Pub Date : 2025-03-12DOI: 10.1016/j.cattod.2025.115274
Karolina A. Tarach , Anna Walczyk , Agata Olszewska , Julia Sobalska , Oliwia Rogala , Kinga Góra-Marek
This study investigates the conversion of ethanol to higher olefins using protonic chabazite (SSZ-13, SiAl = 8) zeolite, employing advanced FT-IR and UV–vis operando spectroscopic techniques, with concurrent mass spectrometry and gas chromatography examinations of the products. The utilisation of varying ethanol loads facilitates the examination of coke production and its progression relative to the feed quantity. The spectroscopic analysis clarifies the species formed on the catalyst's surface, while mass spectrometry and gas chromatography techniques verify the desorbed products. The counterparts in transforming ethanol and methanol to olefins via the recognised intermediates of the hydrocarbon pool mechanism are identified and examined in detail. Significant value-added information is obtained from in situ FT-IR studies complemented by mass spectrometry examination of the gas phase. The MCR-ALS analysis is utilised in spectroscopic operando investigations and offers significant insights into the findings. Furthermore, these investigations are substantiated by chromatographic examination of coke species obtained from spent catalysts.
{"title":"Operando FT-IR and UV–vis spectroscopic studies emphasise the nature of coke species formed over SSZ-13 zeolite during ethanol-to-hydrocarbons process","authors":"Karolina A. Tarach , Anna Walczyk , Agata Olszewska , Julia Sobalska , Oliwia Rogala , Kinga Góra-Marek","doi":"10.1016/j.cattod.2025.115274","DOIUrl":"10.1016/j.cattod.2025.115274","url":null,"abstract":"<div><div>This study investigates the conversion of ethanol to higher olefins using protonic chabazite (SSZ-13, SiAl = 8) zeolite, employing advanced FT-IR and UV–vis operando spectroscopic techniques, with concurrent mass spectrometry and gas chromatography examinations of the products. The utilisation of varying ethanol loads facilitates the examination of coke production and its progression relative to the feed quantity. The spectroscopic analysis clarifies the species formed on the catalyst's surface, while mass spectrometry and gas chromatography techniques verify the desorbed products. The counterparts in transforming ethanol and methanol to olefins via the recognised intermediates of the hydrocarbon pool mechanism are identified and examined in detail. Significant value-added information is obtained from in situ FT-IR studies complemented by mass spectrometry examination of the gas phase. The MCR-ALS analysis is utilised in spectroscopic operando investigations and offers significant insights into the findings. Furthermore, these investigations are substantiated by chromatographic examination of coke species obtained from spent catalysts.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115274"},"PeriodicalIF":5.2,"publicationDate":"2025-03-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143637597","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 : 2025-03-10DOI: 10.1016/j.cattod.2025.115271
Xi Shen , Zhenyu Zhao , Hong Li , Xin Gao
The recycling and upcycling of waste plastics into high-value products by pyrolysis is a critical challenge caused by its time/energy-consuming problems, which can be overcome by employing microwave-assisted catalytic pyrolysis due to its rapid pyrolysis rates and high product yields. This study presents a facile method for the synthesis of catalysts for microwave-assisted pyrolysis of waste plastics, utilizing the pyrolytic products as raw materials. In this case, a microwave thermal shock strategy is developed to efficiently anchor iron nanoparticles on carbon nanotubes (CNTs). This method recycles a portion of pyrolysis products back into the catalyst pool for plastic transformation into new CNTs, reducing the consumption for preparing additional catalysts. The precursors exposed to 50 W microwave irradiation reaches above 2000 °C within seconds, allowing Fe nanoparticles to be uniformly impregnated within the carbon nanotube matrix. The formed iron-doped CNTs shows high activity for microwave-assisted pyrolysis, generating CNTs with D/G ratios at 0.31. The recycling and reconstruction of CNTs after multiple pyrolysis form a cross-lined network structure, which facilitates electron transition and can be utilized for fabricating electrocatalysts. Nitrogen doping further improves the onset potential to 0.923 V vs. RHE, making them viable candidates for electrocatalytic applications in oxygen reduction reactions. In summary, our findings demonstrate the feasibility of this approach to reactive pyrolysis products that serve as catalysis for microwave-assisted pyrolysis, with the potential to reduce volatile organic compound emissions and capital expenditure in catalyst preparation, offering a greener and more efficient pathway for plastic waste management and catalyst production.
{"title":"Iron-doped carbon nanotubes via microwave shock: Recyclability in polypropylene pyrolysis for ORR catalyst manufacturing","authors":"Xi Shen , Zhenyu Zhao , Hong Li , Xin Gao","doi":"10.1016/j.cattod.2025.115271","DOIUrl":"10.1016/j.cattod.2025.115271","url":null,"abstract":"<div><div>The recycling and upcycling of waste plastics into high-value products by pyrolysis is a critical challenge caused by its time/energy-consuming problems, which can be overcome by employing microwave-assisted catalytic pyrolysis due to its rapid pyrolysis rates and high product yields. This study presents a facile method for the synthesis of catalysts for microwave-assisted pyrolysis of waste plastics, utilizing the pyrolytic products as raw materials. In this case, a microwave thermal shock strategy is developed to efficiently anchor iron nanoparticles on carbon nanotubes (CNTs). This method recycles a portion of pyrolysis products back into the catalyst pool for plastic transformation into new CNTs, reducing the consumption for preparing additional catalysts. The precursors exposed to 50 W microwave irradiation reaches above 2000 °C within seconds, allowing Fe nanoparticles to be uniformly impregnated within the carbon nanotube matrix. The formed iron-doped CNTs shows high activity for microwave-assisted pyrolysis, generating CNTs with D/G ratios at 0.31. The recycling and reconstruction of CNTs after multiple pyrolysis form a cross-lined network structure, which facilitates electron transition and can be utilized for fabricating electrocatalysts. Nitrogen doping further improves the onset potential to 0.923 V vs. RHE, making them viable candidates for electrocatalytic applications in oxygen reduction reactions. In summary, our findings demonstrate the feasibility of this approach to reactive pyrolysis products that serve as catalysis for microwave-assisted pyrolysis, with the potential to reduce volatile organic compound emissions and capital expenditure in catalyst preparation, offering a greener and more efficient pathway for plastic waste management and catalyst production.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115271"},"PeriodicalIF":5.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621062","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 : 2025-03-10DOI: 10.1016/j.cattod.2025.115262
V.D. Mercader, P. Aragüés-Aldea, P. Durán, E. Francés, J. Herguido, J.A. Peña
This study investigates the integration of catalytic CO2 methanation and water adsorption using a Ni-Fe-based catalyst and LTA 5 A zeolite to enhance methane production via the Sabatier reaction. By mitigating thermodynamic limitations through in situ water removal, the research explores key operational parameters, including temperature, space velocity, and H₂:CO₂ feed ratios, to optimize process performance. The findings highlight that a temperature of 300 °C, a WHSV of 1.50 × 104 (STP) mL·gcat−1·h−1 (4.86 gCO2·gcat⁻¹·h⁻¹), and a H₂:CO₂ molar ratio equal to 5:1, result in enhanced methane yields, shifting thermodynamic equilibrium due to water sorption during initial stages. The presence of methane in the feed, representative of a biogas, demonstrated negligible effects on methane yields under optimal conditions, underscoring the method’s feasibility for direct biogas upgrading. While the process achieved significant intensification, challenges such as loss of activity of the bed of solids (catalyst plus water adsorbent) were identified, necessitating further advancements in both catalyst and adsorbent stability, as well as a deeper study on their interaction. The study provides a pathway for scaling up adsorption-enhanced methanation technologies to achieve renewable methane production, addressing the dual goals of carbon management and energy storage.
{"title":"Optimizing Sorption Enhanced Methanation (SEM) of CO2 with Ni3Fe + LTA 5 A mixtures","authors":"V.D. Mercader, P. Aragüés-Aldea, P. Durán, E. Francés, J. Herguido, J.A. Peña","doi":"10.1016/j.cattod.2025.115262","DOIUrl":"10.1016/j.cattod.2025.115262","url":null,"abstract":"<div><div>This study investigates the integration of catalytic CO<sub>2</sub> methanation and water adsorption using a Ni-Fe-based catalyst and LTA 5 A zeolite to enhance methane production via the Sabatier reaction. By mitigating thermodynamic limitations through <em>in situ</em> water removal, the research explores key operational parameters, including temperature, space velocity, and H₂:CO₂ feed ratios, to optimize process performance. The findings highlight that a temperature of 300 °C, a <em>WHSV</em> of 1.50 × 10<sup>4</sup> (STP) mL·g<sub>cat</sub><sup>−1</sup>·h<sup>−1</sup> (4.86 g<sub>CO2</sub>·g<sub>cat</sub>⁻¹·h⁻¹), and a H₂:CO₂ molar ratio equal to 5:1, result in enhanced methane yields, shifting thermodynamic equilibrium due to water sorption during initial stages. The presence of methane in the feed, representative of a biogas, demonstrated negligible effects on methane yields under optimal conditions, underscoring the method’s feasibility for direct biogas upgrading. While the process achieved significant intensification, challenges such as loss of activity of the bed of solids (catalyst plus water adsorbent) were identified, necessitating further advancements in both catalyst and adsorbent stability, as well as a deeper study on their interaction. The study provides a pathway for scaling up adsorption-enhanced methanation technologies to achieve renewable methane production, addressing the dual goals of carbon management and energy storage.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115262"},"PeriodicalIF":5.2,"publicationDate":"2025-03-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143643046","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 : 2025-03-06DOI: 10.1016/j.cattod.2025.115260
Lidia López-Gómez , Marina Ronda-Leal , Salvador Pérez-Huertas , Antonio A. Romero , Rafael Luque
A series of bimetallic oxides (Al2O3-ZrO2@C) has been synthesized using a metal-organic-framework (NH2-UiO-66) as a sacrificial agent by both impregnation and mechanochemical methods. The synthesized materials were used in heterogeneous catalysis for the direct conversion of a promising biomass-based building block, i.e., methyl levulinate to γ-valerolactone (GVL). A complete set of characterization, including N2 adsorption/desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) was carried out. The incorporation of aluminum into the catalyst system led to a significant increase in the GVL yield. The conversion rate achieved with the mechanochemistry-based samples doubled that obtained by the impregnation samples. The material prepared via mechanochemistry with the larger Al2O3/ZrO2 ratio exhibited the greatest catalytic activity, i.e., 79 % conversion and 87 % selectivity. GVL is considered a promising biomass-derived platform chemical for numerous applications, including bio-materials, fuels or fuel additives, and various chemical intermediates.
{"title":"Mechanochemical vs impregnation synthesis of metal oxides from pyrolyzed MOFs in microwave-assisted methyl levulinate conversion to gamma-valerolactone","authors":"Lidia López-Gómez , Marina Ronda-Leal , Salvador Pérez-Huertas , Antonio A. Romero , Rafael Luque","doi":"10.1016/j.cattod.2025.115260","DOIUrl":"10.1016/j.cattod.2025.115260","url":null,"abstract":"<div><div>A series of bimetallic oxides (Al<sub>2</sub>O<sub>3</sub>-ZrO<sub>2</sub>@C) has been synthesized using a metal-organic-framework (NH<sub>2</sub>-UiO-66) as a sacrificial agent by both impregnation and mechanochemical methods. The synthesized materials were used in heterogeneous catalysis for the direct conversion of a promising biomass-based building block, i.e., methyl levulinate to γ-valerolactone (GVL). A complete set of characterization, including N<sub>2</sub> adsorption/desorption, X-ray diffraction (XRD), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and Fourier transform infrared spectroscopy (FTIR) was carried out. The incorporation of aluminum into the catalyst system led to a significant increase in the GVL yield. The conversion rate achieved with the mechanochemistry-based samples doubled that obtained by the impregnation samples. The material prepared via mechanochemistry with the larger Al<sub>2</sub>O<sub>3</sub>/ZrO<sub>2</sub> ratio exhibited the greatest catalytic activity, i.e., 79 % conversion and 87 % selectivity. GVL is considered a promising biomass-derived platform chemical for numerous applications, including bio-materials, fuels or fuel additives, and various chemical intermediates.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115260"},"PeriodicalIF":5.2,"publicationDate":"2025-03-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143593644","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 : 2025-03-05DOI: 10.1016/j.cattod.2025.115257
Ho-Ryong Park , Beom-Jun Kim , Su-Jin Ryu , Yukwon Jeon , Sang Soo Lee , Jong-Wook Bae , Hyun-Seog Roh
We developed a customized catalyst for the super-dry reforming of methane (S-DRM) reaction, designed to maximize CO2 utilization compared to the conventional dry reforming of methane (DRM) reaction. The introduction of CeO2 induced strong metal-support interactions (SMSI) in the Ni/MgO/SBA-15 catalyst, facilitating the high dispersion of Ni particles. Consequently, the crystallite size of metallic Ni (Ni0) was reduced, resulting in an increased number of Ni active sites. Furthermore, the incorporation of CeO2 promoted the formation of oxygen vacancies (OVs), thereby enhancing CO2 activation and improving the efficiency of the S-DRM reaction. As the CeO2 content increased, the proportion of SBA-15 decreased, leading to a gradual reduction in surface area. However, at excessive CeO2 content, a drastic decline in surface area was observed, which also resulted in a decrease in OVs that had previously shown an increasing trend with rising CeO2 content. These changes could potentially diminish catalyst performance despite the enhanced SMSI. Therefore, maintaining an appropriate ratio of CeO2:SBA-15 is crucial for maximizing catalyst performance and ensuring prolonged stability. The optimal catalyst, NMCS250, effectively balanced these factors, exhibiting high Ni dispersion, increased OVs, and basicity, which contributed to excellent catalytic activity and stability. Overall, NMCS250 was identified as the optimal catalyst, demonstrating superior catalytic performance due to its elevated Ni dispersion, increased oxygen vacancies, and basicity.
{"title":"Super-dry reforming of methane over surface oxygen mobility enhanced Ni/MgO-Ce/SBA-15 catalysts","authors":"Ho-Ryong Park , Beom-Jun Kim , Su-Jin Ryu , Yukwon Jeon , Sang Soo Lee , Jong-Wook Bae , Hyun-Seog Roh","doi":"10.1016/j.cattod.2025.115257","DOIUrl":"10.1016/j.cattod.2025.115257","url":null,"abstract":"<div><div>We developed a customized catalyst for the super-dry reforming of methane (S-DRM) reaction, designed to maximize CO<sub>2</sub> utilization compared to the conventional dry reforming of methane (DRM) reaction. The introduction of CeO<sub>2</sub> induced strong metal-support interactions (SMSI) in the Ni/MgO/SBA-15 catalyst, facilitating the high dispersion of Ni particles. Consequently, the crystallite size of metallic Ni (Ni<sup>0</sup>) was reduced, resulting in an increased number of Ni active sites. Furthermore, the incorporation of CeO<sub>2</sub> promoted the formation of oxygen vacancies (OVs), thereby enhancing CO<sub>2</sub> activation and improving the efficiency of the S-DRM reaction. As the CeO<sub>2</sub> content increased, the proportion of SBA-15 decreased, leading to a gradual reduction in surface area. However, at excessive CeO<sub>2</sub> content, a drastic decline in surface area was observed, which also resulted in a decrease in OVs that had previously shown an increasing trend with rising CeO<sub>2</sub> content. These changes could potentially diminish catalyst performance despite the enhanced SMSI. Therefore, maintaining an appropriate ratio of CeO<sub>2</sub>:SBA-15 is crucial for maximizing catalyst performance and ensuring prolonged stability. The optimal catalyst, NMCS250, effectively balanced these factors, exhibiting high Ni dispersion, increased OVs, and basicity, which contributed to excellent catalytic activity and stability. Overall, NMCS250 was identified as the optimal catalyst, demonstrating superior catalytic performance due to its elevated Ni dispersion, increased oxygen vacancies, and basicity.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115257"},"PeriodicalIF":5.2,"publicationDate":"2025-03-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143577791","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 : 2025-03-04DOI: 10.1016/j.cattod.2025.115261
Alua M. Manabayeva , Päivi Mäki-Arvela , Zuzana Vajglová , Mark Martinéz-Klimov , Olha Yevdokimova , Anssi Peuronen , Mika Lastusaari , Teija Tirri , Svetlana A. Tungatarova , Tolkyn S. Baizhumanova , Kaisar Kassymkan , Gulnar N. Kaumenova , Manapkhan Zhumabek , Daulet A. Zhumadullaev , Dinmukhamed Shoganbek , Dmitry Yu. Murzin
In the current work, nickel and magnesia containing catalysts synthesized by solution combustion synthesis (SCS) and impregnation were used for dry reforming of methane (DRM). The present research showcased the difference of two preparation methods and demonstrated the influence of temperature cycling and various duration on the activity of Ni-Mg catalysts (30 min, 10 h, 20 h, 200 h TOS). It was reported that Ni-Mg-Al catalysts exhibited mainly crystalline MgAl2O4 and nickel oxide in both fresh and spent catalysts confirmed by XRD results. As seen from TEM images, nickel particles ranged from 12 to 36 nm. Small metal particles indicate the strong interactions between the metal and the support. Moreover, these particles were localized at the tip of carbon nanotube indicating their activity. According to TPD, for all catalysts large amounts of basic sites and strong interactions between the metal and CO2 were observed. Ni-Mg-Al obtained with SCS possesses 0.19 wt%·g−1Ni of carbon content, which was much lower than that of Ni-Mg catalyst. It was found that SCS derived Ni-Mg-Al catalyst exhibited higher activity compared to its reduced analogue prepared by impregnation. The former catalyst showed stable performance during 200 h test with a decreasing coking rate. The metal particle size was lower for this spent catalyst in comparison with Ni-Mg-Al tested for 20 h test.
{"title":"Mg-modified Ni-based catalysts prepared by the solution combustion synthesis for dry reforming of methane","authors":"Alua M. Manabayeva , Päivi Mäki-Arvela , Zuzana Vajglová , Mark Martinéz-Klimov , Olha Yevdokimova , Anssi Peuronen , Mika Lastusaari , Teija Tirri , Svetlana A. Tungatarova , Tolkyn S. Baizhumanova , Kaisar Kassymkan , Gulnar N. Kaumenova , Manapkhan Zhumabek , Daulet A. Zhumadullaev , Dinmukhamed Shoganbek , Dmitry Yu. Murzin","doi":"10.1016/j.cattod.2025.115261","DOIUrl":"10.1016/j.cattod.2025.115261","url":null,"abstract":"<div><div>In the current work, nickel and magnesia containing catalysts synthesized by solution combustion synthesis (SCS) and impregnation were used for dry reforming of methane (DRM). The present research showcased the difference of two preparation methods and demonstrated the influence of temperature cycling and various duration on the activity of Ni-Mg catalysts (30 min, 10 h, 20 h, 200 h TOS). It was reported that Ni-Mg-Al catalysts exhibited mainly crystalline MgAl<sub>2</sub>O<sub>4</sub> and nickel oxide in both fresh and spent catalysts confirmed by XRD results. As seen from TEM images, nickel particles ranged from 12 to 36 nm. Small metal particles indicate the strong interactions between the metal and the support. Moreover, these particles were localized at the tip of carbon nanotube indicating their activity. According to TPD, for all catalysts large amounts of basic sites and strong interactions between the metal and CO<sub>2</sub> were observed. Ni-Mg-Al obtained with SCS possesses 0.19 wt%·g<sup>−1</sup><sub>Ni</sub> of carbon content, which was much lower than that of Ni-Mg catalyst. It was found that SCS derived Ni-Mg-Al catalyst exhibited higher activity compared to its reduced analogue prepared by impregnation. The former catalyst showed stable performance during 200 h test with a decreasing coking rate. The metal particle size was lower for this spent catalyst in comparison with Ni-Mg-Al tested for 20 h test.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115261"},"PeriodicalIF":5.2,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143562504","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 : 2025-03-01DOI: 10.1016/j.cattod.2025.115258
Benjamin Niethammer , Foteini Zormpa , Gia Trung Hoang , Nikolaj Aljoscha Slaby , Thomas Anthony Zevaco , Stamatia Karakoulia , Ulrich Arnold , Jörg Sauer
The influence of Pd loading on the conversion of dimethyl ether (DME) to hydrocarbons (DTH) was investigated for *MRE-type zeolite catalysts. Catalysts with different Pd loadings were prepared by incipient wetness impregnation and characterized in terms of morphology, composition and acidity. Co-feeding of H2 during DME conversion increased the resistance of the Pd/*MRE catalysts to deactivation, which significantly increased their lifetimes and thus conversion capacities. The product spectra show high olefin contents, comprising light olefins and higher olefins in the C5–C11 range, while contents of aromatics are low. H2 co-feeding reduces the formation of cyclic hydrocarbons and increases the formation of n- and iso-alkanes as well as olefins. Higher Pd loadings slightly decrease olefin production but increase paraffin formation, indicating direct hydrogenation of olefins on Pd nanoparticles. The olefin-rich products offer several possibilities for further processing to fuels and chemicals.
{"title":"Conversion of dimethyl ether to hydrocarbons catalyzed by Pd-loaded *MRE zeolites","authors":"Benjamin Niethammer , Foteini Zormpa , Gia Trung Hoang , Nikolaj Aljoscha Slaby , Thomas Anthony Zevaco , Stamatia Karakoulia , Ulrich Arnold , Jörg Sauer","doi":"10.1016/j.cattod.2025.115258","DOIUrl":"10.1016/j.cattod.2025.115258","url":null,"abstract":"<div><div>The influence of Pd loading on the conversion of dimethyl ether (DME) to hydrocarbons (DTH) was investigated for *MRE-type zeolite catalysts. Catalysts with different Pd loadings were prepared by incipient wetness impregnation and characterized in terms of morphology, composition and acidity. Co-feeding of H<sub>2</sub> during DME conversion increased the resistance of the Pd/*MRE catalysts to deactivation, which significantly increased their lifetimes and thus conversion capacities. The product spectra show high olefin contents, comprising light olefins and higher olefins in the C<sub>5</sub>–C<sub>11</sub> range, while contents of aromatics are low. H<sub>2</sub> co-feeding reduces the formation of cyclic hydrocarbons and increases the formation of n- and iso-alkanes as well as olefins. Higher Pd loadings slightly decrease olefin production but increase paraffin formation, indicating direct hydrogenation of olefins on Pd nanoparticles. The olefin-rich products offer several possibilities for further processing to fuels and chemicals.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115258"},"PeriodicalIF":5.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143621448","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 : 2025-03-01DOI: 10.1016/j.cattod.2025.115256
Elena Gómez-Bravo, Unai De-La-Torre, José A. González-Marcos, Juan R. González-Velasco, Beñat Pereda-Ayo
The CO2 methanation reaction is a promising solution for renewable energy storage. However, the process is challenged by thermal management due to its exothermic nature, leading to hot spots that complicate reactor operation and scale-up. This study combines experimental and simulation approaches to optimize the operation of a bench-scale fixed-bed reactor. Experimental results show that reactor wall temperature, flow rate, and nitrogen dilution significantly affect temperature profiles and CO2 conversion. As a refrigeration strategy, it has been studied the use of pressurized air jackets to improve heat dissipation and stabilize the operation. A dynamic 1D heterogeneous model validated these findings and enabled simulation-based optimization. Non-uniform particle size distributions, metal loading, and SiC dilution strategies effectively mitigated hot spots without compromising CH4 yield. These results offer critical insights into reactor design, ensuring stable operation and high efficiency.
{"title":"Optimizing operational strategies in a non-isothermal bench-scale fixed-bed reactor for CO2 hydrogenation to CH4 combining experimental and modeling and simulation approaches","authors":"Elena Gómez-Bravo, Unai De-La-Torre, José A. González-Marcos, Juan R. González-Velasco, Beñat Pereda-Ayo","doi":"10.1016/j.cattod.2025.115256","DOIUrl":"10.1016/j.cattod.2025.115256","url":null,"abstract":"<div><div>The CO<sub>2</sub> methanation reaction is a promising solution for renewable energy storage. However, the process is challenged by thermal management due to its exothermic nature, leading to hot spots that complicate reactor operation and scale-up. This study combines experimental and simulation approaches to optimize the operation of a bench-scale fixed-bed reactor. Experimental results show that reactor wall temperature, flow rate, and nitrogen dilution significantly affect temperature profiles and CO<sub>2</sub> conversion. As a refrigeration strategy, it has been studied the use of pressurized air jackets to improve heat dissipation and stabilize the operation. A dynamic 1D heterogeneous model validated these findings and enabled simulation-based optimization. Non-uniform particle size distributions, metal loading, and SiC dilution strategies effectively mitigated hot spots without compromising CH<sub>4</sub> yield. These results offer critical insights into reactor design, ensuring stable operation and high efficiency.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115256"},"PeriodicalIF":5.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549288","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 : 2025-03-01DOI: 10.1016/j.cattod.2025.115259
Dwi Hantoko , Wasim Ullah Khan , Ali M. Alomran , Ariel H. Gursida , Mohammed Saud Hammad , Srinivasakannan Chandrasekar , Mohammad M. Hossain
Catalytic methane decomposition is a promising process for co-production of COx free hydrogen and carbon nanomaterials. In this work, iron-based catalysts, supported on ZSM5, were studied as an active catalyst for methane decomposition and nickel and cobalt were used to boost the methane conversion and catalyst stability. The prepared catalysts were tested at 700 °C with the 9:1 CH4 to Ar feed ratio under atmospheric pressure in a fixed bed tubular reactor. The diffraction peaks showed the formation of corresponding metal oxides and their combination species. The activity profiles implied that promoted iron-based catalyst (NiFe/ZSM5) outperformed the rest of the catalysts with an initial activity of 81.51 % that remained 75 % at the end of 170 min time-on-stream. The unpromoted (Fe/ZSM5) suffered deactivation over time and hence NiFe/ZSM5 turned out to be the active and stable catalyst among the tested catalysts. The high-resolution transition electron microscopy (HRTEM) images of the best catalyst indicated the growth of multiwalled carbon nanotubes which followed tip-base-growth mechanisms.
{"title":"The role of promoters in enhancing hydrogen production during catalytic decomposition of methane","authors":"Dwi Hantoko , Wasim Ullah Khan , Ali M. Alomran , Ariel H. Gursida , Mohammed Saud Hammad , Srinivasakannan Chandrasekar , Mohammad M. Hossain","doi":"10.1016/j.cattod.2025.115259","DOIUrl":"10.1016/j.cattod.2025.115259","url":null,"abstract":"<div><div>Catalytic methane decomposition is a promising process for co-production of CO<sub>x</sub> free hydrogen and carbon nanomaterials. In this work, iron-based catalysts, supported on ZSM5, were studied as an active catalyst for methane decomposition and nickel and cobalt were used to boost the methane conversion and catalyst stability. The prepared catalysts were tested at 700 °C with the 9:1 CH<sub>4</sub> to Ar feed ratio under atmospheric pressure in a fixed bed tubular reactor. The diffraction peaks showed the formation of corresponding metal oxides and their combination species. The activity profiles implied that promoted iron-based catalyst (NiFe/ZSM5) outperformed the rest of the catalysts with an initial activity of 81.51 % that remained 75 % at the end of 170 min time-on-stream. The unpromoted (Fe/ZSM5) suffered deactivation over time and hence NiFe/ZSM5 turned out to be the active and stable catalyst among the tested catalysts. The high-resolution transition electron microscopy (HRTEM) images of the best catalyst indicated the growth of multiwalled carbon nanotubes which followed tip-base-growth mechanisms.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115259"},"PeriodicalIF":5.2,"publicationDate":"2025-03-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143549289","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 : 2025-02-28DOI: 10.1016/j.cattod.2025.115254
Kiheon Hong , Welman C. Elias , Kimberly N. Heck , Tanguy Terlier , Dimpel Dimpel , Wei Qian , Bing Liu , Takao Kurihara , Michael S. Wong
Nitrate/nitrite pollution of water resources is an ubiquitous problem primarily due to the over application of fertilizer. While commercial methods which remove nitrates/nitrites exist, techniques which directly destroy the pollutants are more desirable. Nitrate/nitrite reduction by precious metal catalysts is one promising method to permanently convert nitrate/nitrite to non-toxic analogs. Amongst these, iron-platinum (“FePt”) compositions are generally considered inactive for NO2-. In this study, we demonstrate that bimetallic FePt catalysts synthesized via a pulsed-laser-ablation-in-liquid method (“PLAL-FePt NPs”) exhibit notably improved activity for NO2- compared to those synthesized by incipient wetness impregnation (“FePt/SiO2”) with the same elemental composition. While FePt/SiO2 catalyst (60 at% Pt) had nitrite reduction activity, the PLAL-FePt NPs (57 at%) were ∼8 times more active (kcat ≈ 4.6 vs. 39.5 Lmin−1gsurface Pt−1) on a per surface Pt basis. When compared to the monometallic Pt catalyst, the PLAL-FePt NPs were ∼2 times more active. X-ray diffraction (XRD) show PLAL-FePt NPs to have intermetallic phases of Pt3Fe1 and Pt1Fe1. In contrast, FePt/SiO2 have multiple phases (Pt, Pt3Fe1, Pt1Fe1, and Pt1Fe3). X-ray photoelectron spectroscopy (XPS) showed that Pt gained electron density from Fe, correlating to the increased nitrite reduction activity of both bimetallic materials. These findings indicate an earth-abundant element like iron can improve platinum catalysis, highlighting Fe-Pt intermetallic alloys for further study as hydrogenation catalysts.
{"title":"Pulsed laser ablation-synthesized FePt nanoparticles have enhanced catalytic nitrite reduction activity","authors":"Kiheon Hong , Welman C. Elias , Kimberly N. Heck , Tanguy Terlier , Dimpel Dimpel , Wei Qian , Bing Liu , Takao Kurihara , Michael S. Wong","doi":"10.1016/j.cattod.2025.115254","DOIUrl":"10.1016/j.cattod.2025.115254","url":null,"abstract":"<div><div>Nitrate/nitrite pollution of water resources is an ubiquitous problem primarily due to the over application of fertilizer. While commercial methods which remove nitrates/nitrites exist, techniques which directly destroy the pollutants are more desirable. Nitrate/nitrite reduction by precious metal catalysts is one promising method to permanently convert nitrate/nitrite to non-toxic analogs. Amongst these, iron-platinum (“FePt”) compositions are generally considered inactive for NO<sub>2</sub><sup>-</sup>. In this study, we demonstrate that bimetallic FePt catalysts synthesized via a pulsed-laser-ablation-in-liquid method (“PLAL-FePt NPs”) exhibit notably improved activity for NO<sub>2</sub><sup>-</sup> compared to those synthesized by incipient wetness impregnation (“FePt/SiO<sub>2</sub>”) with the same elemental composition. While FePt/SiO<sub>2</sub> catalyst (60 at% Pt) had nitrite reduction activity, the PLAL-FePt NPs (57 at%) were ∼8 times more active (k<sub>cat</sub> ≈ 4.6 <em>vs.</em> 39.5 Lmin<sup>−1</sup>g<sub>surface Pt</sub><sup>−1</sup>) on a per surface Pt basis. When compared to the monometallic Pt catalyst, the PLAL-FePt NPs were ∼2 times more active. X-ray diffraction (XRD) show PLAL-FePt NPs to have intermetallic phases of Pt<sub>3</sub>Fe<sub>1</sub> and Pt<sub>1</sub>Fe<sub>1</sub>. In contrast, FePt/SiO<sub>2</sub> have multiple phases (Pt, Pt<sub>3</sub>Fe<sub>1</sub>, Pt<sub>1</sub>Fe<sub>1</sub>, and Pt<sub>1</sub>Fe<sub>3</sub>). X-ray photoelectron spectroscopy (XPS) showed that Pt gained electron density from Fe, correlating to the increased nitrite reduction activity of both bimetallic materials. These findings indicate an earth-abundant element like iron can improve platinum catalysis, highlighting Fe-Pt intermetallic alloys for further study as hydrogenation catalysts.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"453 ","pages":"Article 115254"},"PeriodicalIF":5.2,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143548761","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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