145 research outputs found

    Divalent Metal Organic Frameworks as Heterogeneous Oxidation Catalysts

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    [ES] Se ha desarrollado un método de síntesis "verde" de compuestos metal orgánicos en medio acuoso, a temperatura y presión ambientes, fácilmente escalable y con tiempos de cristalización muy cortos (10 min). El método se ha aplicado con éxito a la síntesis de trimesatos de metales divalentes isoreticulares y con fórmula general M3(BTC)2·12 H2O (M = Ni2+, Co2+, Cu2+ y Zn2+; BTC = trimesato). La estructura de estos materiales presenta dos tipos de centros metálicos ("puente" y "ter-minales") en proporción 2 a 1, ambos con coordinación octaédrica y unidos a 4 moléculas de H2O y a dos oxígenos carboxilato del ligando. Usando este método de síntesis, se han preparado también series de compuestos bimetálicos isoreticulares de Co-Ni y Co-Zn en todo el rango de concentraciones, así como compues-tos de Mn-Ni con una concentración máxima de Mn2+ del 50%. Mediante la combinación de difracción de rayos X (en polvo y de monocristal) y microscopía EDX/SEM se ha demostrado que los compuestos bimetálicos forman verdaderas disoluciones sólidas (no meras mezclas de fases) y que los iones metálicos se dis-tribuyen homogéneamente en todo el cristal. Además, el análisis detallado de la variación de los parámetros de celda con la composición en compuestos Co-Ni y Co-Zn aporta fuertes evidencias de que los iones Co2+ ocupan preferentemente las posiciones "terminales". Se ha evaluado la actividad de los compuestos preparados como catalizadores para la oxidación aeróbica de cumeno (CM) a cumeno hidroperóxido (CHP). El com-puesto monometálico de Co2+, Co-BTC, presentó una elevada actividad, aunque la selectividad a CHP obtenida fue relativamente baja (69%), ya que los iones Co2+ catalizan también la descomposición del CHP formado. Una buena estrategia para optimizar esta selectividad consistió en aislar los iones Co2+ en una matriz de Ni-BTC (que es inerte tanto para la oxidación de CM como para la descomposición de CHP). Así, al disminuir la concentración de iones Co2+ en compuestos bimetálicos Co-Ni se observó un aumento de la selectividad a CHP de hasta el 91% para el material con un 5% de Co. Se ha calculado que estadísticamente el 73% de los iones Co2+ en este material se encuentran aislados, por lo que la des-composición/sobreoxidación del CHP se ve muy limitada. Usando una variación del método de síntesis, se han obtenido también compuestos isoreticulares de Co2+ en los que los ligandos trimesato se han reemplazado parcialmente por ligandos isoftálico o 5-aminoisoftálico. Al utilizar estos com-puestos como catalizadores para la oxidación aeróbica de CM, se ha observado que la introducción de este segundo ligando (y en particular del 5-aminoisoftálico) en la red metal-orgánica facilita la descomposición del CHP formado y aumenta la selectividad final a 2-fenil-2-propanol (PP). Esto se ha atribuido a la creación de defectos puntuales en la red del material, que presentan una mayor actividad para la descomposición de CHP. Siguiendo con la oxidación de CM como reacción modelo, se ha evaluado la actividad catalítica de compuestos isoreticulares de cobalto con ligandos bispirazolato funcionalizados con distintos grupos (CoBPZ, CoBPZ-NO2 y CoBPZ-NH2). En este caso se ha observado una clara influencia del ligando utilizado sobre la acti-vidad catalítica y la selectividad a CHP o PP del material. Mientras que el Co-BPZ presenta una baja conversión de CM y una elevada selectividad a CHP, Co-BPZ-NH2 presenta las características opuestas: una elevada velocidad de reacción pero una baja selectividad a CHP. En este último caso, el producto mayoritario forma-do es el PP. Por último, el estudio de MOFs de cationes divalentes como catalizadores de oxidación se ha completado con una reacción de síntesis de quinazolina mediante acoplamiento oxidativo de bencilamina y 2-aminoacetofenona usando TBHP co-mo oxidante. Como catalizadores para esta reacción se ha utilizado el trimesato de[CA] S'ha desenvolupat un mètode de síntesi "verda" de compostos metall orgànics en medi aquós, a temperatura i pressió ambients, fàcilment escalable i amb temps de cristal·lització molt curts (10 min). El mètode s'ha aplicat amb èxit a la síntesi de trimesats de metalls divalents isoreticular i amb fórmula general M3(BTC)2·12 H2O (M = Ni2+, Co2+, Cu2+ y Zn2+; BTC = trimesat). L'estructura d'aquests materials presenta dos tipus de centres metàl·lics ("pon" i "terminals") en una proporció de 2 a 1, ambdós amb coordinació octaèdrica i units a 4 molècules d'aigua i a 2 oxígens carboxilat del lligand. Emprant aquest mètode de síntesi, s'han preparat també sèries de compostos bimetàl·lics isoreticular de Co-Ni i Co-Zn en tot el rang de concentracions, així com compostos de Mn-Ni amb una concentració màxima de Mn2+ del 50%. Mitjançant l'ús combinat de difracció de raigs X (en pols i de monocristall) i microscòpia EDX/SEM s'ha demostrat que els compostos bimetàl·lics formen vertaderes dissolucions sòlides (no simples mescles de fase) i que els ions metàl·lics es distribueixen homogèniament en tot el cristall. A més, l'anàlisi detallat de la variació dels paràmetres de cel·la amb la composició de compostos Co-Ni i Co-Zn aporta fortes evidències de que els ions Co2+ ocupen preferentment les posicions "terminals". S'ha avaluat l'activitat dels compostos preparats com a catalitzador per a l'oxidació aeròbica de cumè (CM) a cumè hidroperòxid (CHP). El compost monometàl·lic de Co2+, Co-BTC, presenta una elevada activitat, encara que la selectivitat a CHP obtinguda és relativament baixa (69%), ja que els ions Co2+ catalitzen també la descomposició del CHP format. Una bona estratègia per optimitzar aquesta selectivitat consisteix en aïllar els ions Co2+ en una matriu de Ni-BTC (que és inert tant per a l'oxidació de CM com per a la descomposició de CHP). Així, a mesura que disminueix la concentració d'ions Co2+ en compostos bimetàl·lics Co-Ni s'observa un augment de la selectivitat a CHP de fins el 91% per al material amb un 5% de cobalt. S'ha calculat que estadísticament el 73% dels ions Co2+ d'aquest material es troben aïllats, de manera que la descomposició/sobreoxidació del CHP es veu molt limitada. Emprant una variació del mètode de síntesi, s'han obtingut també compostosisoreticulars de Co2+ en els que els lligands trimesat s'han reemplaçat parcialment per lligands isoftàlic o 5-aminoisoftàlic. Quan aquest compostos s'usen com a catalitzadors per a l'oxidació aeròbica de CM, sobserva que la introducció d'aquest segon lligand (i en particular del 5-aminoisoftàlic) en la xarxa metallorgànica es facilita la descomposició del CHP format i augmenta la selectivitat final a 2-fenil-2-propanol (PP). Això s'ha atribuït a la creació de defectes puntuals en la xarxa del material, que presenten una major activitat per a la descomposició del CHP. Seguint amb l'oxidació de CM com a reacció model, s'ha avaluat l'activitat catalítica de compostosisoreticulars de cobalt amb lligands bispirazolat funcionalitzats amb distints grups (CoBPZ, CoBPZ-NO2 i CoBPZ-NH2). En aquest cas s'ha observat una clara influència del lligand utilitzat sobre l'activitat catalítica i la selectivitat a CHP o PP del material. Mentre que el CoBPZ presenta una baixa conversió de CM i una elevada selectivitat a CHP, CoBPZ-NH2 presenta les característiques oposades: una elevada velocitat de reacció però una baixa selectivitat a CHP. En aquest últim cas, el producte majoritari format és el PP. Per últim, l'estudi de MOFs amb cations divalent como a catalitzadors d'oxidació s'ha completat amb una reacció de síntesi de quinazolina mitjançant acoblament oxidatiu de benzilamina i 2-aminoacetofenona emprant TBHP como a oxidant. Com a catalitzadors per aquesta reacció s'ha utilitzat el trimesat de coure, HKUST-1, així com materials isoreticular amb lligands mixtes obtinguts reemplaçant pa[EN] A "green" synthesis method has been developed for the preparation of metal organic frameworks in aqueous media, which is easily scalable, at room tempera-ture, ambient pressure and very short crystallization times (10 min). This method has been successfully applied to the synthesis of isoreticular divalent metal trimesates of general formula M3(BTC)2·12 H2O (M = Ni2+, Co2+, Cu2+ y Zn2+; BTC = trimesate). The structure of these compounds features two types of metal centers ("bridging" and "terminal") in a 2 to 1 ratio, both with octahedral coordina-tion and linked to 4 water molecules and 2 carboxylate oxygens of the ligand. Using this method, two series of bimetallic isoreticular compounds of Co-Ni and Co-Zn have also been prepared in all range of compositions, as well as bimetallic Mn-Ni compounds up to a maximum concentration of 50% of Mn2+. A combined X-ray diffraction (powder and single crystal) and EDX/SEM has shown that these bimetallic compounds form true solid solutions (not simple mixture of phases) and that both ions distribute homogeneously throughout the crystal. A detailed analysis of the variation of cell parameters with the composition strongly sug-gests that Co2+ ions occupy preferentially the "terminal" positions of the frame-work. The materials obtained with the above method have been evaluated as catalysts for the aerobic oxidation of cumene (CM) to cumene hydroperoxide (CHO). The monometallic Co2+ compound, Co-BTC, showed a high catalytic activity, but a relatively low selectivity to CHP 69%), since the Co2+ ions can also catalyze the decomposition of the formed CHP. A good strategy to optimize the CHP selectivity consisted in isolating the Co2+ ions into a Ni-BTC (which is inert for both CM oxidation and CHP decomposition). In this way, as the concentration of Co2+ ions in the bimetallic Co-Ni compound decreases, a parallel increase of the CHP selec-tivity was observed, up to 91% for the material with 5% of Co. In this compound, 73% of the total Co2+ ions are statistically isolated, so that decomposi-tion/overoxidation of CHP is unlikely to occur. By using a variation of the above synthesis method, additional isoreticular Co2+ compounds have been prepared in which the trimesate ligands have been partially replaced by either isophthalic or 5-aminoisophthalic. When these compounds were used as catalysts for the aerobic oxidation of cumene, we observed that the introduction of this second ligand (in particular in the case of 5-aminoisophthalic) into the framework facilitates decomposition of CHP and in-creases the final selectivity to 2-phenyl-2-propanol (PP). This has been attributed to the progressive creation of point defects in the framework, having a higher activity for CHP decomposition. Following with the aerobic oxidation of CM as model reaction, we evaluated the catalytic activity of isoreticular cobalt compounds having bispyrazolate ligands bearing differnent functional groups (CoBPZ, CoBPZ-NO2 and CoBPZ-NH2). In this case, there is a clear influence of the ligand used on the catalytic activity of the material and the obtained selectivity to CHP or PP. While CoBPZ showed a low CM conversion and high CHP selectivity, the opposite properties are obtained for the Co-BPZ-NH2: i.e., a high reaction rate but a low CHP selectivity. In this latter case, the major product of the reaction was PP. Finally, the evaluation of divalent MOFs as oxidation catalysts has been complet-ed by addressing the synthesis of quinazoline through the oxidative coupling reaction of benzylamine and 2-aminoacetophenone using TBHP as oxidant. As catalysts for this reaction we have used a copper trimesate, HKUST-1, as well as isoreticular mixed-ligand compounds obtained by partially replacing trimesate ligands by 5-hydroxyisophthalic (OH-isophthalic).Nowacka, AE. (2019). Divalent Metal Organic Frameworks as Heterogeneous Oxidation Catalysts [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/129872TESI

    Stosunek do edukacji finansowej w obszarze zarządzania finansami osobistymi a poziom transakcyjnego wykluczenia finansowego osób bezrobotnych w świetle badań własnych

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    Theoretical background: The attitude to financial education in the area of personal finance management can be determined by many factors, i.a. the socio-demographic ones and the degree of transactional financial exclusion. The phenomenon of is related to the degree of banking.Purpose of the article: Examination of the relationship between the attitude of the unemployed to the financial education in the area of personal finance management and different levels of transactional financial exclusion. The study focuses on one of the segments of financial exclusion, i.e. banking financial exclusion in the area of access to payment transactions, measured by the level of banking.Research methods: The analysis of the attitude to financial education in the area of personal finance management as well as the levels of transactional financial exclusion was based on the own research and review of the literature on the subject. The data obtained as a result of the study with the use of a questionnaire on the 350 unemployed people registered at the Municipal Employment Office in Płock were used to verify three research hypotheses.Main findings: The obtained results of the analysis indicate a relationship between the attitude to financial education in the area of personal finance management and selected socio-demographic characteristics of the unemployed (age, education and the period of registration with the employment office) and three levels of banking. However, no statistically significant dependence was found between the subjective assessment of financial skills in the area of personal finance management and the degree of transactional financial exclusion. Taking into account the results of the analysis, it seems essential to undertake educational initiatives among the unemployed aimed at limiting the degree of transactional financial exclusion.Uzasadnienie teoretyczne: Stosunek do edukacji finansowej w obszarze zarządzania finansami osobistymi może być determinowany wieloma czynnikami, m.in. społeczno-demograficznymi oraz stopniem transakcyjnego wykluczenia finansowego. Zjawisko to związane jest ze stopniem ubankowienia.Cel artykułu: Określenie stosunku osób bezrobotnych do edukacji finansowej w obszarze zarządzania finansami osobistymi w zależności od poziomu transakcyjnego wykluczenia finansowego. W opracowaniu skoncentrowano się na jednym z segmentów wykluczenia finansowego, tzn. bankowym wykluczeniu finansowym w zakresie dostępu do transakcji płatniczych, mierzonym poziomem ubankowienia.Metody badawcze: Analiza stosunku do edukacji finansowej w obszarze zarządzania finansami osobistymi oraz do poziomów transakcyjnego wykluczenia finansowego została oparta na badaniach własnych i przeglądzie literatury przedmiotu. Dane uzyskane w wyniku przeprowadzonego badania z wykorzystaniem kwestionariusza ankiety na próbie 350 osób bezrobotnych zarejestrowanych w Miejskim Urzędzie Pracy w Płocku wykorzystano do weryfikacji trzech hipotez badawczych.Główne wnioski: Uzyskane wyniki badania wskazują na związek stosunku do edukacji finansowej w obszarze zarządzania finansami osobistymi z wybranymi cechami społeczno-demograficznymi osób bezrobotnych (takimi jak wiek, wykształcenie i okres zarejestrowania w urzędzie pracy) oraz z trzema poziomami ubankowienia. Nie stwierdzono natomiast istotnej statystycznie zależności między oceną umiejętności finansowych w obszarze zarządzania finansami osobistymi a stopniem transakcyjnego wykluczenia finansowego. Biorąc pod uwagę wyniki przeprowadzonej analizy, zasadne wydaje się podejmowanie inicjatyw edukacyjnych wśród osób bezrobotnych, mających na celu ograniczanie stopnia transakcyjnego wykluczenia finansowego

    Socio-demographic determinants of financial exclusion of the unemployed on the local labour market: a case study

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    Motivation: People who experience problems accessing financial products and services in a suitable form cannot fully participate in economic and social lives. The groups particularly vulnerable to financial exclusion in the area of banking services and saving products are the unemployed.Aim: The aim of the study is to determine the relationship between socio-demographic determinants and selected areas of financial exclusion related to banking usage and the propensity to save. The empirical basis of the issues raised in this article is the study of the literature and the findings of the survey conducted among 350 unemployed persons registered at the Municipal Labour Office in Płock in the period from September to October 2018.Results: Education, age, reasons and the period of registration at the labour office exert an impact on the selected areas of financial exclusion of the unemployed regarding the bank usage and the propensity to save. The results of the study indicate that on the local market education was the feature that most determined the degree of banking usage, the refusal to conduct banking services or the propensity to save among the unemployed

    Polish infection control nurses’ burnout in the context of cooperation of different hospital professionals during COVID-19 pandemic

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    Backgrounds: Infection control nurses’ job are crucial for patient and healthcare workers safety. However, effective infections prevention is based on the interdisciplinary team work, involving almost all hospital employees professionals. Difficulties in cooperation in such a team, especially prolonged ones, as well as crisis situations, may cause burnout. The aim of the study was to determine burnout among infection control nurses working during the COVID-19 pandemic in the context of difficulties in cooperation with different professionals working in hospitals. Methods: The observational study was conducted between May and September 2021, using an online survey questionnaire consisting of two parts: describing difficulties in ICNs cooperation with different hospital professionals and Maslach Inventory Burnout scale, describing emotional exhaustion (EE), depersonalization (DP) and personal accomplishment rates (PA). Correctly completed online surveys were obtained from 177 participants. Results: Most of the respondents (176 of 177) were women, working in public hospitals (81.48%). All respondents had considerable experience in work as nurses - the median was 30 years. However, the median experience in the ICNs position was 12 years. Median age of respondents was 51 years. The median level of EE was 31.0, w ith the range 23.0 to 39.0. For DP it was 5.0, with the range 3.0 and 11.5, while for PA – 24.0 (19.0–29.0). The highest values of EE were observed in the context of high level of difficulties with cooperation with management – the median was 36.0. DP was lowest among nurses declaring the lowest difficulties in cooperation with doctors. For PA the lowest level was observed in the group declaring high difficulties in the cooperation with doctors – median 22.0, with range 14.0–29.0. Conclusions: The surveyed ICNs had higher rates of EE and PA than nurses working with patients, both before and during the pandemic. The level of burnout found in the ICN study group reached a level correlating in other studies with the intention to quit the job. The obtained results indicate the need to include effective training in the skills of working in multidisciplinary teams and the art of communication and achieving goals by ICNs

    Bezpieczeństwo usług bankowości internetowej i terminalowej w opinii klientów banków spółdzielczych

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    Internet and terminal banking allows to overcome numerous spatial, temporal and orga­nizational constraints in the banking business. It is important from the point of view of customers of cooperative banks, often living in small towns, away from the bank branch. The purpose of this thesis is to present feedback of cooperative banks customers on the security of internet and terminal banking services. The analyses were based on statistical data involving customers using electronic distribution channels of banking services with regard to their socio-demographic characteristics

    Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal Organic Frameworks Prepared by a Facile Green Aqueous Synthesis

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    "This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry & Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acssuschemeng.8b06472"[EN] Co-Ni and Mn-Ni bimetallic trimesate MOFs prepared by a fast aqueous synthesis method are excellent and reusable catalysts for the selective aerobic oxidation of cumene to cumene hydroperoxide (CHP). Isolation of Co2+ (or Mn2+) in an inert Ni-BTC framework is a good strategy to optimize CHP selectivity above 90%: since only Co2+ sites catalyze CHP decomposition, a drop of the CHP selectivity is observed as the cobalt content in the bimetallic MOF increases. The statistical probability of having isolated Co2+ sites is calculated as a function of the total cobalt content of the bimetallic compound, assuming homogeneous distribution of Co2+ ions in the Ni-BTC framework and preferential occupation of terminal sites. Thus, in our best sample, with a Co:Ni ratio of 5:95, 73% of the total Co2+ ions are isolated so that CHP decomposition/overoxidation processes at the surface of the catalyst are not likely to occur before CHP desorption. This can explain the excellent CHP selectivity (91%) attained over this material. This "site isolation" effect is further supported by similar findings on Mn-Ni bimetallic compounds.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 641887 (project acronym: DEFNET) and the Spanish Government through projects MAT2017-82288-C2-1-P and Severo Ochoa (SEV-2016-0683).Nowacka, AE.; Briantais, P.; Prestipino, C.; Llabrés I Xamena, FX. (2019). Selective Aerobic Oxidation of Cumene to Cumene Hydroperoxide over Mono- and Bimetallic Trimesate Metal Organic Frameworks Prepared by a Facile Green Aqueous Synthesis. ACS Sustainable Chemistry & Engineering. 7(8):7708-7715. https://doi.org/10.1021/acssuschemeng.8b06472S770877157

    Facile "Green" Aqueous Synthesis of Mono- and Bimetallic Trimesate Metal-Organic Frameworks

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    [EN] Various isoreticular monometallic (Co2+, Ni2+, Cu2+, and Zn2+) and bimetallic (Co-Ni, Co-Zn, Mn-Ni) trimesate MOFs have been prepared by a fast (10 min) and green synthesis method from aqueous solutions, at room temperature and ambient pressure. A combined XRD and SEM/EDX analysis clearly revealed bimetallic compounds form true solid solutions rather than a simple physical mixture of pure-phase monometallic compounds. Moreover, a detailed evaluation of the evolution of cell parameters with the composition provides strong evidence indicating a preferential occupation of one crystallographic position (bidentate terminal sites) by Co2+ (or Mn2+) ions. This leads to a precise and predictable array of metal ions in the framework, which can be finely tuned by changing the overall composition of the bimetallic MOF. Implications are envisaged in the design and catalytic properties of well-defined single-site catalysts.This project has received funding from the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No. 641887 (project acronym: DEFNET) and the Spanish Government through projects MAT2017-82288-C2-1-P and Severo Ochoa (SEV-2016-0683). The Microscopy Service of the Universitat Politecnica de Valencia is gratefully acknowledged for the electron microscopy measurements.Nowacka, AE.; Briantais, P.; Prestipino, C.; Llabrés I Xamena, FX. (2019). Facile "Green" Aqueous Synthesis of Mono- and Bimetallic Trimesate Metal-Organic Frameworks. Crystal Growth & Design. 19(9):4981-4989. https://doi.org/10.1021/acs.cgd.9b00237S4981498919
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