Oxidation of glycerol with H2O2 on Pb-promoted Pd/γ-Al2O3 catalysts

A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt% and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at atmospheric pressure, 45℃ and pH=11. The morphology and dispersion of the catalysts were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and transmission electron microscopy (TEM). The presence of an alloy phase in the bimetallic catalyst was detected by X-ray photoelectron spectroscopy (XPS). Glycerol conversion obtained with the monometallic Pd catalyst was 19%, which was increased to 100% with the addition of Pb. The four bimetallic PdPb catalysts were able to oxidize glycerol to dihydroxyacetone (DIHA) and the selectivity to DIHA reached 59%, 58%, 34% and 25% for PdPb0.25, PdPb0.50, PdPb1.00 and PdPb1.60 catalysts, respectively.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ingenierí

Preparación de carbones sulfonados y su utilización en la eterificación de glicerol con alcohol bencílico

Los catalizadores a base de carbón se presentan como una alternativa para la reacción de eterificación de glicerol, ya que pueden ser preparados a partir de precursores de bajo costo, resultan estables en condiciones de reacción no oxidantes, y ofrecen la posibilidad de ser funcionalizados y recuperados para su reutilización En el presente trabajo se estudió la obtención de materiales carbonosos (Cst: con “template" y Csc: carbonización directa) funcionalizados con diferentes grupos sulfónicos (–SO3H y -PhSO3H) para emplearlos como catalizadores heterogéneos en la reacción de eterificación de glicerol (Gly) con alcohol bencílico (BA). Los resultados obtenidos fueron comparados con el desempeño catalítico (conversión y selectividad) de un carbón comercial (Cc), sulfonado en las mismas condiciones. A todos los sistemas ensayados (con y sin tratamiento de funcionalización) se les realizó el análisis superficial, microscopía SEM-EDAX y se les determinó la concentración de sitios ácidos. Para estudiar la estabilidad, se evaluó la reutilización de dichos materiales manteniendo las condiciones de reacción. El método de carbonización con template de sílicato resultó el más adecuado para conseguir un material carbonoso con características superficiales apropiadas para su posterior sulfonación (Cst-SO3H y Cst-PhSO3H). Con estos sistemas se consiguieron buenos resultados de conversión de BA (próximos al 100%) y de selectividad hacia dos de los productos de interés (mayor al 85% para la suma del mono y diéter). Además, estos catalizadores mostraron un desempeño aceptable luego de tres ciclos consecutivos de reacción. Sin embargo, la conversión obtenida fue menor ciclo tras ciclo, producto del bloqueo y lixiviado de los sitios ácidosFil: Chiosso, M. Eugenia. Universidad Nacional del Noroeste de la Provincia de Buenos Aires.Fil: Faroppa, M. Laura. Universidad Nacional del Noroeste de la Provincia de Buenos Aires.Fil: Casella, Mónica L.. Universidad Nacional del Noroeste de la Provincia de Buenos Aires.Fil: Merlo, Andrea B.. Universidad Nacional del Noroeste de la Provincia de Buenos Aires

Oxidación de glicerol sobre catalizadores de platino soportados en carbón y modificados por bismuto

En el presente trabajo se estudian catalizadores de Pt y PtBi soportados sobre carbón para la reacción de oxidación de glicerol (GLY) en fase líquida. El objetivo de este proceso es obtener selectivamente productos de alto valor agregado a partir del glicerol. Se optimizaron las condiciones de reacción las cuales resultaron ser: temperatura 60ºC,un pH de 5, una cantidad de H2O2 para obtener una concentración de 10v de O2, 100 mg de catalizador y relación molar GLY/Pt de 400. Luego de 4 h de reacción el catalizador Pt/C alcanzó una conversión de GLY de 37% con una selectividad de 57% a ácido glicérico. Se estudió el efecto de la concentración de Bi variando la relación Pt:Bi. Se observó que la relación óptima entre ambos metales fue Bi/Pt 0.5 (PtBi0.50/C). Dicho catalizador presentó una selectividad a dihidroxiacetona de un 84.5% para una conversión de 43%.In the present work carbon-supported Pt and PtBi catalysts were studied in the liquid-phase glicerol (GLY) oxidation reaction. The aim of this process is selectively obtain products of high added value from glycerol. The optimum reaction conditions were: temperature 60°C, pH = 5, H2O2 concentration so as to obtain 10vol % O2, 100 mg of catalyst and a GLY/Pt molar ratio of 400. After 4 h of reaction the Pt/C catalyst achieved a GLY conversion of 37% with a selectivity to glyceric acid of 57%. The effect of the Bi concentration was studied by varying the Pt:Bi atomic ratio. It was observed that the optimum ratio between both metals was Bi/Pt = 0.5 (PtBi0.50/C). This catalyst showed a selectivity to dihydroxyacetone of 84.5% for a GLY conversion of 43%.Trabajo publicado en Álvarez, María E., Sandra G. Casuscelli, Mónica E. Crivello y Griselda A. Eimer (eds.). Actas del XX Congreso Argentino de Catálisis. Universidad Tecnológica Nacional, Facultad Regional Córdoba, Buenos Aires, 2017.Facultad de Ciencias Exacta

Oxidación de glicerol sobre catalizadores de platino soportados en carbón y modificados por bismuto

En el presente trabajo se estudian catalizadores de Pt y PtBi soportados sobre carbón para la reacción de oxidación de glicerol (GLY) en fase líquida. El objetivo de este proceso es obtener selectivamente productos de alto valor agregado a partir del glicerol. Se optimizaron las condiciones de reacción las cuales resultaron ser: temperatura 60ºC,un pH de 5, una cantidad de H2O2 para obtener una concentración de 10v de O2, 100 mg de catalizador y relación molar GLY/Pt de 400. Luego de 4 h de reacción el catalizador Pt/C alcanzó una conversión de GLY de 37% con una selectividad de 57% a ácido glicérico. Se estudió el efecto de la concentración de Bi variando la relación Pt:Bi. Se observó que la relación óptima entre ambos metales fue Bi/Pt 0.5 (PtBi0.50/C). Dicho catalizador presentó una selectividad a dihidroxiacetona de un 84.5% para una conversión de 43%.In the present work carbon-supported Pt and PtBi catalysts were studied in the liquid-phase glicerol (GLY) oxidation reaction. The aim of this process is selectively obtain products of high added value from glycerol. The optimum reaction conditions were: temperature 60°C, pH = 5, H2O2 concentration so as to obtain 10vol % O2, 100 mg of catalyst and a GLY/Pt molar ratio of 400. After 4 h of reaction the Pt/C catalyst achieved a GLY conversion of 37% with a selectivity to glyceric acid of 57%. The effect of the Bi concentration was studied by varying the Pt:Bi atomic ratio. It was observed that the optimum ratio between both metals was Bi/Pt = 0.5 (PtBi0.50/C). This catalyst showed a selectivity to dihydroxyacetone of 84.5% for a GLY conversion of 43%.Trabajo publicado en Álvarez, María E., Sandra G. Casuscelli, Mónica E. Crivello y Griselda A. Eimer (eds.). Actas del XX Congreso Argentino de Catálisis. Universidad Tecnológica Nacional, Facultad Regional Córdoba, Buenos Aires, 2017.Facultad de Ciencias Exacta

Oxidación de glicerol sobre catalizadores de platino soportados en carbón y modificados por bismuto

En el presente trabajo se estudian catalizadores de Pt y PtBi soportados sobre carbón para la reacción de oxidación de glicerol (GLY) en fase líquida. El objetivo de este proceso es obtener selectivamente productos de alto valor agregado a partir del glicerol. Se optimizaron las condiciones de reacción las cuales resultaron ser: temperatura 60ºC,un pH de 5, una cantidad de H2O2 para obtener una concentración de 10v de O2, 100 mg de catalizador y relación molar GLY/Pt de 400. Luego de 4 h de reacción el catalizador Pt/C alcanzó una conversión de GLY de 37% con una selectividad de 57% a ácido glicérico. Se estudió el efecto de la concentración de Bi variando la relación Pt:Bi. Se observó que la relación óptima entre ambos metales fue Bi/Pt 0.5 (PtBi0.50/C). Dicho catalizador presentó una selectividad a dihidroxiacetona de un 84.5% para una conversión de 43%.In the present work carbon-supported Pt and PtBi catalysts were studied in the liquid-phase glicerol (GLY) oxidation reaction. The aim of this process is selectively obtain products of high added value from glycerol. The optimum reaction conditions were: temperature 60°C, pH = 5, H2O2 concentration so as to obtain 10vol % O2, 100 mg of catalyst and a GLY/Pt molar ratio of 400. After 4 h of reaction the Pt/C catalyst achieved a GLY conversion of 37% with a selectivity to glyceric acid of 57%. The effect of the Bi concentration was studied by varying the Pt:Bi atomic ratio. It was observed that the optimum ratio between both metals was Bi/Pt = 0.5 (PtBi0.50/C). This catalyst showed a selectivity to dihydroxyacetone of 84.5% for a GLY conversion of 43%.Trabajo publicado en Álvarez, María E., Sandra G. Casuscelli, Mónica E. Crivello y Griselda A. Eimer (eds.). Actas del XX Congreso Argentino de Catálisis. Universidad Tecnológica Nacional, Facultad Regional Córdoba, Buenos Aires, 2017.Facultad de Ciencias Exacta

Oxidation of glycerol with H2O2 on Pb-promoted Pd/γ-Al2O3 catalysts

A series of bimetallic Pd-Pb catalysts with a constant Pd content of 1 wt% and Pb/Pd atomic ratio from 0 to 1.6 supported on γ-Al2O3 were prepared and used for glycerol oxidation with H2O2 as the oxidizing agent at atmospheric pressure, 45℃ and pH=11. The morphology and dispersion of the catalysts were characterized by scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDX) and transmission electron microscopy (TEM). The presence of an alloy phase in the bimetallic catalyst was detected by X-ray photoelectron spectroscopy (XPS). Glycerol conversion obtained with the monometallic Pd catalyst was 19%, which was increased to 100% with the addition of Pb. The four bimetallic PdPb catalysts were able to oxidize glycerol to dihydroxyacetone (DIHA) and the selectivity to DIHA reached 59%, 58%, 34% and 25% for PdPb0.25, PdPb0.50, PdPb1.00 and PdPb1.60 catalysts, respectively.Facultad de Ciencias ExactasCentro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ingenierí

An overview of the Italian forest biodiversity and its conservation level, based on the first outcomes of the 4th Habitat Report ex-Art. 17

In 2019 the 4th Report ex-Art. 17 on the conservation status (CS) of Annex I Habitats of the 92/43/EEC Directive was expected by every EU/28 country, with reference to the period 2013-18. In Italy, the process was in charge to the Italian Institute for Environmental Protection and Research (ISPRA), on behalf of the Ministry for Environment, Land and Sea Protection (MATTM), with the scientific support of the Italian Botanical Society (SBI). A large group of thematic and territorial experts elaborated the available data concerning the 124 types of terrestrial and inland water Habitats present in Italy, 39 of which are represented by Forest Habitats (Group 9),. The main aim of the work was the evaluation of the overall CS of each Habitat by Biogeographic Region (Mediterranean, Continental and Alpine), for a total amount of 294 assessments. A high proportion of these (92, corresponding to 31% of the total) referred to Forest Habitats, including 20 marginal types for which the CS was not requested. The analysis was carried out at different scales: a) administrative territory, through the data contained in the ISPRA database, whose compilation was in charge to the Regions and Autonomous Provinces; b) Natura 2000 site, with the latest updates available (Standard Data Forms updated to 2018); c) national scale, implementing the distribution maps for each Habitat based on the European grid ETRS89-LAEA5210 (10x10 km2 mesh); d) Biogeographic Region, scale of the final assessment. Cartographic outcomes, associated databases and additional data used for the assessments will be available online on the ISPRA Portal as soon as the validation process by the European Commission will be completed. A dedicated archive named "HAB_IT" has been created in the national database "VegItaly" (1), managed by the Italian Society of Vegetation Science, where the phytosociological relevés representative of the various Annex I Habitats in Italy will be archived and freely accessible. An overview of the results regarding the Forest habitats is here provided, including a comparison with the outcomes of the former reporting cycle, the 3rd Report ex-Art. 17 (2). In several cases (e.g. 9120, 91L0), the distribution maps have been remarkably improved due to better knowledge and more fitful interpretation. The conservation status resulted as Favourable (FV) for 6,7%, Inadequate (U1) for 58,7% and Bad (U1) for 32,0% of the 72 assessed forest Habitat types. In no case there was an improvement of the conservation status, while in 6 cases a worsening of the conditions resulted from the data analysis, pointing out the Habitats types with a higher need of action. Similarly to other projects carried out as a team by the network of Annex I Habitat experts of the Italian Botanical Society and the Italian Society for Vegetation Science (e.g. 3, 4), this is another step in the direction of supporting the implementation of the 92/43/EEC "Habitat" Directive in Italy and Europe. On this ground, the high biodiversity of the Italian forest Habitats could be emphasized, however results pointed out that some rare or endemic types (e.g. Alnus cordata or Betula aetnensis-dominated forests) are still scarcely acknowledged by the most prominent EU conservation tools such as the Annex I to the "Habitat" Directive. 1) F. Landucci et al. (2012) Plant Biosyst., 146(4), 756-763 2) P. Genovesi et al. (2014) ISPRA, Serie Rapporti, 194/2014 3) E. Biondi et al. (2009) Società Botanica Italiana, MATTM, D.P.N., http://vnr.unipg.it/habitat/ 4) D. Gigante et al. (2016) Plant Sociology, 53(2), 77-8

EUNIS Habitat Classification: Expert system, characteristic species combinations and distribution maps of European habitats

Aim: The EUNIS Habitat Classification is a widely used reference framework for European habitat types (habitats), but it lacks formal definitions of individual habitats that would enable their unequivocal identification. Our goal was to develop a tool for assigning vegetation‐plot records to the habitats of the EUNIS system, use it to classify a European vegetation‐plot database, and compile statistically‐derived characteristic species combinations and distribution maps for these habitats. Location: Europe. Methods: We developed the classification expert system EUNIS‐ESy, which contains definitions of individual EUNIS habitats based on their species composition and geographic location. Each habitat was formally defined as a formula in a computer language combining algebraic and set‐theoretic concepts with formal logical operators. We applied this expert system to classify 1,261,373 vegetation plots from the European Vegetation Archive (EVA) and other databases. Then we determined diagnostic, constant and dominant species for each habitat by calculating species‐to‐habitat fidelity and constancy (occurrence frequency) in the classified data set. Finally, we mapped the plot locations for each habitat. Results: Formal definitions were developed for 199 habitats at Level 3 of the EUNIS hierarchy, including 25 coastal, 18 wetland, 55 grassland, 43 shrubland, 46 forest and 12 man‐made habitats. The expert system classified 1,125,121 vegetation plots to these habitat groups and 73,188 to other habitats, while 63,064 plots remained unclassified or were classified to more than one habitat. Data on each habitat were summarized in factsheets containing habitat description, distribution map, corresponding syntaxa and characteristic species combination. Conclusions: EUNIS habitats were characterized for the first time in terms of their species composition and distribution, based on a classification of a European database of vegetation plots using the newly developed electronic expert system EUNIS‐ESy. The data provided and the expert system have considerable potential for future use in European nature conservation planning, monitoring and assessment