S. Evstropiev, A. Shelemanov, Igor Bagrov, A. Karavaeva, Kseniya Portnova, N. Nikonorov
Disperse porous Mn-doped ZnO-ZrO2 nanocomposites were prepared using the facile polymer-salt method. The effect of Mn content on the crystal structure, composite morphologies, their ability to photogenate the singlet oxygen, luminescence properties, and bactericidal activities were studied. The crystal structure and morphology of these materials were investigated using XRD and SEM analysis. It was found that obtained nanocomposites consist of small (~9 nm) hexagonal ZnO and fine ZrO2 crystals and the embedding of Mn ions expands the crystal cells of ZnO crystals. Photoluminescence spectra indicate the presence of different structural defects (interstitial Zn ions and oxygen vacancies in ZnO and oxygen vacancies in ZrO2 crystals). Mn-doped ZnO-ZrO2 nanocomposites can photogenerate singlet oxygen under visible (λ = 405 nm) irradiation. The increased power density of the exciting blue (λ = 405 nm) light significantly enhances the singlet oxygen photogeneration by prepared composites. The dependence of the intensity of singlet oxygen photogeneration by composites on the power density of exciting radiation (at its variation in the range 0.8 ÷ 1.6 W/cm2) is close to linear. Mn-doped ZnO-ZrO2 composites demonstrate superior antibacterial activity against the gram-positive bacteria Staphylococcus aureus ATCC 209P. It was found that highly dispersed porous Mn-doped ZnO-ZrO2 nanocomposites are promising for practical environmental and medical applications.
{"title":"Effective Photogeneration of Singlet Oxygen and High Photocatalytic and Antibacterial Activities of Porous Mn-Doped ZnO-ZrO2 Nanocomposites","authors":"S. Evstropiev, A. Shelemanov, Igor Bagrov, A. Karavaeva, Kseniya Portnova, N. Nikonorov","doi":"10.21926/cr.2403008","DOIUrl":"https://doi.org/10.21926/cr.2403008","url":null,"abstract":"Disperse porous Mn-doped ZnO-ZrO2 nanocomposites were prepared using the facile polymer-salt method. The effect of Mn content on the crystal structure, composite morphologies, their ability to photogenate the singlet oxygen, luminescence properties, and bactericidal activities were studied. The crystal structure and morphology of these materials were investigated using XRD and SEM analysis. It was found that obtained nanocomposites consist of small (~9 nm) hexagonal ZnO and fine ZrO2 crystals and the embedding of Mn ions expands the crystal cells of ZnO crystals. Photoluminescence spectra indicate the presence of different structural defects (interstitial Zn ions and oxygen vacancies in ZnO and oxygen vacancies in ZrO2 crystals). Mn-doped ZnO-ZrO2 nanocomposites can photogenerate singlet oxygen under visible (λ = 405 nm) irradiation. The increased power density of the exciting blue (λ = 405 nm) light significantly enhances the singlet oxygen photogeneration by prepared composites. The dependence of the intensity of singlet oxygen photogeneration by composites on the power density of exciting radiation (at its variation in the range 0.8 ÷ 1.6 W/cm2) is close to linear. Mn-doped ZnO-ZrO2 composites demonstrate superior antibacterial activity against the gram-positive bacteria Staphylococcus aureus ATCC 209P. It was found that highly dispersed porous Mn-doped ZnO-ZrO2 nanocomposites are promising for practical environmental and medical applications.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"35 S140","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141683363","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}
Sustainability has driven the use of heterogeneous photocatalysis as one of the primary methods for environmental decontamination, reduction, degradation, remediation, or transformation of polluting chemical residues and purification treatment of effluents and wastewater. TiO2 is the most commonly used semiconductor in heterogeneous photocatalysis. It acquires relevance, as it has favorable properties, such as non-toxicity, stability in a wide range of pH, economic viability, etc., which encourage its application as a semiconductor in photocatalytic processes. However, the photocatalytic capabilities of TiO2 are only active in 3% of the solar spectrum, which limits its range of use. For this reason, some semiconductor metal oxides were incorporated into TiO2 to increase its activation range in the UV-visible spectrum. Within this context, WO3 is a metallic oxide widely used in mixtures with TiO2, aiming to improve its photocatalytic properties. Thus, this work synthesized TiO2 and TiO2 nanostructures mixed with two tungsten precursors (H2WO4 and Na2WO4.2H2O) using a microwave-assisted hydrothermal route at 200°C for 120 minutes. The samples obtained were characterized by mL of a 20 ppm solution of methyl orange dye. The results show that it was possible to successfully produce TiO2 and TiO2 nanostructures containing tungsten precursors via a microwave-assisted hydrothermal route. This can be attributed to the fact that the energy associated with this temperature was sufficient to convert most of the precursors into crystalline products and little amorphous phase is present.
{"title":"Determination of Reflectance Spectra and Colorimetry of Titanium and Tungsten Oxides Obtained by Microwave-assisted Hydrothermal Synthesis","authors":"L. Soares, S. Kunst, C. Oliveira, A. K. Alves","doi":"10.21926/cr.2403007","DOIUrl":"https://doi.org/10.21926/cr.2403007","url":null,"abstract":"Sustainability has driven the use of heterogeneous photocatalysis as one of the primary methods for environmental decontamination, reduction, degradation, remediation, or transformation of polluting chemical residues and purification treatment of effluents and wastewater. TiO2 is the most commonly used semiconductor in heterogeneous photocatalysis. It acquires relevance, as it has favorable properties, such as non-toxicity, stability in a wide range of pH, economic viability, etc., which encourage its application as a semiconductor in photocatalytic processes. However, the photocatalytic capabilities of TiO2 are only active in 3% of the solar spectrum, which limits its range of use. For this reason, some semiconductor metal oxides were incorporated into TiO2 to increase its activation range in the UV-visible spectrum. Within this context, WO3 is a metallic oxide widely used in mixtures with TiO2, aiming to improve its photocatalytic properties. Thus, this work synthesized TiO2 and TiO2 nanostructures mixed with two tungsten precursors (H2WO4 and Na2WO4.2H2O) using a microwave-assisted hydrothermal route at 200°C for 120 minutes. The samples obtained were characterized by mL of a 20 ppm solution of methyl orange dye. The results show that it was possible to successfully produce TiO2 and TiO2 nanostructures containing tungsten precursors via a microwave-assisted hydrothermal route. This can be attributed to the fact that the energy associated with this temperature was sufficient to convert most of the precursors into crystalline products and little amorphous phase is present.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"6 13","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-07-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141699257","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}
In this study, by producing bifunctional material, hydrolysis, and supercapacitor applications were investigated. The carbon nanotube-supported Pt catalyst was prepared using the sodium borohydride (NaBH4) reduction. Surface characterization of the synthesized Pt/CNT catalyst was performed using scanning electron microscopy-energy dıstrıbutıon X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Hydrolysis experiments were performed after deciding on the appropriate atomic ratio from the Pt/CNT catalysts synthesized in different nuclear ratios. The parameters affecting the hydrogen production from NaBH4 were examined. As a result of the kinetic calculations, the initial rates of reaction for 30°C and 60°C were calculated as 21949,69 mlH2gcatmin-1 and 70018,18 mlH2gcatmin-1. Galvastonic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used as characterization techniques for the use of Pt/CNT catalysts as electrodes in supercapacitor applications. The specific capacitance value of 7% Pt/CNT catalyst at 1 A/g current density was calculated as 57,78 F/g. Energy and power density were calculated as 8,025 Wh/kg and 963 W/kg, respectively. Therefore, this catalyst is called a “cap-cat” with capacitor properties. The catalyst used in this study is promising for this recently studied topic.
{"title":"A Remarkable Pt Doped CNT Catalyst as a Double Functional Material: Its Application for Hydrogen Production and Supercapacitor","authors":"Tulin Avci Hansu","doi":"10.21926/cr.2402005","DOIUrl":"https://doi.org/10.21926/cr.2402005","url":null,"abstract":"In this study, by producing bifunctional material, hydrolysis, and supercapacitor applications were investigated. The carbon nanotube-supported Pt catalyst was prepared using the sodium borohydride (NaBH4) reduction. Surface characterization of the synthesized Pt/CNT catalyst was performed using scanning electron microscopy-energy dıstrıbutıon X-ray spectrometer (SEM-EDX), X-ray diffraction (XRD), and transmission electron microscopy (TEM). Hydrolysis experiments were performed after deciding on the appropriate atomic ratio from the Pt/CNT catalysts synthesized in different nuclear ratios. The parameters affecting the hydrogen production from NaBH4 were examined. As a result of the kinetic calculations, the initial rates of reaction for 30°C and 60°C were calculated as 21949,69 mlH2gcatmin-1 and 70018,18 mlH2gcatmin-1. Galvastonic charge-discharge (GCD), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) were used as characterization techniques for the use of Pt/CNT catalysts as electrodes in supercapacitor applications. The specific capacitance value of 7% Pt/CNT catalyst at 1 A/g current density was calculated as 57,78 F/g. Energy and power density were calculated as 8,025 Wh/kg and 963 W/kg, respectively. Therefore, this catalyst is called a “cap-cat” with capacitor properties. The catalyst used in this study is promising for this recently studied topic.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"28 3","pages":""},"PeriodicalIF":0.0,"publicationDate":"2024-05-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"140974236","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}
T. R. B. Barros, T. S. B. Barbosa, Meiry Gláucia Freire Rodrigues
This work focuses on preparing NaY zeolite using alternative sources of silica and modifying the zeolite with the surfactant cetyltrimethylammonium bromide. Two different hydrothermal synthesis routes were employed: the conventional method using sodium silicate as the silica source, and the other is a sustainable approach using vermiculite clay as the silica source. In traditional zeolite synthesis, sodium silicate is often used as the source of silica. However, . The vermiculite was subjected to an acid treatment, followed by a primary treatment to obtain silica. Using the ion exchange method, the NaY zeolite was modified by an organic surfactant CTABr. Based on the various characterization techniques, it was possible to verify the obtaining of NaY zeolite through the conventional and sustainable routes, in which the structural properties were maintained. They used the sustainable path to synthesize NaY zeolite, which allowed for obtaining a material with low synthesis cost and properties similar to those synthesized conventionally. The structures of the NaY zeolites were maintained after the modification process with the surfactant Cetyltrimethylammonium Bromide (CTABr), demonstrating the structural stability of the zeolites and the efficiency of the modification process.
{"title":"NaY Zeolite Synthesis from Vermiculite and Modification with Surfactant","authors":"T. R. B. Barros, T. S. B. Barbosa, Meiry Gláucia Freire Rodrigues","doi":"10.21926/cr.2304031","DOIUrl":"https://doi.org/10.21926/cr.2304031","url":null,"abstract":"This work focuses on preparing NaY zeolite using alternative sources of silica and modifying the zeolite with the surfactant cetyltrimethylammonium bromide. Two different hydrothermal synthesis routes were employed: the conventional method using sodium silicate as the silica source, and the other is a sustainable approach using vermiculite clay as the silica source. In traditional zeolite synthesis, sodium silicate is often used as the source of silica. However, . The vermiculite was subjected to an acid treatment, followed by a primary treatment to obtain silica. Using the ion exchange method, the NaY zeolite was modified by an organic surfactant CTABr. Based on the various characterization techniques, it was possible to verify the obtaining of NaY zeolite through the conventional and sustainable routes, in which the structural properties were maintained. They used the sustainable path to synthesize NaY zeolite, which allowed for obtaining a material with low synthesis cost and properties similar to those synthesized conventionally. The structures of the NaY zeolites were maintained after the modification process with the surfactant Cetyltrimethylammonium Bromide (CTABr), demonstrating the structural stability of the zeolites and the efficiency of the modification process.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"49 6","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139155232","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}
The research described the production and characterization of various materials, particularly alpha-alumina ceramic supports, zeolite SAPO-34, and zeolite membranes. Ceramic supports were manufactured through dry uniaxial compaction. Sintering of the supports was carried out at 1300°C for 2 h. SAPO-34 zeolites and zeolite membranes were synthesized through a hydrothermal process involving two steps: a first step at 38°C for 24 h and a second step at 200°C for 24 h. The research aimed to determine how different silica sources, namely Aerosil 380, colloidal silica, and TEOS, influenced the outcome of the synthesis. The study identified that Aerosil 380 silica was the most suitable source for synthesizing SAPO-34 zeolites and membranes. Zeolite membranes (SAPO-34/alpha-alumina) displayed a uniform and homogeneous distribution of SAPO-34 phase zeolitic crystals. The absence of defects or cracks in these membranes confirmed the successful formation of the SAPO-34 zeolite membrane structure. This research has significant implications, particularly in materials science and applications utilizing zeolites and membranes. The choice of silica source plays a crucial role in determining the quality and properties of the synthesized materials, and the detailed characterization provides valuable insights into their performance in practical applications. Overall, the research contributes to the understanding and optimization of zeolite synthesis processes.
{"title":"Synthesis of SAPO-34 Zeolite Membrane: Influence of Sources of Silica","authors":"T. L. Barbosa, M. Rodrigues","doi":"10.21926/cr.2304030","DOIUrl":"https://doi.org/10.21926/cr.2304030","url":null,"abstract":"The research described the production and characterization of various materials, particularly alpha-alumina ceramic supports, zeolite SAPO-34, and zeolite membranes. Ceramic supports were manufactured through dry uniaxial compaction. Sintering of the supports was carried out at 1300°C for 2 h. SAPO-34 zeolites and zeolite membranes were synthesized through a hydrothermal process involving two steps: a first step at 38°C for 24 h and a second step at 200°C for 24 h. The research aimed to determine how different silica sources, namely Aerosil 380, colloidal silica, and TEOS, influenced the outcome of the synthesis. The study identified that Aerosil 380 silica was the most suitable source for synthesizing SAPO-34 zeolites and membranes. Zeolite membranes (SAPO-34/alpha-alumina) displayed a uniform and homogeneous distribution of SAPO-34 phase zeolitic crystals. The absence of defects or cracks in these membranes confirmed the successful formation of the SAPO-34 zeolite membrane structure. This research has significant implications, particularly in materials science and applications utilizing zeolites and membranes. The choice of silica source plays a crucial role in determining the quality and properties of the synthesized materials, and the detailed characterization provides valuable insights into their performance in practical applications. Overall, the research contributes to the understanding and optimization of zeolite synthesis processes.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"26 5","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138980014","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}
Oswaldo Núñez, M. Fereidooni, V. Márquez, Duangthip Sattayamuk, P. Praserthdam, S. Praserthdam
To improve CH4 and H2 formation from CO2 photoreduction using non-organic, non-laborious, and inexpensive photocatalysts, we have prepared two surface-silicate-modified TiO2 catalysts: P25-SiO2 and AmTiO2-SiO2 (amorphous TiO2) to be tested in water and using UV light. The last catalyst produces more CH4 and H2 in water than P25 (3:1 TiO2 anatase: rutile) under UV light irradiation of HCO3- and CO2; am-TiO2-SiO2 at pH = 7, produces 8 times more CH4 and H2 than P25 with selectivity at the reactor headspace of 30% and 53%, respectively. Using CO2 (pH = 3), 80 times more CH4 than P25 under the same conditions is obtained with a yield of 71%. This corresponds to a production of 8.9 μmol gcat-1·h-1, one of the highest reported rates of CH4 production from CO2 using carbon-free semiconductors. H2 is also produced by water splitting using Am-TiO2-SiO2 and water at low pH. The enhanced reactivity compared to P25 is attributed to three main factors: a) Low catalyst PZC (4.1) that facilitates CO2 adsorption and proton availability at the active site to catalyze the e transfer from Ti at the TiO2-SiO2-carbonate adduct b) SiO2 acts as electron trap reducing carriers recombination (External intramolecular trapping (EIT) mechanism) and c) am-TiO2-SiO2, light collection efficiency, surface area and irregular atoms distribution. Catalysts were also tested for Methylene blue (MB) photooxidation. P25 is quite a better catalyst in oxidizing MB via OH radicals, probably due to the more positive valence band potentials in the SiO2-modified catalysts that avoid the OH radical formation from water; however, when bicarbonate is added to MB solution, am-TiO2-SiO2 catalysts reactivity increases as a consequence of its valence band down-bending.
{"title":"In Water High Yield and Selectivity of CH4 and H2 Production Using UVC Light and a SiO2-surface-modified TiO2 Photocatalysts","authors":"Oswaldo Núñez, M. Fereidooni, V. Márquez, Duangthip Sattayamuk, P. Praserthdam, S. Praserthdam","doi":"10.21926/cr.2304029","DOIUrl":"https://doi.org/10.21926/cr.2304029","url":null,"abstract":"To improve CH<sub>4</sub> and H<sub>2</sub> formation from CO<sub>2</sub> photoreduction using non-organic, non-laborious, and inexpensive photocatalysts, we have prepared two surface-silicate-modified TiO<sub>2</sub> catalysts: P25-SiO<sub>2</sub> and AmTiO<sub>2</sub>-SiO<sub>2</sub> (amorphous TiO<sub>2</sub>) to be tested in water and using UV light. The last catalyst produces more CH<sub>4</sub> and H<sub>2</sub> in water than P25 (3:1 TiO<sub>2</sub> anatase: rutile) under UV light irradiation of HCO<sub>3</sub><sup>-</sup> and CO<sub>2</sub>; am-TiO<sub>2</sub>-SiO<sub>2</sub> at pH = 7, produces 8 times more CH<sub>4</sub> and H<sub>2</sub> than P25 with selectivity at the reactor headspace of 30% and 53%, respectively. Using CO<sub>2</sub> (pH = 3), 80 times more CH<sub>4</sub> than P25 under the same conditions is obtained with a yield of 71%. This corresponds to a production of 8.9 μmol g<sub>cat</sub><sup>-1</sup>·h<sup>-1</sup>, one of the highest reported rates of CH<sub>4</sub> production from CO<sub>2</sub> using carbon-free semiconductors. H<sub>2</sub> is also produced by water splitting using Am-TiO<sub>2</sub>-SiO<sub>2</sub> and water at low pH. The enhanced reactivity compared to P25 is attributed to three main factors: a) Low catalyst PZC (4.1) that facilitates CO<sub>2</sub> adsorption and proton availability at the active site to catalyze the e transfer from Ti at the TiO<sub>2</sub>-SiO<sub>2</sub>-carbonate adduct b) SiO<sub>2</sub> acts as electron trap reducing carriers recombination (External intramolecular trapping (EIT) mechanism) and c) am-TiO<sub>2</sub>-SiO<sub>2</sub>, light collection efficiency, surface area and irregular atoms distribution. Catalysts were also tested for Methylene blue (MB) photooxidation. P25 is quite a better catalyst in oxidizing MB via OH radicals, probably due to the more positive valence band potentials in the SiO<sub>2</sub>-modified catalysts that avoid the OH radical formation from water; however, when bicarbonate is added to MB solution, am-TiO<sub>2</sub>-SiO<sub>2</sub> catalysts reactivity increases as a consequence of its valence band down-bending.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"52 8","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"138600750","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 surface modification approach has prepared a nanostructured organic framework connecting two metal oxide NPs. The surface modifier attached two metal oxide NPs via molecular interaction to generate modular structures of fiber, rod, or sponge materials. Thus, obtained hybrid systems have been confirmed through FT-IR, TGA, PXRD, and SEM. Metal oxides such as Fe3O4 and MgO generated mixed materials via the surface modification approach. Thus, obtained materials have been successfully used to dehydrate biomass-derived glucose. The products HMF and subsequently partially oxidized product DFF are considered to be valuable compounds not only in fuel technology but also in the pharmaceutical industry.
{"title":"Nano Metal Oxide Frameworks (NOF): Development of New Heterogeneous Catalyst for the Synthesis of Furan Derivatives from Glucose","authors":"R. Jaiswal, Melad Shaikh, Kalluri V.S. Ranganath","doi":"10.21926/cr.2304028","DOIUrl":"https://doi.org/10.21926/cr.2304028","url":null,"abstract":"A surface modification approach has prepared a nanostructured organic framework connecting two metal oxide NPs. The surface modifier attached two metal oxide NPs via molecular interaction to generate modular structures of fiber, rod, or sponge materials. Thus, obtained hybrid systems have been confirmed through FT-IR, TGA, PXRD, and SEM. Metal oxides such as Fe3O4 and MgO generated mixed materials via the surface modification approach. Thus, obtained materials have been successfully used to dehydrate biomass-derived glucose. The products HMF and subsequently partially oxidized product DFF are considered to be valuable compounds not only in fuel technology but also in the pharmaceutical industry.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"143 ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139250652","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}
Nicolas Ishiki Ishiki/Nicolas, Maria Della-Costa Della-Costa/Maria, Beatriz Keller Keller/Beatriz, Kepler Rocha Rocha/Kepler, Francielle Bortoloti Bortoloti/Francielle, Antonio Angelo Angelo/Antonio
This paper investigates how the aggregation of bimetallic nanoparticles (NPs) influences the electronic condition of the surface adsorption site and, hence, the performance of materials during the electrooxidation of fuels in an alkaline medium. First, we synthesized Pt-Ni NPs in three configurations: ordered intermetallic, ordinary alloy, and core-shell. The NPs contained Pt and Ni close to a 1:1 Pt/Ni atomic ratio. They had similar particle sizes, which allowed us to evaluate their performance without the influence of these physical parameters. Depending on the structural arrangement of the Pt and Ni atoms in the NP, the electronic condition of the surface adsorption site (Pt) changed significantly. Consequently, the performance of the materials varied whenever they were used as anode material for the electrooxidation of hydrogen, methanol, ethanol, ethylene glycol, and glycerol in an alkaline solution. The electronic condition of the surface site strongly affected the adsorption characteristics of the reactants, intermediates, and products, consequently impacting the material's performance during the electrochemical processes. The approach adopted here could contribute to a better understanding of electrocatalytic processes and the design of selective electrocatalysts.
{"title":"Impact of Pt-Ni Nanoparticle Architecture on Electrocatalytic Oxidation Reaction in Fuel Cells","authors":"Nicolas Ishiki Ishiki/Nicolas, Maria Della-Costa Della-Costa/Maria, Beatriz Keller Keller/Beatriz, Kepler Rocha Rocha/Kepler, Francielle Bortoloti Bortoloti/Francielle, Antonio Angelo Angelo/Antonio","doi":"10.21926/cr.2304027","DOIUrl":"https://doi.org/10.21926/cr.2304027","url":null,"abstract":"This paper investigates how the aggregation of bimetallic nanoparticles (NPs) influences the electronic condition of the surface adsorption site and, hence, the performance of materials during the electrooxidation of fuels in an alkaline medium. First, we synthesized Pt-Ni NPs in three configurations: ordered intermetallic, ordinary alloy, and core-shell. The NPs contained Pt and Ni close to a 1:1 Pt/Ni atomic ratio. They had similar particle sizes, which allowed us to evaluate their performance without the influence of these physical parameters. Depending on the structural arrangement of the Pt and Ni atoms in the NP, the electronic condition of the surface adsorption site (Pt) changed significantly. Consequently, the performance of the materials varied whenever they were used as anode material for the electrooxidation of hydrogen, methanol, ethanol, ethylene glycol, and glycerol in an alkaline solution. The electronic condition of the surface site strongly affected the adsorption characteristics of the reactants, intermediates, and products, consequently impacting the material's performance during the electrochemical processes. The approach adopted here could contribute to a better understanding of electrocatalytic processes and the design of selective electrocatalysts.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"13 2","pages":""},"PeriodicalIF":0.0,"publicationDate":"2023-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"139268910","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 will present some sectors in which enzymes can replace traditional catalysts in poly(butylene-succinate) industry, emphasizing the green chemistry aspects associated with these newer strategies.
{"title":"Enzymes in Poly(Butylene-Succinate) Industry: An Overview on Synthesis Routes and Post-Processing Strategies","authors":"Daria Armani, Antonella Petri","doi":"10.21926/cr.2304026","DOIUrl":"https://doi.org/10.21926/cr.2304026","url":null,"abstract":"This paper will present some sectors in which enzymes can replace traditional catalysts in poly(butylene-succinate) industry, emphasizing the green chemistry aspects associated with these newer strategies.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"12 22","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135391492","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}
Tungstophosphate (PW12O403-) intercalated ZnAl-Layered double hydroxide (ZnAl-PW12) was successfully synthesized through the rehydration of calcined LDH. Chemical analyses and characterizations by powder XRD, FT-IR, and Diffuse reflectance UV-Vis spectra confirmed the intercalation of PW12O403- ions equivalent to ~80% of the residual positive charge in the brucite layer. The efficiency of ZnAl-PW12 for decolourisation of four structurally different cationic/anionic dyes through simultaneous adsorption and photocatalysis under visible light irradiation was assessed. Under identical conditions, the photocatalytic efficiency of the ZnAl-PW12 catalyst was found to be much higher than that of calcined ZnAl-LDH, indicating the promoting effect of PW12O403- ion. Moreover, the loss of costly polyoxometallate (POM) could be avoided by intercalating the POM ion in the interlayer of LDH, which can facilitate the use of synthesized catalysts for repeated cycles.
{"title":"Tungstophosphate Intercalated ZnAl Layered Double Hydroxide for Adsorptive and Visible Light Driven Photocatalytic Decolourisation of Organic Dyes","authors":"B. S. Mohanta, Rita Das, N Das","doi":"10.21926/cr.2304025","DOIUrl":"https://doi.org/10.21926/cr.2304025","url":null,"abstract":"Tungstophosphate (PW<sub>12</sub>O<sub>40</sub><sup>3-</sup>) intercalated ZnAl-Layered double hydroxide (ZnAl-PW<sub>12</sub>) was successfully synthesized through the rehydration of calcined LDH. Chemical analyses and characterizations by powder XRD, FT-IR, and Diffuse reflectance UV-Vis spectra confirmed the intercalation of PW<sub>12</sub>O<sub>40</sub><sup>3-</sup> ions equivalent to ~80% of the residual positive charge in the brucite layer. The efficiency of ZnAl-PW<sub>12</sub> for decolourisation of four structurally different cationic/anionic dyes through simultaneous adsorption and photocatalysis under visible light irradiation was assessed. Under identical conditions, the photocatalytic efficiency of the ZnAl-PW<sub>12</sub> catalyst was found to be much higher than that of calcined ZnAl-LDH, indicating the promoting effect of PW<sub>12</sub>O<sub>40</sub><sup>3-</sup> ion. Moreover, the loss of costly polyoxometallate (POM) could be avoided by intercalating the POM ion in the interlayer of LDH, which can facilitate the use of synthesized catalysts for repeated cycles.","PeriodicalId":178524,"journal":{"name":"Catalysis Research","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-10-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135854709","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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