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Huge plastic consumption and depletion of fossil fuels are at the top of the world's envi-ronmental and energy challenges. The scientific community has tackled these issues through differ-ent approaches. Catalytic pyrolysis of plastic wastes to valuable products has been proved as a sustainable route which fits with the circular economy aspects. The design of catalytic materials is the central factor for performing the catalytic conversion of plastic wastes. This review aims to conduct a Bibliometric analysis of the pyrolysis of plastic wastes and non-precious-based catalysts by mapping research studies over the last fifty years. The analysis was developed via VOSviewer and RStudio tools. It showed the historical progress regarding plastic waste pyrolysis to produce valu-able products and chemicals worldwide. The research shows that the top five countries with the highest citations and publications in this field were Spain, China, England, the USA and India. The Journal of Analytical and Applied Pyrolysis had the most comprehensive coverage of plastic waste. The relationship between the catalyst and the mechanism of plastic waste can influence the production yield and selectivity. The research gap and underrepresented research topics were iden-tified, and previous research studies on developing non-precious-based catalysts that were most rel-evant to the current topic were reviewed and discussed. The challenges and perspectives on catalyst preparation and development for material complexity were critically discussed. Challenges of pre-vious studies and directions for future research were provided. This report might guide the reader to take a general look at plastic waste valorization by pyrolysis and easily understand the main chal-lenges. (c) 2023 The Author(s). Publis

In this work bimetallic Ni catalysts supported over Co-Al2O3 and monometallic Co-Al2O3 and Ni-Al2O3 catalysts were examined for the complete oxidation of methane. With a 30 % total metallic loading, the samples were synthesized by a sequential precipitation route. All samples were characterized by nitrogen physisorption, X-ray fluorescence, X-ray diffraction, Raman spectroscopy, scanning electron microscopy, scanning-transmission electron microscopy, X-Ray photoelectron spectroscopy, and temperature-programmed reduction with hydrogen and methane. Their catalytic performance was investigated in the temperature range of 200-600 degrees C with a space velocity of 60.000 h-1. The bimetallic catalysts showed a better behavior in the oxidation reaction than the monometallic counterparts, mainly due to the good dispersion of Ni on the surface of the Co-Al2O3 samples. This has enabled the insertion of Ni2+ ions into the cobalt spinel lattice, which in turn provoked an increase in the amount of Co3+ species, and a subsequent enhanced mobility of oxygen species in the spinel. In this sense, the 5Ni/25Co catalyst showed the best performance, thus reducing the value of the T50 by 25 degrees C with respect to the monometallic catalysts.

A series of novel ONO ligands bearing an ionic pendant-armed (hereinafter indicated as ONONu, where Nu corresponds to an anionic nucleophile) were synthesized, characterized, and successfully coordinated to cobalt and manganese precursors. New air-stable cobalt (III) complexes (1-6) and manganese (II) complexes (7 and 8) were obtained and characterized. Single crystal X-ray diffraction analysis of the Co(III) compound 5 confirmed the presence of two quaternized ligands coordinated to the metal and iodide as counterion. These novel complexes were revealed to be active catalysts in the coupling reaction of carbon dioxide and propylene oxide (PO) in different degrees of success. Among these, the manganese complex 8 afforded the best results towards the formation of propylene carbonate (PC) with a productivity of 256 kg PC/(kg cat center dot h), achieving a TON of 4860.

This work describes the possible application of cyclic voltammetry (CV) for obtaining information about cobalt phases onto alumina supported cobalt catalysts.Starting from the same amount of ingredients, two catalysts with different phases of cobalt were prepared: Co3O4-A obtained by manual grinding of Co3O4 and alumina in an agate mortar and CoAl2O4-A obtained mechanochemically using a planetary ball mill.The final productswere characterized by the temperature-programmed reduction (TPR) and CV. The TPR profile of Co3O4-A showed peaks between 200–500°C characteristic of Co3O4 reduction, while the profile of CoAl2O4-A was altered in the whole temperature region and especially by the appearance of new peaks in the region of temperatures of 600–900oC.This result indicated that a certain amount ofhard-to-reduce cobalt aluminate is generated during milling. CVin alkaline solution revealed that theoxidation/reduction of cobalt in CoAl2O4-Aoccurred at more negative potentials compared with cobalt in Co3O4-A.Negative shift of peak potential well correlated with the appearance of high-temperature TPR peak and could be ascribed to the cobalt phase which has lower tendency to get reduced. These findings encourage the idea of using the CV as low cost and rapid assay for distinguishing the cobalt phases onto alumina.

This work describes the possible application of cyclic voltammetry (CV) for obtaining information about cobalt phases onto alumina supported cobalt catalysts.Starting from the same amount of ingredients, two catalysts with different phases of cobalt were prepared: Co3O4-A obtained by manual grinding of Co3O4 and alumina in an agate mortar and CoAl2O4-A obtained mechanochemically using a planetary ball mill.The final productswere characterized by the temperature-programmed reduction (TPR) and CV. The TPR profile of Co3O4-A showed peaks between 200–500°C characteristic of Co3O4 reduction, while the profile of CoAl2O4-A was altered in the whole temperature region and especially by the appearance of new peaks in the region of temperatures of 600–900oC.This result indicated that a certain amount ofhard-to-reduce cobalt aluminate is generated during milling. CVin alkaline solution revealed that theoxidation/reduction of cobalt in CoAl2O4-Aoccurred at more negative potentials compared with cobalt in Co3O4-A.Negative shift of peak potential well correlated with the appearance of high-temperature TPR peak and could be ascribed to the cobalt phase which has lower tendency to get reduced. These findings encourage the idea of using the CV as low cost and rapid assay for distinguishing the cobalt phases onto alumina.

[EN] This paper focuses on the development of active and stable catalysts for the steam reforming of alcoholic wastes. Two catalysts with high activity in the steam reforming of ethanol have been studied in the steam reforming of an alcoholic waste from the vinery industry, as previous step to their industrial scale up. The catalysts are based on cobalt supported on Zn-hydrotalcite-derived material and natural sepiolite. At laboratory level, the catalytic material based on natural sepiolite showed the best catalytic performance maintaining its catalytic activity for more than 160 h in presence of 50 ppm of sulfur contained in the alcoholic waste. Thus, sepiolite based catalyst was scaled up to prepare a first generation of catalytic monoliths. The reforming activity of this first generation of monoliths was found lower than their corresponding powdered catalyst. The high calcination temperature (1573 K) used in the manufacture of the first generation of monoliths was the responsible of their low performance, which was related to the sintering of cobalt catalyst in a larger crystallite size of metallic cobalt. A second generation of monoliths was prepared using a lower calcination temperature (873 K). Now, the monoliths exhibited a high catalytic performance, similar to the powdered catalyst. The excellent results obtained with the second generation of monoliths have been protected under an invention patent (E201731077). This is the first time that catalytic monoliths based on natural sepiolite promoted with Co are successfully manufactured and tested in the steam reforming of alcoholic wastes from the distillery industry to produce hydrogen.

[EN] This paper focuses on the development of active and stable catalysts for the steam reforming of alcoholic wastes. Two catalysts with high activity in the steam reforming of ethanol have been studied in the steam reforming of an alcoholic waste from the vinery industry, as previous step to their industrial scale up. The catalysts are based on cobalt supported on Zn-hydrotalcite-derived material and natural sepiolite. At laboratory level, the catalytic material based on natural sepiolite showed the best catalytic performance maintaining its catalytic activity for more than 160 h in presence of 50 ppm of sulfur contained in the alcoholic waste. Thus, sepiolite based catalyst was scaled up to prepare a first generation of catalytic monoliths. The reforming activity of this first generation of monoliths was found lower than their corresponding powdered catalyst. The high calcination temperature (1573 K) used in the manufacture of the first generation of monoliths was the responsible of their low performance, which was related to the sintering of cobalt catalyst in a larger crystallite size of metallic cobalt. A second generation of monoliths was prepared using a lower calcination temperature (873 K). Now, the monoliths exhibited a high catalytic performance, similar to the powdered catalyst. The excellent results obtained with the second generation of monoliths have been protected under an invention patent (E201731077). This is the first time that catalytic monoliths based on natural sepiolite promoted with Co are successfully manufactured and tested in the steam reforming of alcoholic wastes from the distillery industry to produce hydrogen.

Disordered materials with resilient and soft-templated functional units bear the potential to fill the pipeline of robust catalysts for renewable energy storage. However, for novel materials lacking long-range order, the ability to discern local structure with atomic resolution still pushes the boundaries of current analytical and modeling approaches. We introduce a two-pillar strategy to monitor the formation and unravel the structure of the first disordered onedimensional cobalt coordination polymer catalyst, Co-dppeO2. This target material excels through proven high performance in commercial alkaline electrolyzers and organic transformations. We demonstrate that the key architecture behind this activity is the unconventional embedding of hydrated {H2O-Co2(OH)2-OH2} edge-site motifs, nested into a flexible organic matrix of highly oxidized and bridging hydrophobic dppeO2 ligands. Our combination of in situ spectroscopy and computational modeling of X-ray scattering and absorption spectra, backed with complementary experimental techniques, holds the key to understanding the atomic-range structure of important disordered materials.

Disordered materials with resilient and soft-templated functional units bear the potential to fill the pipeline of robust catalysts for renewable energy storage. However, for novel materials lacking long-range order, the ability to discern local structure with atomic resolution still pushes the boundaries of current analytical and modeling approaches. We introduce a two-pillar strategy to monitor the formation and unravel the structure of the first disordered onedimensional cobalt coordination polymer catalyst, Co-dppeO2. This target material excels through proven high performance in commercial alkaline electrolyzers and organic transformations. We demonstrate that the key architecture behind this activity is the unconventional embedding of hydrated {H2O-Co2(OH)2-OH2} edge-site motifs, nested into a flexible organic matrix of highly oxidized and bridging hydrophobic dppeO2 ligands. Our combination of in situ spectroscopy and computational modeling of X-ray scattering and absorption spectra, backed with complementary experimental techniques, holds the key to understanding the atomic-range structure of important disordered materials.

Disordered materials with resilient and soft-templated functional units bear the potential to fill the pipeline of robust catalysts for renewable energy storage. However, for novel materials lacking long-range order, the ability to discern local structure with atomic resolution still pushes the boundaries of current analytical and modeling approaches. We introduce a two-pillar strategy to monitor the formation and unravel the structure of the first disordered onedimensional cobalt coordination polymer catalyst, Co-dppeO2. This target material excels through proven high performance in commercial alkaline electrolyzers and organic transformations. We demonstrate that the key architecture behind this activity is the unconventional embedding of hydrated {H2O-Co2(OH)2-OH2} edge-site motifs, nested into a flexible organic matrix of highly oxidized and bridging hydrophobic dppeO2 ligands. Our combination of in situ spectroscopy and computational modeling of X-ray scattering and absorption spectra, backed with complementary experimental techniques, holds the key to understanding the atomic-range structure of important disordered materials.

Partial oxidation of methane (POM) was studied over a series of Co/Mg-Al catalysts. Various commercial hydroxides with different Mg/Al ratios were used as precursors of the oxides employed as catalytic supports, as well as MgO prepared in the laboratory. The effects of Co loading, Mg content, and calcination temperature (400–750¿°C) were studied on the POM reaction. The catalytic performance was evaluated at 800¿°C in a fixed-bed tubular quartz reactor under a high space velocity of 300¿L N CH4/(gcat¿h) and a O2/CH4 molar ratio of 0.5. A very high activity was obtained during 4¿h on-stream with a 20¿wt. % Co catalyst prepared with a Mg-Al mixed oxide support having a MgO content of 63¿wt. %. This catalyst gave CH4 conversions (91.3%) very close to the maximum corresponding to the thermodynamic equilibrium. Such notable performance could be attained with the catalyst precursor subjected to calcination at 500¿°C for 6¿h and subsequent in situ reduction under H2 flow at 800¿°C for 2¿h. Two main types of deactivation mechanisms were generally observed in most of the samples that suffered either a very rapid cobalt re-oxidation upon their exposure to the POM reaction atmosphere or significant deposition of carbonaceous deposits of different kinds. The characterization of the spent samples by transmission electron microscopy (TEM) revealed the presence of carbon deposits of different nature in the Mg/Al samples having a high MgO content, including filamentous carbon (whiskers), onion-shell like sheets and/or amorphous encapsulating layers. Conversely, no carbon deposits were observed in the spent Co/MgO catalyst, which underwent oxidation of the relatively less dispersed surface Co sites to form clearly defined crystals of Co oxides with particle diameters typically ranging between 25 and 100¿nm., Peer Reviewed, Postprint (author's final draft)

Structure and catalytic performance of niobia-supported cobalt catalysts were studied based on crystal phase, porosity and cobalt loading. Crystalline niobia as support proved to be a prerequisite to obtain highly active and selective Co/niobia Fischer–Tropsch catalysts, whereas amorphous niobia showed minimal activity. Crystallization changed the porous morphology of Nb2O5·nH2O resulting in a dense material with low specific pore volume and specific surface area. Multiple impregnations on crystalline Nb2O5were necessary to achieve cobalt loadings higher than 6 wt.%; this led to larger cobalt particles, diminished interaction of cobalt with niobia and therefore decreased activity per unit weight of cobalt and C5+selectivity. Carbon deposition via sucrose pyrolysis was employed in order to partly maintain the porosity during crystallization. The obtained porous crystalline niobia was used as support for cobalt catalysts with higher metal loadings. STEM-EDX mapping characterization of the catalysts provided unique information for this kind of materials, e.g. cobalt distribution and particle size. The catalysts showed high cobalt-normalized catalytic activity and C5+selectivity for the Fischer–Tropsch synthesis under industrially relevant conditions. Moreover, higher cobalt loadings led to an increased catalyst-weight normalized catalytic activity.

The catalytic hydrogenations of CO and CO2 to more useful chemicals is not only beneficial in producing more valuable products and reducing dependence on fossil fuels, but present a scientific challenge in how to control the selectivity of these reactions. Using colloidal chemistry techniques, a high level of control over the synthesis of nanomaterials can be achieved, and by exploiting this fact a simple model system can be realized to understand the reaction of CO and CO2 on a molecular level. Specifically, this dissertation focuses on understanding cobalt materials for the conversion of CO and CO2 into more useful, valuable chemicals.Colloidally prepared cobalt nanoparticles with a narrow size distribution were supported in mesoporous SiO2 and TiO2 to study the effect of the support on the Co catalyzed hydrogenation of CO and CO2. The 10nm Co/SiO2 and Co/TiO2 catalysts were tested for CO and CO2 hydrogenation at 5 bar with a ratio to hydrogen of 1:2 and 1:3, respectively. In addition, the effect of Co oxidation state was studied by using different reduction pretreatment temperatures (250°C and 450°C). The results showed that for both hydrogenation reactions, Co/TiO2 had a high activity at both reduction temperatures compared to Co/SiO2. However, unlike Co/SiO2 which showed higher activity after 450°C reduction, Co/TiO2 had a higher activity after reduction at 250°C. Through synchrotron x-ray spectroscopy, it was concluded that the TiO2 was wetting the Co particle at higher reduction temperatures and dewetting at lower reduction temperatures. In addition to the wetting, CoO was observed to be the surface species on Co/TiO2 catalyst after reduction at low temperatures, which catalyzed both CO and CO2 hydrogenation reactions with higher activity than the Co metal obtained after reduction at 450°C.Classical steady-state measurements are limited in so much as they are often unable to provide information on individual reaction steps in complex reaction pathways. To att

The catalytic hydrogenations of CO and CO2 to more useful chemicals is not only beneficial in producing more valuable products and reducing dependence on fossil fuels, but present a scientific challenge in how to control the selectivity of these reactions. Using colloidal chemistry techniques, a high level of control over the synthesis of nanomaterials can be achieved, and by exploiting this fact a simple model system can be realized to understand the reaction of CO and CO2 on a molecular level. Specifically, this dissertation focuses on understanding cobalt materials for the conversion of CO and CO2 into more useful, valuable chemicals.Colloidally prepared cobalt nanoparticles with a narrow size distribution were supported in mesoporous SiO2 and TiO2 to study the effect of the support on the Co catalyzed hydrogenation of CO and CO2. The 10nm Co/SiO2 and Co/TiO2 catalysts were tested for CO and CO2 hydrogenation at 5 bar with a ratio to hydrogen of 1:2 and 1:3, respectively. In addition, the effect of Co oxidation state was studied by using different reduction pretreatment temperatures (250°C and 450°C). The results showed that for both hydrogenation reactions, Co/TiO2 had a high activity at both reduction temperatures compared to Co/SiO2. However, unlike Co/SiO2 which showed higher activity after 450°C reduction, Co/TiO2 had a higher activity after reduction at 250°C. Through synchrotron x-ray spectroscopy, it was concluded that the TiO2 was wetting the Co particle at higher reduction temperatures and dewetting at lower reduction temperatures. In addition to the wetting, CoO was observed to be the surface species on Co/TiO2 catalyst after reduction at low temperatures, which catalyzed both CO and CO2 hydrogenation reactions with higher activity than the Co metal obtained after reduction at 450°C.Classical steady-state measurements are limited in so much as they are often unable to provide information on individual reaction steps in complex reaction pathways. To att

[EN] Steam reforming of ethanol was investigated between 400 degrees C and 600 degrees C over 3 mol% Y2O3 doped ZrO2 monolith infiltrated with Co, known as an effective catalyst for this reaction. Monoliths were fabricated by implementing the freeze-casting technique in order to obtain hierarchical, vertical and highly ordered porous microstructure resulting in very low pressure drop, high surface area and accessibility to active sites. Catalytic monoliths were firstly loaded with 3 wt% of Co. Catalytic activity of Co-containing monolith was compared with the catalytic activity of a powdered material with the same chemical composition than the catalytic monolith. The results show a clear improvement all over the temperature range of the ethanol conversion and H-2 yield and a decrease of the by-products contents when using a freeze-cast monolith support. The incorporation of La enabled a strong decrease in coke deposition over the activated monolith. The effect of the addition of 0.25 wt.% of Pt was also studied. Pt makes possible to inhibit carbon deposition but has a detrimental effect on ethanol conversion at temperatures above 500 degrees C and on H-2 selectivity at low temperature. A higher Pt loading of 0.8 wt% did not bring any beneficial effect and was even detrimental at low temperature. Finally, the beneficial effect of the implementation of freeze-cast monolith in comparison with the not structured fixed-bed configuration is explained by the difference of packing since and improved fluid dynamics at similar GHSV, the former one promotes in a higher proportion the Water Gas Shift Reaction (WGSR) further in the monolith length. (C) 2017 Elsevier B.V. All rights reserved.

Two cobalt catalysts, Co/SBA-15 and Co/SiO, have been studied in steam reforming of ethanol (SRE). Besides the steam reforming products, ethoxide dehydrogenation to acetaldehyde is observed as one of the main reactions. Although by hydrogen treatment cobalt is reduced to the metallic state, under SRE conditions, a phase appears that has been identified as cobalt carbide and correlates with acetaldehyde production. These findings provide insights about the catalytic sites, for SRE, in cobalt catalysts. Comparison with previous results shows that these conclusions are not translatable to other cobalt catalysts, stressing the importance of the support on the catalytic behavior of cobalt. (Chemical Equation Presented).

[EN] Steam reforming of ethanol was investigated between 400 degrees C and 600 degrees C over 3 mol% Y2O3 doped ZrO2 monolith infiltrated with Co, known as an effective catalyst for this reaction. Monoliths were fabricated by implementing the freeze-casting technique in order to obtain hierarchical, vertical and highly ordered porous microstructure resulting in very low pressure drop, high surface area and accessibility to active sites. Catalytic monoliths were firstly loaded with 3 wt% of Co. Catalytic activity of Co-containing monolith was compared with the catalytic activity of a powdered material with the same chemical composition than the catalytic monolith. The results show a clear improvement all over the temperature range of the ethanol conversion and H-2 yield and a decrease of the by-products contents when using a freeze-cast monolith support. The incorporation of La enabled a strong decrease in coke deposition over the activated monolith. The effect of the addition of 0.25 wt.% of Pt was also studied. Pt makes possible to inhibit carbon deposition but has a detrimental effect on ethanol conversion at temperatures above 500 degrees C and on H-2 selectivity at low temperature. A higher Pt loading of 0.8 wt% did not bring any beneficial effect and was even detrimental at low temperature. Finally, the beneficial effect of the implementation of freeze-cast monolith in comparison with the not structured fixed-bed configuration is explained by the difference of packing since and improved fluid dynamics at similar GHSV, the former one promotes in a higher proportion the Water Gas Shift Reaction (WGSR) further in the monolith length. (C) 2017 Elsevier B.V. All rights reserved.

Cobalt hydrotalcite-derived catalysts, doped with potassium, are active materials for the ethanol steam reforming reaction. Potassium addition reduces the acid sites number and strength. It acts as a promoter of the ethanol steam reforming (ESR); ethanol conversion is higher at lower temperature, as the amount of potassium at the surface of the catalyst increases. The catalysts are stable for long-term experiments (300 h) under high loads of ethanol and bioethanol (0.036 gEtOH min−1, H2O:CH3CH2OH = 4:1 molar). Moreover, they generate a low amount of carbon (0.0067 gC gcatalyst−1 h−1). The catalysts after reaction contain almost exclusively high spin Co2+ in cobalt oxide (or in (Co,Mg)O); only traces of metallic cobalt are identified by magnetometry, <0.1 wt.% Co0, suggesting that oxidized cobalt is an active species in ESR., Postprint (published version)

During this PhD thesis, cobalt (Co) catalysts have been prepared, characterized and studied in the carbon monoxide hydrogenation (CO+H2) reaction (also known as “Fischer-Tropsch” (FT) reaction). In industry, the FT synthesis aims at producing long chain hydrocarbons such as gasoline or diesel fuels. The interest is that the reactants (CO and H2) are obtained from other carbonaceous sources than crude oil: natural gas, coal, biomass or even petroleum residues. As it is well known that the worldwide crude oil reserves will be depleted in a few decades, the FT reaction represents an attractive alternative for the production of various fuels. Moreover, this reaction can also be used to produce high value specialty chemicals (long chain alcohols, light olefins…).Two different types of catalysts have been investigated during this thesis: cobalt with magnesia used as support or dispersant (Co/MgO) and cobalt with silica used as support (Co/SiO2). Each catalyst from the first class is prepared by precipitation of a mixed Co/Mg oxalate in acetone. This coprecipitation is followed by a thermal decomposition under reductive atmosphere leading to a mixed Co/MgO catalyst. On the other hand, Co/SiO2 catalysts are prepared by impregnation of a commercial silica support with a chloroform solution containing Co nanoparticles. This impregnation is then followed by a thermal activation under reductive atmosphere.The mixed Co/Mg oxalates and the resulting Co/MgO catalysts have been extensively characterized in order to gain a better understanding of the composition, the structure and the morphology of these materials: thermal treatments under reductive and inert atmospheres (followed by MS, DRIFTS, TGA and DTA), BET surface area measurements, XRD and electron microscopy studies have been performed. Moreover, an original in situ technique for measuring the H2 chemisorption surface area of catalysts has been developed and used over our catalysts.The performances of the Co/MgO an, Doctorat en Sciences de l'ingénieur, info:eu-repo/semantics/nonPublished

During this PhD thesis, cobalt (Co) catalysts have been prepared, characterized and studied in the carbon monoxide hydrogenation (CO+H2) reaction (also known as “Fischer-Tropsch” (FT) reaction). In industry, the FT synthesis aims at producing long chain hydrocarbons such as gasoline or diesel fuels. The interest is that the reactants (CO and H2) are obtained from other carbonaceous sources than crude oil: natural gas, coal, biomass or even petroleum residues. As it is well known that the worldwide crude oil reserves will be depleted in a few decades, the FT reaction represents an attractive alternative for the production of various fuels. Moreover, this reaction can also be used to produce high value specialty chemicals (long chain alcohols, light olefins…).Two different types of catalysts have been investigated during this thesis: cobalt with magnesia used as support or dispersant (Co/MgO) and cobalt with silica used as support (Co/SiO2). Each catalyst from the first class is prepared by precipitation of a mixed Co/Mg oxalate in acetone. This coprecipitation is followed by a thermal decomposition under reductive atmosphere leading to a mixed Co/MgO catalyst. On the other hand, Co/SiO2 catalysts are prepared by impregnation of a commercial silica support with a chloroform solution containing Co nanoparticles. This impregnation is then followed by a thermal activation under reductive atmosphere.The mixed Co/Mg oxalates and the resulting Co/MgO catalysts have been extensively characterized in order to gain a better understanding of the composition, the structure and the morphology of these materials: thermal treatments under reductive and inert atmospheres (followed by MS, DRIFTS, TGA and DTA), BET surface area measurements, XRD and electron microscopy studies have been performed. Moreover, an original in situ technique for measuring the H2 chemisorption surface area of catalysts has been developed and used over our catalysts.The performances of the Co/MgO an, Doctorat en Sciences de l'ingénieur, info:eu-repo/semantics/nonPublished