every mole of C3H8O3. In the work presented herein, CeO2–Al2O3 was used as supporting material for Ir, Pd and Pt catalysts, which were prepared using the incipient wetness impregnation technique and characterized by employing N2 adsorption–desorption, X-Ray Diffraction (XRD), Temperature Programmed Reduction (TPR), Temperature Programmed Desorption (TPD), X-ray Photoelectron Spectroscopy (XPS) and Transmission Electron Microscopy (TEM). The catalytic experiments aimed at identifying the effect of temperature on the total conversion of glycerol, on the conversion of glycerol to gaseous products, the selectivity towards the gaseous products (H2, CO2, CO, CH4) and the determination of the H2/CO and CO/CO2 molar ratios. The main liquid effluents produced during the reaction were quantified. The results revealed that the Pt/CeAl catalyst was more selective towards H2, which can be related to its increased number of Brønsted acid sites, which improved the hydrogenolysis and dehydrogenation–dehydration of condensable intermediates. The time-on-stream experiments, undertaken at low Water Glycerol Feed Ratios (WGFR), showed gradual deactivation for all catalysts. This is likely due to the dehydration reaction, which leads to the formation of unsaturated hydrocarbon species and eventually to carbon deposition. The weak metal–support interaction shown for the Ir/CeAl catalyst also led to pronounced sintering of the metallic particles.

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