: Ceria loaded with noble metals (Cu, Au) is a highly active material for the low-temperature water-gas shift reaction (LT-WGSR), but nevertheless details of the metal support interaction as well as the role of the ceria surface termination and the metal loading are still unclear. Using operando Raman and UV/Vis spectroscopy combined with theoretical density functional theory (DFT) calculations, we aim at a molecular-level understanding of LT-WGSR catalysts. In particular, by using this combined approach, we are able to draw conclusions about the reducibility state of the ceria support during reaction conditions. Our results show that the defect formation energy of the support does not play a major role for the WGSR, but rather other reaction steps such as the dissociation of water or the desorption of CO 2 .
{"title":"Combined DFT and operando Spectroscopic Study of the Water-Gas Shift Reaction over Ceria based Catalysts: The Role of the Noble Metal and Ceria Faceting","authors":"M. Ziemba, D. Stark, C. Hess","doi":"10.3390/eccs2020-07531","DOIUrl":"https://doi.org/10.3390/eccs2020-07531","url":null,"abstract":": Ceria loaded with noble metals (Cu, Au) is a highly active material for the low-temperature water-gas shift reaction (LT-WGSR), but nevertheless details of the metal support interaction as well as the role of the ceria surface termination and the metal loading are still unclear. Using operando Raman and UV/Vis spectroscopy combined with theoretical density functional theory (DFT) calculations, we aim at a molecular-level understanding of LT-WGSR catalysts. In particular, by using this combined approach, we are able to draw conclusions about the reducibility state of the ceria support during reaction conditions. Our results show that the defect formation energy of the support does not play a major role for the WGSR, but rather other reaction steps such as the dissociation of water or the desorption of CO 2 .","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129789132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"BioICEP. Bio Innovation of A Circular Economy for Plastics","authors":"P. Ferrero, P. Ferrer","doi":"10.3390/ECCS2020-07637","DOIUrl":"https://doi.org/10.3390/ECCS2020-07637","url":null,"abstract":"","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"512 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133124178","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: Over the years, organodiselenides have emerged as the biologically relevant class of molecules. On the one hand, such compounds are known for pro-oxidant effects leading to toxicity in biological systems. On the other hand, there are growing evidences about their bio-mimetic activities as catalysts such as glutathione peroxidase (GPx)-like activity. Our recent work has explored this paradoxical behavior of diselenides in developing antioxidants and/or anticancer agents. For this purpose, a number of alkyl and aryl diselenides have been evaluated in different biological models. The results have shown that aryl diselenides, in particular pyridinediselenides, altered the ratio of the intracellular thiol redox pairs of glutathione (GSH) and glutathione disulfide (GSSG) towards reduction (antioxidant) rather than oxidation (pro-oxidant) to protect normal cells against radiation damage and to induce cytotoxicity in tumor cells. Further, these studies have also postulated that the intracellular redox state, the level of thioredoxin reductase (TrxR), and reductive intermediates (e.g., selenol and/or selone) might play a very important role in the manifestation of the toxicities of aryl diselenides in cells.
{"title":"Paradoxical Behavior of Organodiselenides: Pro-oxidant to Antioxidant","authors":"V. V. Gandhi, K. Priyadarsini, A. Kunwar","doi":"10.3390/eccs2020-07552","DOIUrl":"https://doi.org/10.3390/eccs2020-07552","url":null,"abstract":": Over the years, organodiselenides have emerged as the biologically relevant class of molecules. On the one hand, such compounds are known for pro-oxidant effects leading to toxicity in biological systems. On the other hand, there are growing evidences about their bio-mimetic activities as catalysts such as glutathione peroxidase (GPx)-like activity. Our recent work has explored this paradoxical behavior of diselenides in developing antioxidants and/or anticancer agents. For this purpose, a number of alkyl and aryl diselenides have been evaluated in different biological models. The results have shown that aryl diselenides, in particular pyridinediselenides, altered the ratio of the intracellular thiol redox pairs of glutathione (GSH) and glutathione disulfide (GSSG) towards reduction (antioxidant) rather than oxidation (pro-oxidant) to protect normal cells against radiation damage and to induce cytotoxicity in tumor cells. Further, these studies have also postulated that the intracellular redox state, the level of thioredoxin reductase (TrxR), and reductive intermediates (e.g., selenol and/or selone) might play a very important role in the manifestation of the toxicities of aryl diselenides in cells.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"45 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127279084","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A. Georgiadis, N. Charisiou, I. Yentekakis, M. Goula
: Removal of hydrogen sulfide (H 2 S) from gas streams with varying overall pressure and H 2 S concentration is a long-standing challenge faced by the oil and gas industries. The present work focuses on H 2 S capture using metal-organic frameworks (MOFs), in an effort to shed light on their potential as adsorbents in the field of gas storage and separation. MOFs hold great promise as they make possible the design of structures from organic and inorganic units but also, they have provided an answer to a long-time challenging objective, i.e., how to design extended structures of materials. Moreover, the functionalization of the MOF’s surface can result in increased H 2 S uptake. For example, the insertion of 1% of a fluorinated linker in MIL-101(Cr)-4F(1%) allows for enhanced H 2 S capture. Although noticeable efforts have been made in studying the adsorption capacity of H 2 S using MOFs, there is a clear need for gaining a deeper understanding in terms of their thermal conductivities and specific heats in order to design more stable adsorption beds, experiencing high exothermicity. Simply put, the exothermic nature of adsorption means that sharp rises in temperature can negatively affect the bed stability in the absence of sufficient heat transfer. The work presented herein provides a detailed discussion, by thoroughly combining the existing literature, on new developments in MOFs for H 2 S removal, and tries to provide insight into new areas for further research.
{"title":"Removal of Hydrogen Sulfide (H2S) Using MOFs: A Review of the Latest Developments","authors":"A. Georgiadis, N. Charisiou, I. Yentekakis, M. Goula","doi":"10.3390/eccs2020-07586","DOIUrl":"https://doi.org/10.3390/eccs2020-07586","url":null,"abstract":": Removal of hydrogen sulfide (H 2 S) from gas streams with varying overall pressure and H 2 S concentration is a long-standing challenge faced by the oil and gas industries. The present work focuses on H 2 S capture using metal-organic frameworks (MOFs), in an effort to shed light on their potential as adsorbents in the field of gas storage and separation. MOFs hold great promise as they make possible the design of structures from organic and inorganic units but also, they have provided an answer to a long-time challenging objective, i.e., how to design extended structures of materials. Moreover, the functionalization of the MOF’s surface can result in increased H 2 S uptake. For example, the insertion of 1% of a fluorinated linker in MIL-101(Cr)-4F(1%) allows for enhanced H 2 S capture. Although noticeable efforts have been made in studying the adsorption capacity of H 2 S using MOFs, there is a clear need for gaining a deeper understanding in terms of their thermal conductivities and specific heats in order to design more stable adsorption beds, experiencing high exothermicity. Simply put, the exothermic nature of adsorption means that sharp rises in temperature can negatively affect the bed stability in the absence of sufficient heat transfer. The work presented herein provides a detailed discussion, by thoroughly combining the existing literature, on new developments in MOFs for H 2 S removal, and tries to provide insight into new areas for further research.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126454849","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
S. Olshannikova, V. Koroleva, M. Holyavka, A. Pashkov, V. Artyukhov
: Plant enzymes such as ficin (EC 3.4.22.3), papain (EC 3.4.22.2) and bromelain (EC 3.4.22.4) are obtained from tropical plants. These biocatalysts belong to thiol proteases, in the active center of which cysteine is contained. Ficin, papain and bromelain have a wide substrate specificity, which provides a demand for their use in various industries. Enzymes in the free state are less commonly used; immobilized biocatalysts are the preferred form. The aim of this work was to determine the optimal concentration of a crosslinking agent in the covalent immobilization of ficin, papain and bromelain on a chitosan matrix. Ficin, papain and bromelain (Sigma) were chosen as objects of study. An acid-soluble chitosan (350 kDa, Bioprogress CJSC) was used as an immobilization carrier. The concentration range of glutaraldehyde (crosslinking agent) ranged from 1 to 25%. Suitable concentrations of glutaraldehyde for covalent immobilization were identified by the optimal ratio of protein content (mg per g of carrier), total activity (in units per ml of solution) and specific activity (in units per mg of protein). It was shown that for covalent immobilization of ficin and bromelain on a chitosan matrix, it is most promising to use 10% glutaraldehyde. For immobilization of papain on chitosan by covalent means, the concentration of glutaraldehyde equal to 20% is optimal.
{"title":"Covalent Immobilization of Thiol Proteases on Chitosan","authors":"S. Olshannikova, V. Koroleva, M. Holyavka, A. Pashkov, V. Artyukhov","doi":"10.3390/eccs2020-07527","DOIUrl":"https://doi.org/10.3390/eccs2020-07527","url":null,"abstract":": Plant enzymes such as ficin (EC 3.4.22.3), papain (EC 3.4.22.2) and bromelain (EC 3.4.22.4) are obtained from tropical plants. These biocatalysts belong to thiol proteases, in the active center of which cysteine is contained. Ficin, papain and bromelain have a wide substrate specificity, which provides a demand for their use in various industries. Enzymes in the free state are less commonly used; immobilized biocatalysts are the preferred form. The aim of this work was to determine the optimal concentration of a crosslinking agent in the covalent immobilization of ficin, papain and bromelain on a chitosan matrix. Ficin, papain and bromelain (Sigma) were chosen as objects of study. An acid-soluble chitosan (350 kDa, Bioprogress CJSC) was used as an immobilization carrier. The concentration range of glutaraldehyde (crosslinking agent) ranged from 1 to 25%. Suitable concentrations of glutaraldehyde for covalent immobilization were identified by the optimal ratio of protein content (mg per g of carrier), total activity (in units per ml of solution) and specific activity (in units per mg of protein). It was shown that for covalent immobilization of ficin and bromelain on a chitosan matrix, it is most promising to use 10% glutaraldehyde. For immobilization of papain on chitosan by covalent means, the concentration of glutaraldehyde equal to 20% is optimal.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"98 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123370513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Anastasios I. Tsiotsias, N. Charisiou, I. Yentekakis, M. Goula
The conversion of CO2, captured from flue gases, into synthetic natural gas (SNG) aims to create a closed carbon cycle, where excess H2 produced from renewables is utilized to transform CO2 released from existing conventional power plants into a reliable and high energy density carrier, that is CH4. In the last five years, extensive research effort has been dedicated to the synthesis and optimization of composite materials for the realization of this process. These materials, also known as dual-function materials or DFMs, typically consist of an alkaline metal oxide or carbonate phase, along with a Ru or Ni metallic phase supported on a high surface area carrier. The DFMs incorporate both sorptive and catalytic capabilities, capturing the CO2 in the initial sorption step and then converting it into CH4 upon H2 inflow. The dispersion of the sorptive and catalytically active phases, the CO2 affinity of the alkaline phase, the reducibility of the supported metals, and the selectivity towards CH4 production are some of the parameters influencing their performance. Hereby, we aim to present the most recent works dedicated to the development and optimization of such dual-function materials to be used in the combined capture and methanation of CO2.
{"title":"Capture and Methanation of CO2 Using Dual-Function Materials (DFMs)","authors":"Anastasios I. Tsiotsias, N. Charisiou, I. Yentekakis, M. Goula","doi":"10.3390/eccs2020-07567","DOIUrl":"https://doi.org/10.3390/eccs2020-07567","url":null,"abstract":"The conversion of CO2, captured from flue gases, into synthetic natural gas (SNG) aims to create a closed carbon cycle, where excess H2 produced from renewables is utilized to transform CO2 released from existing conventional power plants into a reliable and high energy density carrier, that is CH4. In the last five years, extensive research effort has been dedicated to the synthesis and optimization of composite materials for the realization of this process. These materials, also known as dual-function materials or DFMs, typically consist of an alkaline metal oxide or carbonate phase, along with a Ru or Ni metallic phase supported on a high surface area carrier. The DFMs incorporate both sorptive and catalytic capabilities, capturing the CO2 in the initial sorption step and then converting it into CH4 upon H2 inflow. The dispersion of the sorptive and catalytically active phases, the CO2 affinity of the alkaline phase, the reducibility of the supported metals, and the selectivity towards CH4 production are some of the parameters influencing their performance. Hereby, we aim to present the most recent works dedicated to the development and optimization of such dual-function materials to be used in the combined capture and methanation of CO2.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"70 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124230091","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
: This paper presents graphite/paraffin composite electrodes modified with microparticles of nickel (Ni) and Ni-Fe alloy anchored in reduced graphene oxide (rGO); these electrodes were made by electrosynthesis. Firstly, the electrodeposition of reduced graphene oxide was made by cyclic voltammetry (CV) onto the graphite/paraffin electrodes’ surface. After electrodeposition of the rGO, iron and nickel were electrodeposited by CV with successive scans. Finally, the formation of iron-nickel oxyhydroxide on the electrode surface was performed by cyclic voltammetry in alkaline medium. The composites were investigated by field emission gun scanning electron microscopy (FEG-SEM); it was observed that the Ni microparticles had spherical shapes, while the Ni-Fe alloy did not present a defined shape. The composite electrodes were used to analysis ethanol and methanol electrooxidation in an alkaline medium of 0.10 mol L − 1 of NaOH in a potential range of from − 0.20 to 1.0 V (vs. Ag/AgCl) at 50 mV s − 1 by CV. The electrodes were able to make the electrooxidation of ethanol at a potential of around 0.57 V for the electrode constituted by the Ni-Fe alloy and around 0.61 V for the electrode modified with Ni, and for methanol in a potential around 0.57 V for the Ni-Fe alloy and around 0.66 V for the Ni electrode. The Ni-Fe alloy electrodes showed the electrocatalysis of the alcohols in relation to Ni electrodes.
{"title":"Electrocatalysis of Ethanol and Methanol Electrooxidation by Composite Electrodes with NiOOH/FeOOH Supported on Reduced Graphene Oxide onto Composite Electrodes","authors":"J. Oliveira, A. C. Sá, L. Paim","doi":"10.3390/eccs2020-07523","DOIUrl":"https://doi.org/10.3390/eccs2020-07523","url":null,"abstract":": This paper presents graphite/paraffin composite electrodes modified with microparticles of nickel (Ni) and Ni-Fe alloy anchored in reduced graphene oxide (rGO); these electrodes were made by electrosynthesis. Firstly, the electrodeposition of reduced graphene oxide was made by cyclic voltammetry (CV) onto the graphite/paraffin electrodes’ surface. After electrodeposition of the rGO, iron and nickel were electrodeposited by CV with successive scans. Finally, the formation of iron-nickel oxyhydroxide on the electrode surface was performed by cyclic voltammetry in alkaline medium. The composites were investigated by field emission gun scanning electron microscopy (FEG-SEM); it was observed that the Ni microparticles had spherical shapes, while the Ni-Fe alloy did not present a defined shape. The composite electrodes were used to analysis ethanol and methanol electrooxidation in an alkaline medium of 0.10 mol L − 1 of NaOH in a potential range of from − 0.20 to 1.0 V (vs. Ag/AgCl) at 50 mV s − 1 by CV. The electrodes were able to make the electrooxidation of ethanol at a potential of around 0.57 V for the electrode constituted by the Ni-Fe alloy and around 0.61 V for the electrode modified with Ni, and for methanol in a potential around 0.57 V for the Ni-Fe alloy and around 0.66 V for the Ni electrode. The Ni-Fe alloy electrodes showed the electrocatalysis of the alcohols in relation to Ni electrodes.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123627071","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
2020 Abstract: The depletion of fossil fuels and the growing concerns related to the environmental impact of their processing has progressively switched the interest towards the utilization of biomass-derived materials for a large variety of processes. Among them, biogas, which is a CH 4 -rich gas deriving from anaerobic digestion of biomass, has acquired a lot of interest as a feedstock for reforming processes. The main issue in employing biogas is related to the carbon deposition and active metal sintering, which are both responsible for the deactivation of the catalyst. In this work, bimetallic and monometallic Rh- and Ni-based formulations were supported on alumina and ceria with the aim of evaluating their activity and stability in biogas oxidative steam reforming. The Rh addition to the monometallic Ni/ -Al 2 O 3 formulation enhances its catalytic performances; nevertheless, this induces a higher coke deposition, thus suggesting a preferential coke formation on Rh sites. The initial activity of the CeO 2 -supported catalysts was found to be lower than the Al 2 O 3 supported catalysts, but the 5%Ni/CeO 2 sample showed a very good stability during the test and, despite the lower activity, 0.5%Rh-5%Ni/CeO 2 did not show coke deposition. The results suggest that the promotion of Ni/CeO 2 catalysts with other active metals could lead to the selection of a highly stable and performing formulation for biogas oxidative for the alumina-supported catalysts: CeO 2 -supported samples did not produce CO 2 during the TPO experiment, thus confirming the lack of coke deposition in the catalytic bed; for this reason, these latter profiles are not shown below. As it is possible to see, the results are in agreement with the hypotheses made when observing the pressure drop trends: the sample 0.5%Rh/Al 2 O 3 induced the highest coke formation, while a smaller production was observed on 0.5%Rh-5%Ni/Al 2 O 3 ; and a very small quantity of coke was gasified during TPO on the 5%Ni/Al 2 O 3 sample, thus again suggesting metal sintering as a different reason for the catalyst deactivation. Furthermore, these results suggest that coke deposition occurs preferentially on Rh sites rather than Ni ones.
{"title":"Coke-Resistant Rh and Ni Catalysts Supported on g-Al2O3 and CeO2 for Biogas Oxidative Steam Reforming","authors":"Simona Renda, A. Ricca, V. Palma","doi":"10.3390/eccs2020-07588","DOIUrl":"https://doi.org/10.3390/eccs2020-07588","url":null,"abstract":"2020 Abstract: The depletion of fossil fuels and the growing concerns related to the environmental impact of their processing has progressively switched the interest towards the utilization of biomass-derived materials for a large variety of processes. Among them, biogas, which is a CH 4 -rich gas deriving from anaerobic digestion of biomass, has acquired a lot of interest as a feedstock for reforming processes. The main issue in employing biogas is related to the carbon deposition and active metal sintering, which are both responsible for the deactivation of the catalyst. In this work, bimetallic and monometallic Rh- and Ni-based formulations were supported on alumina and ceria with the aim of evaluating their activity and stability in biogas oxidative steam reforming. The Rh addition to the monometallic Ni/ -Al 2 O 3 formulation enhances its catalytic performances; nevertheless, this induces a higher coke deposition, thus suggesting a preferential coke formation on Rh sites. The initial activity of the CeO 2 -supported catalysts was found to be lower than the Al 2 O 3 supported catalysts, but the 5%Ni/CeO 2 sample showed a very good stability during the test and, despite the lower activity, 0.5%Rh-5%Ni/CeO 2 did not show coke deposition. The results suggest that the promotion of Ni/CeO 2 catalysts with other active metals could lead to the selection of a highly stable and performing formulation for biogas oxidative for the alumina-supported catalysts: CeO 2 -supported samples did not produce CO 2 during the TPO experiment, thus confirming the lack of coke deposition in the catalytic bed; for this reason, these latter profiles are not shown below. As it is possible to see, the results are in agreement with the hypotheses made when observing the pressure drop trends: the sample 0.5%Rh/Al 2 O 3 induced the highest coke formation, while a smaller production was observed on 0.5%Rh-5%Ni/Al 2 O 3 ; and a very small quantity of coke was gasified during TPO on the 5%Ni/Al 2 O 3 sample, thus again suggesting metal sintering as a different reason for the catalyst deactivation. Furthermore, these results suggest that coke deposition occurs preferentially on Rh sites rather than Ni ones.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"24 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125918438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
C. Stasi, Marta Cortese, G. Greco, Belén González, V. Palma, J. Manyà
: In this work, different biochar-based metal catalysts were tested for mid-temperature (400 − 600 °C) acetic acid steam reforming. K, Co, Ce, Fe and Ni were chosen as active phases for the production of the studied catalysts. Their performance was evaluated in terms of acetic acid conversion, hydrogen yield, acetone yield, and stability. The best outcomes were obtained for the nickel-based catalysts, which exhibited high conversion (>90%) along with insignificant deactivation rates. Nevertheless, for relatively low nickel loadings, a certain extent of coke deposition was deduced from the observed fluctuations in pressure drop. A 10 wt.% nickel loading appeared to be a reasonable tradeoff between activity and coke production. After the identification of the optimal loading, four bimetallic catalysts were produced with the aim of improving the original activity of the nickel-based one. The cobalt–nickel catalysts showed the most stable behavior with a constant conversion degree (98%) in the range of 475–600 °C.
{"title":"Activated Biochar-Based Metal Catalysts for Steam Reforming of Pyrolysis Bio-Oil Model Compound","authors":"C. Stasi, Marta Cortese, G. Greco, Belén González, V. Palma, J. Manyà","doi":"10.3390/eccs2020-07536","DOIUrl":"https://doi.org/10.3390/eccs2020-07536","url":null,"abstract":": In this work, different biochar-based metal catalysts were tested for mid-temperature (400 − 600 °C) acetic acid steam reforming. K, Co, Ce, Fe and Ni were chosen as active phases for the production of the studied catalysts. Their performance was evaluated in terms of acetic acid conversion, hydrogen yield, acetone yield, and stability. The best outcomes were obtained for the nickel-based catalysts, which exhibited high conversion (>90%) along with insignificant deactivation rates. Nevertheless, for relatively low nickel loadings, a certain extent of coke deposition was deduced from the observed fluctuations in pressure drop. A 10 wt.% nickel loading appeared to be a reasonable tradeoff between activity and coke production. After the identification of the optimal loading, four bimetallic catalysts were produced with the aim of improving the original activity of the nickel-based one. The cobalt–nickel catalysts showed the most stable behavior with a constant conversion degree (98%) in the range of 475–600 °C.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130607594","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
L. Gomes, Rafaella G. Angelino, José Neto, I. D. Leo, C. Santi, Vanessa Nascimento
: In this work, a new ecological approach to the selenofunctionalization of alkenes has been described using I 2 as catalyst, DMSO as oxidant, under microwave irradiation (MW) in a solvent-and metal-free method. The general idea is to combine organoselenium compounds and triazole nuclei to obtain molecules capable of becoming a powerful class due to their potential pharmacological activity. However, most methods that involve the functionalization of alkenes are generally mediated by the use of transition metals or reagents in large stoichiometric quantities. Thus, the development of direct, clean and environmentally appropriate procedures, which are in accordance with the principles of green chemistry, for the synthesis of these compounds remains highly desirable. Thus, the present work developed the synthesis of β -amino selenides with only 20 minutes of reaction time, following the conditions previously mentioned. In addition, encouraged by these results, the scope of the reaction was expanded using also diorganoil disulfides and ditellurides, obtaining molecules with good to excellent yields. Finally, compared to traditional methods, our methodology is a lightweight, metal-free, simple and practical tool for the selenofunctionalization of alkenes and is considered a promising alternative in the development of new drugs with potential biological activities.
{"title":"Ecofriendly Catalytic Aminoselenation of Alkenes: A Green Alternative for Obtaining Potentially Active Compounds","authors":"L. Gomes, Rafaella G. Angelino, José Neto, I. D. Leo, C. Santi, Vanessa Nascimento","doi":"10.3390/eccs2020-07580","DOIUrl":"https://doi.org/10.3390/eccs2020-07580","url":null,"abstract":": In this work, a new ecological approach to the selenofunctionalization of alkenes has been described using I 2 as catalyst, DMSO as oxidant, under microwave irradiation (MW) in a solvent-and metal-free method. The general idea is to combine organoselenium compounds and triazole nuclei to obtain molecules capable of becoming a powerful class due to their potential pharmacological activity. However, most methods that involve the functionalization of alkenes are generally mediated by the use of transition metals or reagents in large stoichiometric quantities. Thus, the development of direct, clean and environmentally appropriate procedures, which are in accordance with the principles of green chemistry, for the synthesis of these compounds remains highly desirable. Thus, the present work developed the synthesis of β -amino selenides with only 20 minutes of reaction time, following the conditions previously mentioned. In addition, encouraged by these results, the scope of the reaction was expanded using also diorganoil disulfides and ditellurides, obtaining molecules with good to excellent yields. Finally, compared to traditional methods, our methodology is a lightweight, metal-free, simple and practical tool for the selenofunctionalization of alkenes and is considered a promising alternative in the development of new drugs with potential biological activities.","PeriodicalId":151361,"journal":{"name":"Proceedings of 1st International Electronic Conference on Catalysis Sciences","volume":"60 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2020-11-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116586268","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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