4 research outputs found
Rational design of bimetallic nanoparticles based catalysts : application for apgrading biomass
L'accumulation de crises sociales, Ă©conomiques et Ă©nergĂ©tiques depuis des dĂ©cennies conduit la sociĂ©tĂ© Ă une situation critique. La dĂ©pendance aux combustibles fossiles pour la production d'Ă©nergie et de produits chimiques doit ĂŞtre rapidement rĂ©duite en remplaçant les sources fossiles par des sources renouvelables. La biomasse lignocellulosique apparaĂ®t comme une bonne alternative pour la production de produits chimiques et de carburants durables. Cette matière première renouvelable, composĂ©e de cellulose, d'hĂ©micelluloses et de lignine, se trouve en grande partie dans les dĂ©chets, le bois, les cultures Ă©nergĂ©tiques et les rĂ©sidus agricoles. Les matières premières de deuxième gĂ©nĂ©ration issues de la biomasse-permettent la production de carburants liquides chimiquement identiques Ă ceux issus du pĂ©trole et utilisables dans les moteurs Ă combustion d'aujourd'hui. Utiliser la biomasse pour la production de produits chimiques est donc une voie prometteuse et d'un grand intĂ©rĂŞt pour l'environnement. Plusieurs molĂ©cules plateformes, telles que le furfural et le 5-hydroxymĂ©thylfurfural, sont accessibles Ă partir de la biomasse, pouvant conduire Ă une vaste gamme de composĂ©s Ă valeur ajoutĂ©e. Pour rĂ©aliser ces transformations de façon performante, des nanocatalyseurs bimĂ©talliques Ă base de mĂ©taux abondants ont Ă©tĂ© dĂ©veloppĂ©s, en pensant Ă leur incorporation potentielle dans des processus industriels pour la transition Ă©nergĂ©tique. Une sĂ©rie de matĂ©riaux bimĂ©talliques associant le Ru au Ni ou au Cu comme second mĂ©tal a Ă©tĂ© synthĂ©tisĂ©e avec succès et entièrement caractĂ©risĂ©e. DiffĂ©rents stabilisants ont Ă©tĂ© utilisĂ©s, tels que la polyvinylpyrrolidone, la diphĂ©nyl-2-pyridylphosphine et l'hexadĂ©cylamine, conduisant Ă des nanomatĂ©riaux bimĂ©talliques RuNi et RuCu bien contrĂ´lĂ©s et de très petite taille (<2nm), avec diffĂ©rents ratios en mĂ©taux. Des homologues monomĂ©talliques ont aussi Ă©tĂ© prĂ©parĂ©s Ă des fins de comparaison. Les nanoparticules RuNi/PVP ont montrĂ© des effets synergiques entre les mĂ©taux dans l'hydrogĂ©nation catalytique efficace et sĂ©lective du furfural et du 5-hydroxymĂ©thylfurfural. Des calculs DFT par modĂ©lisation des nanoparticules de Ru, Ni et RuNiavec adsorption de diverses espèces Ă leur surface ont permis de mieux comprendre les rĂ©sultats expĂ©rimentaux. Les rĂ©sultats obtenus confirment l'activitĂ© et la sĂ©lectivitĂ© observĂ©es en catalyse. Lorsqu'utilisĂ©es comme catalyseurs dans la mĂŞme rĂ©action d'hydrogĂ©nation, les nanoparticules de RuCu/PVP sont moins performantes que les homologues monomĂ©talliques correspondants et que les nanoparticules RuNi/PVP. Les nanoparticules RuNi/PVP et RuNi/PPh2Py ont Ă©galement catalysĂ© l'hydrogĂ©nation sĂ©lective de la quinolĂ©ine, en observant une dĂ©pendance de l'activitĂ© par rapport Ă la tempĂ©rature et la teneur en Ru. En utilisant le 1-propanol comme solvant, la N-alkylation du substrat s'est produite de façon notable Ă partir de 125ÂşC. Le deutĂ©rium Ă©tant un isotope stable et sĂ»r de l'hydrogène, les molĂ©cules marquĂ©es au deutĂ©rium suscitent un grand intĂ©rĂŞt, notamment dans l'industrie mĂ©dicinale et pharmaceutique pour la conception de nouveaux mĂ©dicaments. Les nanoparticules Ru/PVP ont Ă©tĂ© testĂ©es pour la deutĂ©ration d'une sĂ©rie de substrats modèles (4-mĂ©thoxyaniline, 4-trifluoromĂ©thylbenzaldĂ©hyde, mĂ©thyl-2,3-O-Isopropylidène-β-D-ribofuranoside et adĂ©nosine). MalgrĂ© l'absence dedeutĂ©ration, des rĂ©actions intĂ©ressantes de dĂ©protection et d'Ă©pimĂ©risation ont Ă©tĂ© observĂ©es pour les trois premiers substrats. Avec l'adĂ©nosine, la deutĂ©ration a eu lieu de manière sĂ©lective. Ce travail dĂ©crit la synthèse de nouveaux nanomatĂ©riaux bimĂ©talliques prĂ©sentant des propriĂ©tĂ©s modulables et prometteuses pour la catalyse. L'hydrogĂ©nation de molĂ©cules dĂ©rivĂ©es de la biomasse, telles que le furfural et le 5-hydroxymĂ©thylfurfural, a Ă©tĂ© menĂ©e avec succès. Des nanoparticules monomĂ©talliques de Ru/PVP ont Ă©galement permis de catalyser des rĂ©actions de deutĂ©ration.An accumulation of social, economic, and energetic crises occurring for decades drives the society to a critical situation. The dependency on fossil fuels for energy and chemicals production is noticeable and needs to be rapidly reduced by replacing those sources with renewable ones. Lignocellulosic biomass appears as a good alternative to the production of sustainable chemicals and fuels. This renewable feedstock is composed of cellulose, hemicelluloses and lignin, and can be vastly found in waste streams, wood, energy crops and agricultural residues. Liquid fuels may be produced from second generation feedstocks of biomass, which are chemically identical to the ones from petroleum, and which can be used in the same combustion engines as those present nowadays. The replacement of fossil by biomass feedstocks for the production of chemicals is of great interest for environmental purposes. This promising feedstock can produce several platform molecules, such as furfural and 5-hydroxymethylfurfural, from which a vast range of value-added compounds can be obtained. For a better performance of these transformations, selective and effective bimetallic nanocatalysts have been developed in this work, containing earth-abundant metals, thinking about their potential incorporation in industrial processes for energy transition. For this purpose, a series of Ru bimetallic materials containing either Ni or Cu as second metal were synthesised. Several stabilisers for the nanoparticles were used such as polyvinylpyrrolidone, diphenyl-2-pyridylphosphine and hexadecylamine. The synthesis of ultra-small (<2nm) RuCu and RuNi bimetallic nanomaterials, as well as their monometallic counterparts, was successful, by controlling the metal ratio between metals. RuNi/PVP nanoparticles showed synergetic effects between metals in both efficient and selective catalytic hydrogenations of furfural and 5-hydroxymethylfurfural. DFT calculations were performed to help us understand the experimental results, by modelling Ru, Ni and RuNi nanoparticles and adsorbing the different species on their surface. The results from theoretical calculations are in the line of the activity and selectivity observed in experimental catalytic experiments. RuCu/PVP nanoparticles, used as catalysts in the same hydrogenation reaction, were less performant than the corresponding monometallic counterparts, as well as the RuNi/PVP nanoparticles. RuNi/PVP and RuNi/PPh2Py nanoparticles were used as catalysts on the selective hydrogenation of quinoline, observing a dependence of the activity on the temperature and the Ru content. By using 1-propanol as solvent, N-alkylation of the substrat occurred, noticeably from 125ÂşC. Deuterium-labelled molecules, being a stable and safe hydrogen isotope, have received great interest in different scientific domains, especially in pharmaceutical industry for the design of new drugs. Ru/PVP nanoparticles were tested for deuteration reactions of 4-methoxyaniline, 4-trifluoromethylbenzaldehyde, methyl-2,3-O-Isopropylidene-beta-D-ribofuranoside and adenosine. Deuterations were not successful in the two first substrates nor in the third, where, nevertheless, deprotection and epimerisation reactions were observed. In the case of adenosine, the deuteration took place in a selective manner. This work offers the synthesis of new bimetallic nanomaterials with tunable properties. Some of the developed catalysts were tested in the hydrogenation of platform molecules, such as furfural and 5-hydroxymethylfurfural, and the monometallic Ru/PVP nanoparticles were used as catalysts in deuteration reactions
Conception rationnelle de catalyseurs à base de nanoparticules bimétalliques : application à la valorisation de la biomasse
An accumulation of social, economic, and energetic crises occurring for decades drives the society to a critical situation. The dependency on fossil fuels for energy and chemicals production is noticeable and needs to be rapidly reduced by replacing those sources with renewable ones. Lignocellulosic biomass appears as a good alternative to the production of sustainable chemicals and fuels. This renewable feedstock is composed of cellulose, hemicelluloses and lignin, and can be vastly found in waste streams, wood, energy crops and agricultural residues. Liquid fuels may be produced from second generation feedstocks of biomass, which are chemically identical to the ones from petroleum, and which can be used in the same combustion engines as those present nowadays. The replacement of fossil by biomass feedstocks for the production of chemicals is of great interest for environmental purposes. This promising feedstock can produce several platform molecules, such as furfural and 5-hydroxymethylfurfural, from which a vast range of value-added compounds can be obtained. For a better performance of these transformations, selective and effective bimetallic nanocatalysts have been developed in this work, containing earth-abundant metals, thinking about their potential incorporation in industrial processes for energy transition. For this purpose, a series of Ru bimetallic materials containing either Ni or Cu as second metal were synthesised. Several stabilisers for the nanoparticles were used such as polyvinylpyrrolidone, diphenyl-2-pyridylphosphine and hexadecylamine. The synthesis of ultra-small (<2nm) RuCu and RuNi bimetallic nanomaterials, as well as their monometallic counterparts, was successful, by controlling the metal ratio between metals. RuNi/PVP nanoparticles showed synergetic effects between metals in both efficient and selective catalytic hydrogenations of furfural and 5-hydroxymethylfurfural. DFT calculations were performed to help us understand the experimental results, by modelling Ru, Ni and RuNi nanoparticles and adsorbing the different species on their surface. The results from theoretical calculations are in the line of the activity and selectivity observed in experimental catalytic experiments. RuCu/PVP nanoparticles, used as catalysts in the same hydrogenation reaction, were less performant than the corresponding monometallic counterparts, as well as the RuNi/PVP nanoparticles. RuNi/PVP and RuNi/PPh2Py nanoparticles were used as catalysts on the selective hydrogenation of quinoline, observing a dependence of the activity on the temperature and the Ru content. By using 1-propanol as solvent, N-alkylation of the substrat occurred, noticeably from 125ÂşC. Deuterium-labelled molecules, being a stable and safe hydrogen isotope, have received great interest in different scientific domains, especially in pharmaceutical industry for the design of new drugs. Ru/PVP nanoparticles were tested for deuteration reactions of 4-methoxyaniline, 4-trifluoromethylbenzaldehyde, methyl-2,3-O-Isopropylidene-beta-D-ribofuranoside and adenosine. Deuterations were not successful in the two first substrates nor in the third, where, nevertheless, deprotection and epimerisation reactions were observed. In the case of adenosine, the deuteration took place in a selective manner. This work offers the synthesis of new bimetallic nanomaterials with tunable properties. Some of the developed catalysts were tested in the hydrogenation of platform molecules, such as furfural and 5-hydroxymethylfurfural, and the monometallic Ru/PVP nanoparticles were used as catalysts in deuteration reactions.L'accumulation de crises sociales, Ă©conomiques et Ă©nergĂ©tiques depuis des dĂ©cennies conduit la sociĂ©tĂ© Ă une situation critique. La dĂ©pendance aux combustibles fossiles pour la production d'Ă©nergie et de produits chimiques doit ĂŞtre rapidement rĂ©duite en remplaçant les sources fossiles par des sources renouvelables. La biomasse lignocellulosique apparaĂ®t comme une bonne alternative pour la production de produits chimiques et de carburants durables. Cette matière première renouvelable, composĂ©e de cellulose, d'hĂ©micelluloses et de lignine, se trouve en grande partie dans les dĂ©chets, le bois, les cultures Ă©nergĂ©tiques et les rĂ©sidus agricoles. Les matières premières de deuxième gĂ©nĂ©ration issues de la biomasse-permettent la production de carburants liquides chimiquement identiques Ă ceux issus du pĂ©trole et utilisables dans les moteurs Ă combustion d'aujourd'hui. Utiliser la biomasse pour la production de produits chimiques est donc une voie prometteuse et d'un grand intĂ©rĂŞt pour l'environnement. Plusieurs molĂ©cules plateformes, telles que le furfural et le 5-hydroxymĂ©thylfurfural, sont accessibles Ă partir de la biomasse, pouvant conduire Ă une vaste gamme de composĂ©s Ă valeur ajoutĂ©e. Pour rĂ©aliser ces transformations de façon performante, des nanocatalyseurs bimĂ©talliques Ă base de mĂ©taux abondants ont Ă©tĂ© dĂ©veloppĂ©s, en pensant Ă leur incorporation potentielle dans des processus industriels pour la transition Ă©nergĂ©tique. Une sĂ©rie de matĂ©riaux bimĂ©talliques associant le Ru au Ni ou au Cu comme second mĂ©tal a Ă©tĂ© synthĂ©tisĂ©e avec succès et entièrement caractĂ©risĂ©e. DiffĂ©rents stabilisants ont Ă©tĂ© utilisĂ©s, tels que la polyvinylpyrrolidone, la diphĂ©nyl-2-pyridylphosphine et l'hexadĂ©cylamine, conduisant Ă des nanomatĂ©riaux bimĂ©talliques RuNi et RuCu bien contrĂ´lĂ©s et de très petite taille (<2nm), avec diffĂ©rents ratios en mĂ©taux. Des homologues monomĂ©talliques ont aussi Ă©tĂ© prĂ©parĂ©s Ă des fins de comparaison. Les nanoparticules RuNi/PVP ont montrĂ© des effets synergiques entre les mĂ©taux dans l'hydrogĂ©nation catalytique efficace et sĂ©lective du furfural et du 5-hydroxymĂ©thylfurfural. Des calculs DFT par modĂ©lisation des nanoparticules de Ru, Ni et RuNiavec adsorption de diverses espèces Ă leur surface ont permis de mieux comprendre les rĂ©sultats expĂ©rimentaux. Les rĂ©sultats obtenus confirment l'activitĂ© et la sĂ©lectivitĂ© observĂ©es en catalyse. Lorsqu'utilisĂ©es comme catalyseurs dans la mĂŞme rĂ©action d'hydrogĂ©nation, les nanoparticules de RuCu/PVP sont moins performantes que les homologues monomĂ©talliques correspondants et que les nanoparticules RuNi/PVP. Les nanoparticules RuNi/PVP et RuNi/PPh2Py ont Ă©galement catalysĂ© l'hydrogĂ©nation sĂ©lective de la quinolĂ©ine, en observant une dĂ©pendance de l'activitĂ© par rapport Ă la tempĂ©rature et la teneur en Ru. En utilisant le 1-propanol comme solvant, la N-alkylation du substrat s'est produite de façon notable Ă partir de 125ÂşC. Le deutĂ©rium Ă©tant un isotope stable et sĂ»r de l'hydrogène, les molĂ©cules marquĂ©es au deutĂ©rium suscitent un grand intĂ©rĂŞt, notamment dans l'industrie mĂ©dicinale et pharmaceutique pour la conception de nouveaux mĂ©dicaments. Les nanoparticules Ru/PVP ont Ă©tĂ© testĂ©es pour la deutĂ©ration d'une sĂ©rie de substrats modèles (4-mĂ©thoxyaniline, 4-trifluoromĂ©thylbenzaldĂ©hyde, mĂ©thyl-2,3-O-Isopropylidène-β-D-ribofuranoside et adĂ©nosine). MalgrĂ© l'absence dedeutĂ©ration, des rĂ©actions intĂ©ressantes de dĂ©protection et d'Ă©pimĂ©risation ont Ă©tĂ© observĂ©es pour les trois premiers substrats. Avec l'adĂ©nosine, la deutĂ©ration a eu lieu de manière sĂ©lective. Ce travail dĂ©crit la synthèse de nouveaux nanomatĂ©riaux bimĂ©talliques prĂ©sentant des propriĂ©tĂ©s modulables et prometteuses pour la catalyse. L'hydrogĂ©nation de molĂ©cules dĂ©rivĂ©es de la biomasse, telles que le furfural et le 5-hydroxymĂ©thylfurfural, a Ă©tĂ© menĂ©e avec succès. Des nanoparticules monomĂ©talliques de Ru/PVP ont Ă©galement permis de catalyser des rĂ©actions de deutĂ©ration
In Situ Ruthenium Catalyst Modification for the Conversion of Furfural to 1,2-Pentanediol
International audienceExploiting biomass to synthesise compounds that may replace fossil-based ones is of high interest in order to reduce dependence on non-renewable resources. 1,2-pentanediol and 1,5-pentanediol can be produced from furfural, furfuryl alcohol or tetrahydrofurfuryl alcohol following a metal catalysed hydrogenation/C-O cleavage procedure. Colloidal ruthenium nanoparticles stabilized with polyvinylpyrrolidone in situ modified with different organic compounds are able to produce 1,2-pentanediol directly from furfural in a 36% of selectivity at 125 °C under 20 bar of H2 pressure
Bimetallic RuNi nanoparticles as catalysts for upgrading biomass: metal dilution and solvent effects on selectivity shifts
RuNi nanoparticles (NP) were prepared by decomposition of [Ru(η4-C8H12)(η6-C8H10)] and [Ni(η4-C8H12)2] by H2 in the presence of polyvinylpyrrolidone (PVP) at 85 °C using several Ru/Ni ratios. The nanoparticles display a segregated structure in which Ni is on the surface, as ascertained by wide angle X-ray scattering (WAXS). The catalytic activity in the selective hydrogenation of furfural of these RuNi NP was correlated with the Ru content. High selectivity towards the partially hydrogenated product 2-(hydroxymethyl)furan (HF) was found when carrying out the reaction in tetrahydrofuran (THF). A different scenario was found when using a protic polar solvent, 1-propanol. Catalysts displaying Ru on the surface were able to hydrogenate the heteroaromatic ring, while those with Ni on the surface were highly selective towards the partially hydrogenated product. In addition, Ru surfaces were prone to catalyse the acetalization reaction in the presence of the alcoholic solvent, while the addition of Ni supressed this reactivity. Density functional theory (DFT) calculations performed on hydrogenated Ru nanoparticles (Ru55H70) show differences in the adsorption energies of several reagents, products, reaction intermediates, and solvents onto the Ru NP surface, which are in line with the experimental catalytic results