Pub Date : 2025-01-24DOI: 10.1016/j.cattod.2025.115208
Zhongyin Kang , Min Zhang , Yang Wang , Pengtao Yue , Jun Li , Xun Zhu , Qian Fu , Qiang Liao
Acidic electrolysis of CO2 has been considered as a promising route to inhibit carbonate formation, and enhances CO2 utilization efficiency. Suppressing hydrogen evolution reaction (HER) in the excessive H+ environment remains a considerable challenge, however, necessitating concerted efforts toward advanced catalysts and electrode designs to facilitate the CO2 diffusion. Herein, a Ni-N-C catalyst with a hydrophobic property (hydrophobic Ni-N-C) was synthesized as electrocatalyst for CO2 reduction, which showed a high faradaic efficiency of 98.9 % towards CO at 200 mA cm−2 compared to the hydrophilic Ni-N-C catalyst (77.8 %). Remarkably, when integrated into a gas diffusion electrode (GDE) in a flow cell, the hydrophobic Ni-N-C was capable of delivering carbon utilization up to 82.8 %, surpassing all of the other CO2 reduction electrocatalysts in alkaline electrolysis in the literature. Such outstanding performance could be contributed to the hydrophobic Ni-N-C with multiple three-phase interface, which provided superior gas-phase transfer channels for CO2 supply and impeded the H+-enriched on the catalyst surface, thus successfully suppressing the HER during the acidic CO2 electrolysis. This work may inspire further optimization of the wettability of catalyst electrode for electrochemical CO2 reduction and other gas consumption electrosynthesis in acidic electrolysis.
{"title":"Regulating CO2/H2O ratio of Ni-N-C single-atom catalysts through hydrophobicity engineering for acidic CO2 electroreduction","authors":"Zhongyin Kang , Min Zhang , Yang Wang , Pengtao Yue , Jun Li , Xun Zhu , Qian Fu , Qiang Liao","doi":"10.1016/j.cattod.2025.115208","DOIUrl":"10.1016/j.cattod.2025.115208","url":null,"abstract":"<div><div>Acidic electrolysis of CO<sub>2</sub> has been considered as a promising route to inhibit carbonate formation, and enhances CO<sub>2</sub> utilization efficiency. Suppressing hydrogen evolution reaction (HER) in the excessive H<sup>+</sup> environment remains a considerable challenge, however, necessitating concerted efforts toward advanced catalysts and electrode designs to facilitate the CO<sub>2</sub> diffusion. Herein, a Ni-N-C catalyst with a hydrophobic property (hydrophobic Ni-N-C) was synthesized as electrocatalyst for CO<sub>2</sub> reduction, which showed a high faradaic efficiency of 98.9 % towards CO at 200 mA cm<sup>−2</sup> compared to the hydrophilic Ni-N-C catalyst (77.8 %). Remarkably, when integrated into a gas diffusion electrode (GDE) in a flow cell, the hydrophobic Ni-N-C was capable of delivering carbon utilization up to 82.8 %, surpassing all of the other CO<sub>2</sub> reduction electrocatalysts in alkaline electrolysis in the literature. Such outstanding performance could be contributed to the hydrophobic Ni-N-C with multiple three-phase interface, which provided superior gas-phase transfer channels for CO<sub>2</sub> supply and impeded the H<sup>+</sup>-enriched on the catalyst surface, thus successfully suppressing the HER during the acidic CO<sub>2</sub> electrolysis. This work may inspire further optimization of the wettability of catalyst electrode for electrochemical CO<sub>2</sub> reduction and other gas consumption electrosynthesis in acidic electrolysis.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115208"},"PeriodicalIF":5.2,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-23DOI: 10.1016/j.cattod.2025.115211
Natalia Uricochea , Victor Uzquiano , Marta Paniagua , Gabriel Morales , Juan A. Melero
The high potential of using levulinic acid and furfural as platform molecules for the production of oxygenated adducts suitable as precursors for SAF synthesis is studied through the aldol condensation of both molecules. The research is the first-time demonstration of solventless acid-catalysed levulinic acid/furfural aldol condensation. The catalytic performance of a commercial H-USY zeolite and two post-synthetic variations thereof, with different dealumination degree and Zr loading, is analyzed, aiming at tuning the acid catalytic properties. The catalyst with an almost complete Al removal accompanied by the highest Zr wt% (Zr-USY-2) gave the best results in terms of selective conversion of furfural, pointing out to the Lewis acid sites as the main active sites to promote the aldol condensation reaction. An experimental design allowed to identify the optimal LA/FAL molar ratio (9/1) and reaction temperature (140 °C), while catalyst loading presented a minor significance. The optimization of the reaction parameters allowed to achieve a maximum furfural conversion of 88 %, combined with a yield towards the desired C10 adducts of 55 %. Furthermore, despite the catalytic performance of this material is slightly impaired in consecutive reaction cycles, it can be recovered with a thermal regeneration step, indicating a good reusability.
{"title":"Zr-modified USY zeolite as an efficient catalyst for the production of bio-jet fuel precursors from levulinic acid and furfural in the absence of solvent","authors":"Natalia Uricochea , Victor Uzquiano , Marta Paniagua , Gabriel Morales , Juan A. Melero","doi":"10.1016/j.cattod.2025.115211","DOIUrl":"10.1016/j.cattod.2025.115211","url":null,"abstract":"<div><div>The high potential of using levulinic acid and furfural as platform molecules for the production of oxygenated adducts suitable as precursors for SAF synthesis is studied through the aldol condensation of both molecules. The research is the first-time demonstration of solventless acid-catalysed levulinic acid/furfural aldol condensation. The catalytic performance of a commercial H-USY zeolite and two post-synthetic variations thereof, with different dealumination degree and Zr loading, is analyzed, aiming at tuning the acid catalytic properties. The catalyst with an almost complete Al removal accompanied by the highest Zr wt% (Zr-USY-2) gave the best results in terms of selective conversion of furfural, pointing out to the Lewis acid sites as the main active sites to promote the aldol condensation reaction. An experimental design allowed to identify the optimal LA/FAL molar ratio (9/1) and reaction temperature (140 °C), while catalyst loading presented a minor significance. The optimization of the reaction parameters allowed to achieve a maximum furfural conversion of 88 %, combined with a yield towards the desired C10 adducts of 55 %. Furthermore, despite the catalytic performance of this material is slightly impaired in consecutive reaction cycles, it can be recovered with a thermal regeneration step, indicating a good reusability.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115211"},"PeriodicalIF":5.2,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173707","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-21DOI: 10.1016/j.cattod.2025.115209
Arisha Sharma, Prakash Biswas
Methane tri-reforming (MTR) is a promising approach for the utilization of anthropogenic greenhouse gases such as CH4 and CO2 to produce syngas. In this work, the activities of monometallic (Ru, Ni) and bimetallic (Ru-Ni) catalysts supported on the alumina derived from metal-organic framework (MOF) precursors were compared for MTR. The catalysts were synthesized by impregnation technique, and their activity was investigated in a packed bed-down flow tubular reactor over a temperature range of 600–800 °C at 1 atm. The catalyst structure-activity relationship was determined with the help of extensive catalyst characterization techniques, including N2 physisorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), and CO2 temperature-programmed desorption (CO2-TPD). Experimental results demonstrated that the bimetallic catalyst was more active as compared to monometallic one. Among the bimetallic catalysts, 0.65RuNAlM-53 catalyst demonstrated comparatively high CO2 conversion (36.1 %) and an almost complete conversion of CH4 (99.9 %) with an H2/CO ratio of 3.2 at 800 °C. The 0.65RuNAlM-53 catalyst showed consistent activity for a prolonged duration of > 125 h with no carbon deposition. Based on the experimental observation, a probable reaction mechanism is proposed for the MTR. The catalyst structure was intact even after 125 h of reaction, which suggested the MOF-derived Ru-Ni bimetallic catalyst developed is very promising for MTR.
{"title":"Methane tri-reforming over Ni, Ru monometallic and Ni-Ru bimetallic catalyst supported on MIL-53 metal-organic framework","authors":"Arisha Sharma, Prakash Biswas","doi":"10.1016/j.cattod.2025.115209","DOIUrl":"10.1016/j.cattod.2025.115209","url":null,"abstract":"<div><div>Methane tri-reforming (MTR) is a promising approach for the utilization of anthropogenic greenhouse gases such as CH<sub>4</sub> and CO<sub>2</sub> to produce syngas. In this work, the activities of monometallic (Ru, Ni) and bimetallic (Ru-Ni) catalysts supported on the alumina derived from metal-organic framework (MOF) precursors were compared for MTR. The catalysts were synthesized by impregnation technique, and their activity was investigated in a packed bed-down flow tubular reactor over a temperature range of 600–800 °C at 1 atm. The catalyst structure-activity relationship was determined with the help of extensive catalyst characterization techniques, including N<sub>2</sub> physisorption, X-ray diffraction (XRD), temperature-programmed reduction (TPR), and CO<sub>2</sub> temperature-programmed desorption (CO<sub>2</sub>-TPD). Experimental results demonstrated that the bimetallic catalyst was more active as compared to monometallic one. Among the bimetallic catalysts, 0.65RuNAl<sub>M-53</sub> catalyst demonstrated comparatively high CO<sub>2</sub> conversion (36.1 %) and an almost complete conversion of CH<sub>4</sub> (99.9 %) with an H<sub>2</sub>/CO ratio of 3.2 at 800 °C. The 0.65RuNAl<sub>M-53</sub> catalyst showed consistent activity for a prolonged duration of > 125 h with no carbon deposition. Based on the experimental observation, a probable reaction mechanism is proposed for the MTR. The catalyst structure was intact even after 125 h of reaction, which suggested the MOF-derived Ru-Ni bimetallic catalyst developed is very promising for MTR.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115209"},"PeriodicalIF":5.2,"publicationDate":"2025-01-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173705","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-18DOI: 10.1016/j.cattod.2025.115201
Houssam-Eddine Nemamcha , Nhu-Nang Vu , Jaspal Singh , Dinh Son Tran , Cédrik Boisvert , Phuong Nguyen-Tri
Novel Carbon nanospheres@graphitic-carbon nitride nanocomposites were successfully synthesized by a simple, inexpensive and ecofriendly chemical method (hydrothermal). The as-prepared materials Carbon nanospheres (CNS), pure g-C3N4, CNS@g-C3N4 and heat treated (HT)CNS@g-C3N4 were characterized by FTIR, Raman spectroscopy, XPS, XRD, TEM, EDX and N2-adsorption desorption, UV-Visible DRS, and Photoluminescence (PL). The photodegradation of bisphenol A (a typical endocrine disruptor) using photocatalysts was followed by HPLC-UV technique. The results show that (HT)CNS@g-C3N4 exhibits high photocatalytic efficiency for BPA degradation (99 %), which is 45 and 8.5 times greater than that of pure g-C3N4 and CNS@g-C3N4, respectively. Additionally, the (HT)CNS@g-C3N4 photocatalyst displays a high constant rate of apparent pseudo-first-order (kapp = 94.78 × 10−3 min–1) and low electrical energy per order consumption (EEO = 0.24 kWh/m3). These excellent abilities of (HT)CNS@g-C3N4 were attributed to its excellent morphological, structural and optical properties induced during the heat treatment: (i) The presence of CNS reduces the bad gap and consequently enhances the absorption of visible light and promotes the charge carriers separation, (ii) the high specific surface area and porosity and therefore availability of a high number of active sites to interact with BPA, (iii) high presence of different functional groups on the catalyst surface that enhance the interaction between the surface and BPA molecules, and (iv) The heterojunction interface created between CNS and g-C3N4 constitutes an efficient structure that enhances interfacial charge transfer and prevents direct recombination of charge carriers originating from g-C3N4. Based on the identification of the products and intermediates of the BPA photodegradation reaction, by HPLC−MS, a plausible mechanism of photocatalytic degradation of BPA using the prepared photocatalysts was proposed.
{"title":"Facile green synthesis of highly efficient carbon nanospheres@g-C3N4 catalysts for photodegradation of Bisphenol A","authors":"Houssam-Eddine Nemamcha , Nhu-Nang Vu , Jaspal Singh , Dinh Son Tran , Cédrik Boisvert , Phuong Nguyen-Tri","doi":"10.1016/j.cattod.2025.115201","DOIUrl":"10.1016/j.cattod.2025.115201","url":null,"abstract":"<div><div>Novel Carbon nanospheres@graphitic-carbon nitride nanocomposites were successfully synthesized by a simple, inexpensive and ecofriendly chemical method (hydrothermal). The as-prepared materials Carbon nanospheres (CNS), pure g-C<sub>3</sub>N<sub>4</sub>, CNS@g-C<sub>3</sub>N<sub>4</sub> and heat treated (HT)CNS@g-C<sub>3</sub>N<sub>4</sub> were characterized by FTIR, Raman spectroscopy, XPS, XRD, TEM, EDX and N<sub>2</sub>-adsorption desorption, UV-Visible DRS, and Photoluminescence (PL). The photodegradation of bisphenol A (a typical endocrine disruptor) using photocatalysts was followed by HPLC-UV technique. The results show that (HT)CNS@g-C<sub>3</sub>N<sub>4</sub> exhibits high photocatalytic efficiency for BPA degradation (99 %), which is 45 and 8.5 times greater than that of pure g-C<sub>3</sub>N<sub>4</sub> and CNS@g-C<sub>3</sub>N<sub>4</sub>, respectively. Additionally, the (HT)CNS@g-C<sub>3</sub>N<sub>4</sub> photocatalyst displays a high constant rate of apparent pseudo-first-order (k<sub>app</sub> = 94.78 × 10<sup>−3</sup> min<sup>–1</sup>) and low electrical energy per order consumption (EEO = 0.24 kWh/m<sup>3</sup>). These excellent abilities of (HT)CNS@g-C<sub>3</sub>N<sub>4</sub> were attributed to its excellent morphological, structural and optical properties induced during the heat treatment: (<em>i</em>) The presence of CNS reduces the bad gap and consequently enhances the absorption of visible light and promotes the charge carriers separation, <em>(ii)</em> the high specific surface area and porosity and therefore availability of a high number of active sites to interact with BPA, (<em>iii</em>) high presence of different functional groups on the catalyst surface that enhance the interaction between the surface and BPA molecules, and (<em>iv</em>) The heterojunction interface created between CNS and g-C<sub>3</sub>N<sub>4</sub> constitutes an efficient structure that enhances interfacial charge transfer and prevents direct recombination of charge carriers originating from g-C<sub>3</sub>N<sub>4</sub>. Based on the identification of the products and intermediates of the BPA photodegradation reaction, by HPLC−MS, a plausible mechanism of photocatalytic degradation of BPA using the prepared photocatalysts was proposed.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115201"},"PeriodicalIF":5.2,"publicationDate":"2025-01-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173706","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-17DOI: 10.1016/j.cattod.2025.115205
Alessandro Pietro Tucci , Sapia Murgolo , Cristina De Ceglie , Giuseppe Mascolo , Massimo Carmagnani , Paolo Ronco , Massimiliano Bestetti , Silvia Franz
Photoelectrocatalysis (PEC) was applied for the degradation of PFASs in natural groundwater collected from two wells located in the Veneto Region (Italy) where a massive contamination of the aquifer was discovered. Out of 48 monitored species, up to 9 PFASs were detected. On average, the degradation rate followed the order: PFOA>PFHpA>PFHxA≈PFPeA>PFBA and PFOS>PFHpS; the concentration of PFBS and PFHxS did not change during the tests. The overall PFASs concentration decreased by 63 % in well 1 and by 65 % in well 2. PEC tests of PFOA solutions ([PFOA] = 2 μg/l; [K2SO4] = 4 mM] induced the transient formation of PFHpA, followed by PFHxA, PFPeA and PFBA, confirming the reaction pathway consisting of decarboxylation followed by a stepwise losing of CF2 units, transiently forming shorter chain intermediates. PEC efficiency was compared to photolysis. According to electrical energy per order of magnitude, PEC outperforms conventional photolysis and most of the other advanced oxidation processes reported in literature.
{"title":"Photoelectrocatalytic advanced oxidation of perfluoroalkyl substances in groundwaters of the Veneto Region, Italy","authors":"Alessandro Pietro Tucci , Sapia Murgolo , Cristina De Ceglie , Giuseppe Mascolo , Massimo Carmagnani , Paolo Ronco , Massimiliano Bestetti , Silvia Franz","doi":"10.1016/j.cattod.2025.115205","DOIUrl":"10.1016/j.cattod.2025.115205","url":null,"abstract":"<div><div>Photoelectrocatalysis (PEC) was applied for the degradation of PFASs in natural groundwater collected from two wells located in the Veneto Region (Italy) where a massive contamination of the aquifer was discovered. Out of 48 monitored species, up to 9 PFASs were detected. On average, the degradation rate followed the order: PFOA>PFHpA>PFHxA≈PFPeA>PFBA and PFOS>PFHpS; the concentration of PFBS and PFHxS did not change during the tests. The overall PFASs concentration decreased by 63 % in well 1 and by 65 % in well 2. PEC tests of PFOA solutions ([PFOA] = 2 μg/l; [K<sub><em>2</em></sub>SO<sub>4</sub>] = 4 mM] induced the transient formation of PFHpA, followed by PFHxA, PFPeA and PFBA, confirming the reaction pathway consisting of decarboxylation followed by a stepwise losing of CF<sub>2</sub> units, transiently forming shorter chain intermediates. PEC efficiency was compared to photolysis. According to electrical energy per order of magnitude, PEC outperforms conventional photolysis and most of the other advanced oxidation processes reported in literature.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115205"},"PeriodicalIF":5.2,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172956","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-16DOI: 10.1016/j.cattod.2025.115206
T. Imrich , T. Nakata , T. Ohno , J. Krýsa
In contrast to the industrial-scale production of H2O2, electrochemical or photoelectrochemical synthesis is an environmentally friendly alternative. In this study, the photoelectrochemical generation of H2O2 was investigated using a hematite (α-Fe2O3/FTO/glass) photoanode in combination with a gas diffusion electrode (GDE) modified by the incorporation of tin(II) phthalocyanine (SnPc) in its hydrophilic layer. The experiments were conducted in a photoelectrochemical cell with two compartments separated by a proton exchange membrane, under an applied bias and AM1.5 irradiation (100 mW/cm2). The amount of H2O2 generated was quantified through chemical analysis using visible light spectrophotometry of the electrolyte. To assess the process efficiency, the Faradaic efficiency (FE) was calculated. The optimal configuration employed air as the inlet gas for the GDE and phosphate buffer (pH 6.4) as the electrolyte in the cathodic compartment. The combination of the hematite photoanode and the GDE modified with SnPc was the most effective for H2O2 photoelectrochemical generation. The highest FE values achieved were 52.4 % for the GDE (O2 reduction to H2O2) and 0.4 % for the hematite photoanode (H2O oxidation to H2O2).
{"title":"Photoelectrochemical generation of H2O2 using hematite (α-Fe2O3) and gas diffusion electrode (GDE)","authors":"T. Imrich , T. Nakata , T. Ohno , J. Krýsa","doi":"10.1016/j.cattod.2025.115206","DOIUrl":"10.1016/j.cattod.2025.115206","url":null,"abstract":"<div><div>In contrast to the industrial-scale production of H<sub>2</sub>O<sub>2</sub>, electrochemical or photoelectrochemical synthesis is an environmentally friendly alternative. In this study, the photoelectrochemical generation of H<sub>2</sub>O<sub>2</sub> was investigated using a hematite (α-Fe<sub>2</sub>O<sub>3</sub>/FTO/glass) photoanode in combination with a gas diffusion electrode (GDE) modified by the incorporation of tin(II) phthalocyanine (SnPc) in its hydrophilic layer. The experiments were conducted in a photoelectrochemical cell with two compartments separated by a proton exchange membrane, under an applied bias and AM1.5 irradiation (100 mW/cm<sup>2</sup>). The amount of H<sub>2</sub>O<sub>2</sub> generated was quantified through chemical analysis using visible light spectrophotometry of the electrolyte. To assess the process efficiency, the Faradaic efficiency (<em>FE</em>) was calculated. The optimal configuration employed air as the inlet gas for the GDE and phosphate buffer (pH 6.4) as the electrolyte in the cathodic compartment. The combination of the hematite photoanode and the GDE modified with SnPc was the most effective for H<sub>2</sub>O<sub>2</sub> photoelectrochemical generation. The highest <em>FE</em> values achieved were 52.4 % for the GDE (O<sub>2</sub> reduction to H<sub>2</sub>O<sub>2</sub>) and 0.4 % for the hematite photoanode (H<sub>2</sub>O oxidation to H<sub>2</sub>O<sub>2</sub>).</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115206"},"PeriodicalIF":5.2,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143173703","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-16DOI: 10.1016/j.cattod.2025.115204
Peter Nadrah , Mateja Knap , Tatiparthi Vikram Sagar , Andrijana Sever Škapin , Urška Lavrenčič Štangar
To investigate the influence of different CeO2 precursors and Ce:Ti ratios, we have synthesised 8 mesoporous Ti-Ce oxides via the evaporation-induced self-assembly (EISA) method with Ce:Ti ratios between 0.2 and 20 mol%. The materials exhibited type IV isotherms and a specific surface area of 140–180 m2·g−1 with pore diameters in range of 3–20 nm. The crystalline phases of materials comprised predominantly anatase with a significant decrease in overall crystalline content with increasing Ce:Ti ratio. Materials with higher Ce:Ti ratio showed an increased light absorption in the visible region. Although crystalline CeO2 was not detected, the presence of Ce(IV) was confirmed by X-ray photoelectron spectroscopy. For the photocatalytic experiments, we compared these materials with the TiO2-CeO2 composites of our previously published syntheses to yield 16 samples synthesized via three synthesis approaches: (1) concurrent synthesis from titanium alkoxide and cerium salts in one pot, (2) synthesis of TiO2 in the presence of previously-synthesised CeO2 and (3) physical mixing of separately-synthesised TiO2 and CeO2. Samples produced by physically mixing the separately-synthesised TiO2 and CeO2 showed the best photocatalytic activity towards gaseous isopropanol degradation, while the samples with TiO2 synthesised in the presence of CeO2 showed the best photocatalytic stability.
{"title":"Effect of Ce:Ti ratio and cerium salts on the properties of mesoporous Ti-Ce oxides and their photocatalytic activity","authors":"Peter Nadrah , Mateja Knap , Tatiparthi Vikram Sagar , Andrijana Sever Škapin , Urška Lavrenčič Štangar","doi":"10.1016/j.cattod.2025.115204","DOIUrl":"10.1016/j.cattod.2025.115204","url":null,"abstract":"<div><div>To investigate the influence of different CeO<sub>2</sub> precursors and Ce:Ti ratios, we have synthesised 8 mesoporous Ti-Ce oxides via the evaporation-induced self-assembly (EISA) method with Ce:Ti ratios between 0.2 and 20 mol%. The materials exhibited type IV isotherms and a specific surface area of 140–180 m<sup>2</sup>·g<sup>−</sup><sup>1</sup> with pore diameters in range of 3–20 nm. The crystalline phases of materials comprised predominantly anatase with a significant decrease in overall crystalline content with increasing Ce:Ti ratio. Materials with higher Ce:Ti ratio showed an increased light absorption in the visible region. Although crystalline CeO<sub>2</sub> was not detected, the presence of Ce(IV) was confirmed by X-ray photoelectron spectroscopy. For the photocatalytic experiments, we compared these materials with the TiO<sub>2</sub>-CeO<sub>2</sub> composites of our previously published syntheses to yield 16 samples synthesized via three synthesis approaches: (1) concurrent synthesis from titanium alkoxide and cerium salts in one pot, (2) synthesis of TiO<sub>2</sub> in the presence of previously-synthesised CeO<sub>2</sub> and (3) physical mixing of separately-synthesised TiO<sub>2</sub> and CeO<sub>2</sub>. Samples produced by physically mixing the separately-synthesised TiO<sub>2</sub> and CeO<sub>2</sub> showed the best photocatalytic activity towards gaseous isopropanol degradation, while the samples with TiO<sub>2</sub> synthesised in the presence of CeO<sub>2</sub> showed the best photocatalytic stability.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"449 ","pages":"Article 115204"},"PeriodicalIF":5.2,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143097918","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The dioxirane epoxidation was traditionally carried out in a two-phase medium: an organic solvent to dilute the olefin to be epoxidised and an aqueous medium in which the peroxymonosulphate oxidant is dissolved. This phase incompatibility generally requires a large quantity of oxidant and oxygen yield does not exceed 25 %. Despite the major advantages of this technique, it is still only used at laboratory scale. The aim of this study is to illustrate a dioxirane epoxidation ability to produce terpene epoxides at the scale of hundreds of milliliters. The technique employs an acetone catalyst that reacts with oxone® to in-situ form dimethyldioxirane, which epoxidizes the terpene. Oxone® is an aqueous oxidant. To remedy its incompatibility with hydrophobic terpene the use of a surfactant at concentration above its critical micelle concentration (cmc) enabled the terpene to be highly dispersed in the aqueous medium in absence of any additional organic solvent by forming a microemulsion, thus improving interface reaction rate and reducing oxygen loss. At 25°C and for a tr of 90 min, several hundred milliliters of limonene, α-pinene, β-pinene, α-terpinene, γ-terpinene, β-myrcene and farnesene were easily epoxidized with both conversion and selectivity of almost 100 %. Oxygen yields of up to 80 % were achieved, against 29 % in absence of microemulsion. The high selectivity of epoxides, the solvent-free aqueous reaction, the ambient conditions, the simple acetone used as catalyst and the easy separation of epoxides from the aqueous medium make this innovative process more appropriate for easy scale-up.
{"title":"Scaled up epoxidation of terpenes in microemulsion","authors":"Yacoub Mahamat Ahmat, Hilaire Mossak Kamkui, Serge Kaliaguine","doi":"10.1016/j.cattod.2025.115202","DOIUrl":"10.1016/j.cattod.2025.115202","url":null,"abstract":"<div><div>The dioxirane epoxidation was traditionally carried out in a two-phase medium: an organic solvent to dilute the olefin to be epoxidised and an aqueous medium in which the peroxymonosulphate oxidant is dissolved. This phase incompatibility generally requires a large quantity of oxidant and oxygen yield does not exceed 25 %. Despite the major advantages of this technique, it is still only used at laboratory scale. The aim of this study is to illustrate a dioxirane epoxidation ability to produce terpene epoxides at the scale of hundreds of milliliters. The technique employs an acetone catalyst that reacts with oxone® to in-situ form dimethyldioxirane, which epoxidizes the terpene. Oxone® is an aqueous oxidant. To remedy its incompatibility with hydrophobic terpene the use of a surfactant at concentration above its critical micelle concentration (cmc) enabled the terpene to be highly dispersed in the aqueous medium in absence of any additional organic solvent by forming a microemulsion, thus improving interface reaction rate and reducing oxygen loss. At 25°C and for a t<sub>r</sub> of 90 min, several hundred milliliters of limonene, α-pinene, β-pinene, α-terpinene, γ-terpinene, β-myrcene and farnesene were easily epoxidized with both conversion and selectivity of almost 100 %. Oxygen yields of up to 80 % were achieved, against 29 % in absence of microemulsion. The high selectivity of epoxides, the solvent-free aqueous reaction, the ambient conditions, the simple acetone used as catalyst and the easy separation of epoxides from the aqueous medium make this innovative process more appropriate for easy scale-up.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"449 ","pages":"Article 115202"},"PeriodicalIF":5.2,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141083","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-14DOI: 10.1016/j.cattod.2025.115198
J.C. Castillo-Rodríguez , M.P. Marco-Buj , J. Giménez , F.J. Tzompantzi-Morales , C. Tzompantzi-Flores , C. Sans-Mazón
In the present study, materials based on hydrochar modified with hydrozincite were designed, varying the weight percentage of hydrozincite. The hydrozincite was prepared via a chemical co-precipitation method using thermal urea hydrolysis without any prior activation or calcination process. The hydrochar modified with hydrozincite was synthesized using a hydrothermal method at 300°C. These materials were applied in the photodegradation of contaminants. The characterization of these materials revealed that the presence of heterojunctions and oxygen vacancies plays a crucial role in the photocatalytic reaction mechanism. These materials were evaluated under UV light and a solar light simulator. The material that exhibited the highest photodegradation percentage contained 10 % by weight of hydrozincite. This suggests that these materials could be a promising alternative for the decomposition of such pollutants present in wastewater.
{"title":"Novel hydrochar-modified hydrozincite designed and applied for the efficient degradation of pollutants in wastewater treatment","authors":"J.C. Castillo-Rodríguez , M.P. Marco-Buj , J. Giménez , F.J. Tzompantzi-Morales , C. Tzompantzi-Flores , C. Sans-Mazón","doi":"10.1016/j.cattod.2025.115198","DOIUrl":"10.1016/j.cattod.2025.115198","url":null,"abstract":"<div><div>In the present study, materials based on hydrochar modified with hydrozincite were designed, varying the weight percentage of hydrozincite. The hydrozincite was prepared via a chemical co-precipitation method using thermal urea hydrolysis without any prior activation or calcination process. The hydrochar modified with hydrozincite was synthesized using a hydrothermal method at 300°C. These materials were applied in the photodegradation of contaminants. The characterization of these materials revealed that the presence of heterojunctions and oxygen vacancies plays a crucial role in the photocatalytic reaction mechanism. These materials were evaluated under UV light and a solar light simulator. The material that exhibited the highest photodegradation percentage contained 10 % by weight of hydrozincite. This suggests that these materials could be a promising alternative for the decomposition of such pollutants present in wastewater.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"449 ","pages":"Article 115198"},"PeriodicalIF":5.2,"publicationDate":"2025-01-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143141078","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2025-01-13DOI: 10.1016/j.cattod.2025.115187
Fahimeh Forouzeshfar , M.R. Coleman , Joseph G. Lawrence
This research investigated depolymerization of poly (ethylene terephthalate) (PET) via glycolysis using a series of ionic liquid (IL) catalysts. Organic acids were paired with 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU) to produce ionic liquids (DBU-ILs). The study explored the effect of structural variations in the organic acids on PET conversion and bis (2-hydroxyethyl) terephthalate (BHET) yield under optimized reaction conditions (specifically, EG:PET ratio of 5:1, temperature of 190 °C, reaction time of 120 min, and 5 mol% DBU in the catalyst relative to PET). The organic acids were selected to include variation in the (i) number of carboxylic acids available to complex with DBU and (ii) structure of the linker and pendant groups to adjust the lipophilicity of the catalyst. The catalytic activity of the DBU-IL increased with increasing lipophilicity of organic acid. Catalysts with organic acids with aromatic linkers (i.e. terephthalic acid) exhibited lower activities than aliphatic linkers at similar lipophilicity. Notably, a linear relationship was observed between the catalytic activity and lipophilicity for diacids with aliphatic linker of increasing chain length. The apparent rate constant for the DBU-azelaic acid was 32 % greater than for DBU-oxalic acid. Reusability studies showed that there was minimal degradation of the catalytic activity of the DBU-ILs over five reaction cycles.
{"title":"Glycolysis of poly (ethylene terephthalate) using DBU-based ionic liquid catalysts","authors":"Fahimeh Forouzeshfar , M.R. Coleman , Joseph G. Lawrence","doi":"10.1016/j.cattod.2025.115187","DOIUrl":"10.1016/j.cattod.2025.115187","url":null,"abstract":"<div><div>This research investigated depolymerization of poly (ethylene terephthalate) (PET) via glycolysis using a series of ionic liquid (IL) catalysts. Organic acids were paired with 1,8-Diazabicyclo [5.4.0] undec-7-ene (DBU) to produce ionic liquids (DBU-ILs). The study explored the effect of structural variations in the organic acids on PET conversion and bis (2-hydroxyethyl) terephthalate (BHET) yield under optimized reaction conditions (specifically, EG:PET ratio of 5:1, temperature of 190 °C, reaction time of 120 min, and 5 mol% DBU in the catalyst relative to PET). The organic acids were selected to include variation in the (i) number of carboxylic acids available to complex with DBU and (ii) structure of the linker and pendant groups to adjust the lipophilicity of the catalyst. The catalytic activity of the DBU-IL increased with increasing lipophilicity of organic acid. Catalysts with organic acids with aromatic linkers (i.e. terephthalic acid) exhibited lower activities than aliphatic linkers at similar lipophilicity. Notably, a linear relationship was observed between the catalytic activity and lipophilicity for diacids with aliphatic linker of increasing chain length. The apparent rate constant for the DBU-azelaic acid was 32 % greater than for DBU-oxalic acid. Reusability studies showed that there was minimal degradation of the catalytic activity of the DBU-ILs over five reaction cycles.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"450 ","pages":"Article 115187"},"PeriodicalIF":5.2,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143172527","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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