Pub Date : 2025-10-14DOI: 10.1016/j.cattod.2025.115611
Wojciech Patkowski , Magdalena Zybert , Urszula Ulkowska , Hubert Ronduda , Weronika Bulejak , Małgorzata Lemańska , Aleksander Albrecht , Dariusz Moszyński , Aleksandra Fidler , Piotr Dłużewski , Wioletta Raróg-Pilecka
Developing efficient ammonia synthesis catalysts is key to reducing energy consumption and improving sustainability. This study explores barium-promoted cobalt catalysts supported on lanthanide oxides (La2O3, Nd2O3, Sm2O3, Eu2O3, Gd2O3) to understand how support choice influences catalytic performance. The catalysts were characterised using techniques such as X-ray powder diffraction (XRPD), high-resolution transmission electron microscopy (HRTEM), and temperature-programmed desorption (H2-TPD, CO2-TPD). Testing under industrially relevant conditions (400–470°C, 6.3 MPa, H2/N2 = 3) revealed that lanthanide oxides strongly affect catalysts' activity, reducibility, and hydrogen adsorption. Among the tested catalysts, the La2O3-supported system exhibited the highest ammonia synthesis activity (), likely due to its favorable hydrogen sorption properties and larger active phase surface area available for hydrogen (31 m²·gCo⁻¹). These findings highlight the potential of lanthanide oxides as supports and the importance of barium as a promoter in cobalt-based catalysts for ammonia synthesis.
{"title":"Influence of lanthanide oxide supports on the performance of barium-promoted cobalt catalysts for ammonia synthesis","authors":"Wojciech Patkowski , Magdalena Zybert , Urszula Ulkowska , Hubert Ronduda , Weronika Bulejak , Małgorzata Lemańska , Aleksander Albrecht , Dariusz Moszyński , Aleksandra Fidler , Piotr Dłużewski , Wioletta Raróg-Pilecka","doi":"10.1016/j.cattod.2025.115611","DOIUrl":"10.1016/j.cattod.2025.115611","url":null,"abstract":"<div><div>Developing efficient ammonia synthesis catalysts is key to reducing energy consumption and improving sustainability. This study explores barium-promoted cobalt catalysts supported on lanthanide oxides (La<sub>2</sub>O<sub>3</sub>, Nd<sub>2</sub>O<sub>3</sub>, Sm<sub>2</sub>O<sub>3</sub>, Eu<sub>2</sub>O<sub>3</sub>, Gd<sub>2</sub>O<sub>3</sub>) to understand how support choice influences catalytic performance. The catalysts were characterised using techniques such as X-ray powder diffraction (XRPD), high-resolution transmission electron microscopy (HRTEM), and temperature-programmed desorption (H<sub>2</sub>-TPD, CO<sub>2</sub>-TPD). Testing under industrially relevant conditions (400–470°C, 6.3 MPa, H<sub>2</sub>/N<sub>2</sub> = 3) revealed that lanthanide oxides strongly affect catalysts' activity, reducibility, and hydrogen adsorption. Among the tested catalysts, the La<sub>2</sub>O<sub>3</sub>-supported system exhibited the highest ammonia synthesis activity (<span><math><mrow><msub><mrow><mi>r</mi></mrow><mrow><mi>avg</mi></mrow></msub><mo>=</mo><mn>1.90</mn><msub><mi>g</mi><mrow><mi>N</mi><msub><mi>H</mi><mn>3</mn></msub></mrow></msub><mo>∙</mo><msubsup><mi>g</mi><mi>cat</mi><mrow><mo>−</mo><mn>1</mn></mrow></msubsup><mo>∙</mo><msup><mrow><mi>h</mi></mrow><mrow><mo>−</mo><mn>1</mn></mrow></msup></mrow></math></span>), likely due to its favorable hydrogen sorption properties and larger active phase surface area available for hydrogen (31 m²·g<sub>Co</sub>⁻¹). These findings highlight the potential of lanthanide oxides as supports and the importance of barium as a promoter in cobalt-based catalysts for ammonia synthesis.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115611"},"PeriodicalIF":5.3,"publicationDate":"2025-10-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322288","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 : 2025-10-10DOI: 10.1016/j.cattod.2025.115594
Alberto Pinto , Lidia Amodio , Martin Kubů , Jennifer Cueto , Pavla Eliášová , Patricia Pizarro , Jiří Čejka , David P. Serrano
Pyrolysis is a promising technique for converting waste plastics into oil, but the resulting liquid often contains halogens, particularly chlorine, which pose environmental and corrosion risks when used as fuel or refinery feedstock. These halogens primarily originate from materials such as PVC and other Cl-containing compounds present in the waste. This study evaluates the performance of several zeolites (TNU-9, MCM-22, MCM-49, MCM-56, and MCM-36) in the catalytic dehalogenation and upgrading of a real pyrolysis oil derived from waste plastics with a chlorine content of 290 ppm. Experiments were conducted using a fixed-bed catalytic reactor at 450 °C. All the tested catalysts improved the oil properties, decreasing its paraffin content and favouring the formation of aromatic, cyclic and olefinic hydrocarbons. This is positive regarding the possible use of this oil fraction in the formulation of transportation fuels or as a source of raw chemicals. The deepest modification was observed over MCM-36 zeolite, achieving the highest cracking activity into light olefins (mainly C3 and C4). Its superior performance is attributed to its high external surface area, mesopore volume, and accessible Brønsted acid sites, resulting from its pillarized structure. Moreover, MCM-36 was also the zeolite exhibiting the best oil dechlorination capability, which remained relatively stable along the time on stream in contrast to other zeolite catalysts. Analyses of the spent catalysts indicated that the deposited carbonaceous matter accumulates most of the Cl-containing species removed from the oil; hence, the overall oil upgrading process can be considered a combination of catalytic and adsorption effects. This material could be effectively regenerated by a sequential combination of Soxhlet extraction and calcination treatments.
{"title":"Dechlorination and upgrading of waste plastics pyrolysis oil over MWW and TUN zeolites","authors":"Alberto Pinto , Lidia Amodio , Martin Kubů , Jennifer Cueto , Pavla Eliášová , Patricia Pizarro , Jiří Čejka , David P. Serrano","doi":"10.1016/j.cattod.2025.115594","DOIUrl":"10.1016/j.cattod.2025.115594","url":null,"abstract":"<div><div>Pyrolysis is a promising technique for converting waste plastics into oil, but the resulting liquid often contains halogens, particularly chlorine, which pose environmental and corrosion risks when used as fuel or refinery feedstock. These halogens primarily originate from materials such as PVC and other Cl-containing compounds present in the waste. This study evaluates the performance of several zeolites (TNU-9, MCM-22, MCM-49, MCM-56, and MCM-36) in the catalytic dehalogenation and upgrading of a real pyrolysis oil derived from waste plastics with a chlorine content of 290 ppm. Experiments were conducted using a fixed-bed catalytic reactor at 450 °C. All the tested catalysts improved the oil properties, decreasing its paraffin content and favouring the formation of aromatic, cyclic and olefinic hydrocarbons. This is positive regarding the possible use of this oil fraction in the formulation of transportation fuels or as a source of raw chemicals. The deepest modification was observed over MCM-36 zeolite, achieving the highest cracking activity into light olefins (mainly C3 and C4). Its superior performance is attributed to its high external surface area, mesopore volume, and accessible Brønsted acid sites, resulting from its pillarized structure. Moreover, MCM-36 was also the zeolite exhibiting the best oil dechlorination capability, which remained relatively stable along the time on stream in contrast to other zeolite catalysts. Analyses of the spent catalysts indicated that the deposited carbonaceous matter accumulates most of the Cl-containing species removed from the oil; hence, the overall oil upgrading process can be considered a combination of catalytic and adsorption effects. This material could be effectively regenerated by a sequential combination of Soxhlet extraction and calcination treatments.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115594"},"PeriodicalIF":5.3,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145322094","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 : 2025-10-10DOI: 10.1016/j.cattod.2025.115606
Ahmad Mukhtar, Ekow Agyekum-Oduro, Sidra Saqib, Sarah Wu
Fischer-Tropsch synthesis (FTS) is a promising route for producing sustainable aviation fuel (SAF) by converting syngas derived from renewable sources into hydrocarbons within the jet fuel range (C9-C16). However, controlling product selectivity remains challenging due to the conventional Anderson-Schulz-Flory (ASF) distribution, which favors a broad hydrocarbon distribution. This review critically examines various experimentally demonstrated strategies to enhance and narrow the SAF selectivity in FTS. Key approaches include adjusting catalyst redox characteristics, modifying the reduction environment, optimizing metal-support interactions, shifting reaction equilibrium, and incorporating suitable promoters. Furthermore, syngas feed dilution with CO2 have been explored as additional means to suppress methane formation and maximize mid-distillate production. These strategies and machine learning collectively contribute to overcoming ASF limitations, enabling a more targeted synthesis of jet fuel-range hydrocarbons while improving overall process efficiency. By refining these approaches, FTS can be further optimized to support the transition toward cleaner and more sustainable aviation fuels.
{"title":"Strategies to enhance the (C9-C16) range sustainable aviation fuel selectivity in Fischer-Tropsch synthesis","authors":"Ahmad Mukhtar, Ekow Agyekum-Oduro, Sidra Saqib, Sarah Wu","doi":"10.1016/j.cattod.2025.115606","DOIUrl":"10.1016/j.cattod.2025.115606","url":null,"abstract":"<div><div>Fischer-Tropsch synthesis (FTS) is a promising route for producing sustainable aviation fuel (SAF) by converting syngas derived from renewable sources into hydrocarbons within the jet fuel range (C<sub>9</sub>-C<sub>16</sub>). However, controlling product selectivity remains challenging due to the conventional Anderson-Schulz-Flory (ASF) distribution, which favors a broad hydrocarbon distribution. This review critically examines various experimentally demonstrated strategies to enhance and narrow the SAF selectivity in FTS. Key approaches include adjusting catalyst redox characteristics, modifying the reduction environment, optimizing metal-support interactions, shifting reaction equilibrium, and incorporating suitable promoters. Furthermore, syngas feed dilution with CO<sub>2</sub> have been explored as additional means to suppress methane formation and maximize mid-distillate production. These strategies and machine learning collectively contribute to overcoming ASF limitations, enabling a more targeted synthesis of jet fuel-range hydrocarbons while improving overall process efficiency. By refining these approaches, FTS can be further optimized to support the transition toward cleaner and more sustainable aviation fuels.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115606"},"PeriodicalIF":5.3,"publicationDate":"2025-10-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264287","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}
Hollow silica spheres with radially oriented mesopores were used as microreactors for the two-phase reaction of the aldol condensation of butanal. The hollow spheres filled with 2 M sulfuric acid as a catalyst, which served as an aqueous phase, were added to the heptane solution of butanal, which served as an organic phase, and the mixture was heated at 95ºC. The reaction rate was higher than that of the emulsive two-phase reaction without the use of the hollow spheres because the droplets in the emulsion were larger than the hollow spheres. When microwave heating was used, the reaction rate increased compared with that when conventional heating was applied at the same temperature of the reaction mixture. Only the aqueous phase in the hollow spheres, where the reaction proceeded, was selectively heated by microwave irradiation because water effectively absorbs microwaves, whereas heptane cannot.
{"title":"Application of hollow silica spheres with radially oriented mesopores to microreactors for two-phase reactions heated by microwave irradiation","authors":"Masaki Okamoto , Hiroaki Ueda , Shuntaro Tsubaki , Yuji Wada","doi":"10.1016/j.cattod.2025.115595","DOIUrl":"10.1016/j.cattod.2025.115595","url":null,"abstract":"<div><div>Hollow silica spheres with radially oriented mesopores were used as microreactors for the two-phase reaction of the aldol condensation of butanal. The hollow spheres filled with 2 M sulfuric acid as a catalyst, which served as an aqueous phase, were added to the heptane solution of butanal, which served as an organic phase, and the mixture was heated at 95ºC. The reaction rate was higher than that of the emulsive two-phase reaction without the use of the hollow spheres because the droplets in the emulsion were larger than the hollow spheres. When microwave heating was used, the reaction rate increased compared with that when conventional heating was applied at the same temperature of the reaction mixture. Only the aqueous phase in the hollow spheres, where the reaction proceeded, was selectively heated by microwave irradiation because water effectively absorbs microwaves, whereas heptane cannot.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115595"},"PeriodicalIF":5.3,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264290","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}
Anionic hexaniobate clusters [Nb6O19]8 −, which act as a superbase catalyst, could be synthesized by the microwave-assisted hydrothermal method at 180℃ within 10 min with high purity, whereas the conventional hydrothermal synthesis method requires a long reaction time (>24 h). In this study, the mechanism of synthesizing [Nb6O19]8− by the microwave-assisted hydrothermal method was investigated by in situ quick-scan X-ray absorption fine structure and electrospray ionization time-of-flight mass spectroscopy. This revealed rapid [Nb6O19]8− nucleation along with dissolution of Nb2O5∙nH2O accompanied by the formation of mononuclear Nb species at 160℃. The unveiled mechanistic insights provide the controllability in products during microwave-assisted hydrothermal synthesis of polyoxoniobate clusters.
{"title":"Mechanism of synthesizing hexaniobate cluster by microwave-assisted hydrothermal reaction","authors":"Nattamon Panichakul , Hiroki Nagakari , Soichi Kikkawa , Shuntaro Tsubaki , Kotaro Higashi , Tomoya Uruga , Hideyuki Kawasoko , Seiji Yamazoe","doi":"10.1016/j.cattod.2025.115593","DOIUrl":"10.1016/j.cattod.2025.115593","url":null,"abstract":"<div><div>Anionic hexaniobate clusters [Nb<sub>6</sub>O<sub>19</sub>]<sup>8 −</sup>, which act as a superbase catalyst, could be synthesized by the microwave-assisted hydrothermal method at 180℃ within 10 min with high purity, whereas the conventional hydrothermal synthesis method requires a long reaction time (>24 h). In this study, the mechanism of synthesizing [Nb<sub>6</sub>O<sub>19</sub>]<sup>8−</sup> by the microwave-assisted hydrothermal method was investigated by <em>in situ</em> quick-scan X-ray absorption fine structure and electrospray ionization time-of-flight mass spectroscopy. This revealed rapid [Nb<sub>6</sub>O<sub>19</sub>]<sup>8−</sup> nucleation along with dissolution of Nb<sub>2</sub>O<sub>5</sub>∙<em>n</em>H<sub>2</sub>O accompanied by the formation of mononuclear Nb species at 160℃. The unveiled mechanistic insights provide the controllability in products during microwave-assisted hydrothermal synthesis of polyoxoniobate clusters.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115593"},"PeriodicalIF":5.3,"publicationDate":"2025-10-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264286","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 : 2025-10-06DOI: 10.1016/j.cattod.2025.115582
Katia Bernardo-Gusmão , José R. Gregório , Sibele B.C. Pergher
{"title":"Catalyzing reunions and chemical transformations: Selected works of the 22nd Brazilian Congress on Catalysis","authors":"Katia Bernardo-Gusmão , José R. Gregório , Sibele B.C. Pergher","doi":"10.1016/j.cattod.2025.115582","DOIUrl":"10.1016/j.cattod.2025.115582","url":null,"abstract":"","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115582"},"PeriodicalIF":5.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145462538","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}
In this study, several titanium suboxides containing Ti3 + (Ti2O3, Ti3O5, Ti4O7, and hydrogenated TiO2) were synthesized by reducing TiO2 using TiH2 or H2 as reducing agent, and these materials were used as support for CoOx catalysts. The structure, reduction properties, and catalytic performance of these catalysts for the hydrodeoxygenation (HDO) of anisole were compared, and the effect of the reducing properties of the titanium suboxide support on the oxidation state of CoOx species and catalytic performance was investigated. Redox reactions occurred between these titanium suboxides and the supported CoOx species, and as a result, CoOx was supported in a reduced state. As the proportion of Ti3+ in the titanium suboxides increased, the reduction of CoOx proceeded more progressively, and CoOx species were reduced to a near metallic state. The progressive reduction of CoOx increased the catalytic activity of the supported CoOx for the HDO reaction and also improved the catalytic lifetime. This study demonstrated that titanium suboxides with low mean titanium valence played an indirect role in improving the catalytic performance of the supported CoOx by promoting the reduction of CoOx.
{"title":"Reductive support effect of titanium suboxides on oxidation state and catalytic performance of TiOx-supported CoOx for hydrodeoxygenation of anisole","authors":"Weizhou Sun , Shuhei Shimoda , Yuichi Kamiya , Ryoichi Otomo","doi":"10.1016/j.cattod.2025.115591","DOIUrl":"10.1016/j.cattod.2025.115591","url":null,"abstract":"<div><div>In this study, several titanium suboxides containing Ti<sup>3 +</sup> (Ti<sub>2</sub>O<sub>3</sub>, Ti<sub>3</sub>O<sub>5</sub>, Ti<sub>4</sub>O<sub>7</sub>, and hydrogenated TiO<sub>2</sub>) were synthesized by reducing TiO<sub>2</sub> using TiH<sub>2</sub> or H<sub>2</sub> as reducing agent, and these materials were used as support for CoO<sub><em>x</em></sub> catalysts. The structure, reduction properties, and catalytic performance of these catalysts for the hydrodeoxygenation (HDO) of anisole were compared, and the effect of the reducing properties of the titanium suboxide support on the oxidation state of CoO<sub><em>x</em></sub> species and catalytic performance was investigated. Redox reactions occurred between these titanium suboxides and the supported CoO<sub><em>x</em></sub> species, and as a result, CoO<sub><em>x</em></sub> was supported in a reduced state. As the proportion of Ti<sup>3+</sup> in the titanium suboxides increased, the reduction of CoO<sub><em>x</em></sub> proceeded more progressively, and CoO<sub><em>x</em></sub> species were reduced to a near metallic state. The progressive reduction of CoO<sub><em>x</em></sub> increased the catalytic activity of the supported CoO<sub><em>x</em></sub> for the HDO reaction and also improved the catalytic lifetime. This study demonstrated that titanium suboxides with low mean titanium valence played an indirect role in improving the catalytic performance of the supported CoO<sub><em>x</em></sub> by promoting the reduction of CoO<sub><em>x</em></sub>.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115591"},"PeriodicalIF":5.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264289","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 : 2025-10-06DOI: 10.1016/j.cattod.2025.115596
Paula Sánchez-Morena , Jaime Jurado-Sánchez , Carlos Márquez-Álvarez , Virginia Martínez-Martínez , Joaquín Pérez-Pariente , Luis Gómez-Hortigüela
In this work we disclose for the first time the catalytic activity of Ge in germanosilicate zeolites for the aerobic oxidation of cyclohexene. Our results show that Ge in the -ITV framework displays a higher catalytic activity than Ge in the BEC framework, despite having a similar Ge content. This must be related to the different configuration of Ge in both frameworks, since Ge in -ITV locates preferably in interrupted ≡T-OH Q3 positions, similar to the more active ‘open’ sites of Ti(IV) and Sn(IV) in zeolites, while in the BEC framework Ge is in Q4 ‘closed’ configuration. Interestingly, pre-treatment of both calcined germanosilicate materials with 1-butanol results in a notable improvement of the catalytic activity, especially in terms of a reduction of the induction period. A detailed spectroscopic study reveals a special interaction of cyclohexene with ≡Ge-OH interrupted sites in the -ITV framework, displaying two types of interactions, through H-bonding and through a direct interaction with Ge. Moreover, cyclohexene is shown to form some type of complex with Ge sites in both BEC and -ITV frameworks, but they show a different nature as revealed by their distinct UV absorption bands, suggesting that Ge is able to pre-activate in some way cyclohexene for the oxidation reaction.
{"title":"Catalytic activity of germanosilicate zeolites in the aerobic oxidation of cyclohexene: Effect of Ge ‘open’ sites","authors":"Paula Sánchez-Morena , Jaime Jurado-Sánchez , Carlos Márquez-Álvarez , Virginia Martínez-Martínez , Joaquín Pérez-Pariente , Luis Gómez-Hortigüela","doi":"10.1016/j.cattod.2025.115596","DOIUrl":"10.1016/j.cattod.2025.115596","url":null,"abstract":"<div><div>In this work we disclose for the first time the catalytic activity of Ge in germanosilicate zeolites for the aerobic oxidation of cyclohexene. Our results show that Ge in the -ITV framework displays a higher catalytic activity than Ge in the BEC framework, despite having a similar Ge content. This must be related to the different configuration of Ge in both frameworks, since Ge in -ITV locates preferably in interrupted ≡T-OH Q3 positions, similar to the more active ‘open’ sites of Ti(IV) and Sn(IV) in zeolites, while in the BEC framework Ge is in Q4 ‘closed’ configuration. Interestingly, pre-treatment of both calcined germanosilicate materials with 1-butanol results in a notable improvement of the catalytic activity, especially in terms of a reduction of the induction period. A detailed spectroscopic study reveals a special interaction of cyclohexene with ≡Ge-OH interrupted sites in the -ITV framework, displaying two types of interactions, through H-bonding and through a direct interaction with Ge. Moreover, cyclohexene is shown to form some type of complex with Ge sites in both BEC and -ITV frameworks, but they show a different nature as revealed by their distinct UV absorption bands, suggesting that Ge is able to pre-activate in some way cyclohexene for the oxidation reaction.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115596"},"PeriodicalIF":5.3,"publicationDate":"2025-10-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264277","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 : 2025-10-02DOI: 10.1016/j.cattod.2025.115584
Yasin Khani , Fatemeh Khani-Aghesmaeili , Behzad Valizadeh , Bo Sung Kang , Kanghee Cho , Young-Kwon Park
Palm oil fatty acid distillate (PFAD), a byproduct of crude palm oil refining, has gained interest as a biodiesel feedstock. Concurrently, the growing accumulation of PET waste poses serious environmental challenges. In this study, sulfonated metal-organic frameworks (MOF) using linkers derived from PET waste were employed as catalysts for PFAD esterification using various alcohols. When methanol was employed as the solvent, high free fatty acid (FFA) conversions (∼100 %) were consistently observed within the temperature range of 60–120 °C. In contrast, FFA conversion increased significantly with ethanol and isopropanol at elevated temperatures, reaching 99.4 % and 99.7 % at 90 °C and 120 °C, respectively, due to enhanced molecular interactions. This enhancement is attributed to improved solvation effects and increased molecular mobility, which facilitate esterification at higher temperatures. Higher alcohol chain length negatively impacted esterification efficiency due to increased activation energy. A greater catalyst-to-feedstock (C/F) ratio also improved conversion. The sulfonic acid group (SO3H) content in MOFs played a crucial role: the MCS30 catalyst (30 % SO3H linker) yielded the highest FFA conversions with methanol, ethanol and isopropyl alcohol, followed by the 20 % and 10 % counterparts. This is attributed to the abundance of Brønsted acid sites facilitating proton donation during the reaction. MCS30 Catalyst also exhibited excellent reusability, with the FFA conversion dropping only slightly from 99.7 % to 95.2 % over four cycles. Overall, this approach offers a dual environmental benefit: mitigating PET plastic waste and enabling sustainable biodiesel production via PFAD esterification.
{"title":"Biodiesel production through the esterification of palm oil effluent using sulfonated MIL-101(Cr) catalyst using linkers derived from PET plastic waste","authors":"Yasin Khani , Fatemeh Khani-Aghesmaeili , Behzad Valizadeh , Bo Sung Kang , Kanghee Cho , Young-Kwon Park","doi":"10.1016/j.cattod.2025.115584","DOIUrl":"10.1016/j.cattod.2025.115584","url":null,"abstract":"<div><div>Palm oil fatty acid distillate (PFAD), a byproduct of crude palm oil refining, has gained interest as a biodiesel feedstock. Concurrently, the growing accumulation of PET waste poses serious environmental challenges. In this study, sulfonated metal-organic frameworks (MOF) using linkers derived from PET waste were employed as catalysts for PFAD esterification using various alcohols. When methanol was employed as the solvent, high free fatty acid (FFA) conversions (∼100 %) were consistently observed within the temperature range of 60–120 °C. In contrast, FFA conversion increased significantly with ethanol and isopropanol at elevated temperatures, reaching 99.4 % and 99.7 % at 90 °C and 120 °C, respectively, due to enhanced molecular interactions. This enhancement is attributed to improved solvation effects and increased molecular mobility, which facilitate esterification at higher temperatures. Higher alcohol chain length negatively impacted esterification efficiency due to increased activation energy. A greater catalyst-to-feedstock (C/F) ratio also improved conversion. The sulfonic acid group (SO<sub>3</sub>H) content in MOFs played a crucial role: the MCS30 catalyst (30 % SO<sub>3</sub>H linker) yielded the highest FFA conversions with methanol, ethanol and isopropyl alcohol, followed by the 20 % and 10 % counterparts. This is attributed to the abundance of Brønsted acid sites facilitating proton donation during the reaction. MCS30 Catalyst also exhibited excellent reusability, with the FFA conversion dropping only slightly from 99.7 % to 95.2 % over four cycles. Overall, this approach offers a dual environmental benefit: mitigating PET plastic waste and enabling sustainable biodiesel production via PFAD esterification.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"463 ","pages":"Article 115584"},"PeriodicalIF":5.3,"publicationDate":"2025-10-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145264288","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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