Conventionally, the molecular weight of polyolefin-based resins is regulated by H2 during polymerization. In pursuit of finding an alternative for the substitution of H2, coordinative chain transfer copolymerization (CCTcoP), comprising of (EBI)ZrCl2, MMAO-12, TIBA, and Zn(Et)2 (DEZ), was undertaken. Chemical composition determination by 13C NMR analysis revealed that zinc-assisted copolymerization (ZAC) altered comonomer sequence distribution and its content in the resulting copolymers. DEZ induced different propagating sites exhibiting an exclusive tendency for ethylene insertion (: 11.58–18.17). This preference steered the active centers toward the production of crystallizable segmented copolymers, primarily long ethylene-rich segments possessing more isolated propylene units, a higher EEE triad (45.1–55.9 %), a larger average ethylene sequence E (4.1–5.8), a reduced random index (0.37–0.50), and an appreciably higher melting temperature (DSC). Conversely, zinc-unassisted copolymerization (ZUC) afforded random copolymers with noticeably higher random index (0.65–0.82), lower melting points, : 3.53–5.87, EEE triads (12.9–17.9 %), and E (1.75–2.54).
{"title":"Deciphering the function of Zn(Et)2 in tailoring comonomer insertion sequence during coordinative chain transfer ethylene/propylene copolymerization","authors":"Mojtaba Omidvar , Saeid Ahmadjo , Mohammad Mahdi Mortazavi, Maryamsadat Beheshti","doi":"10.1016/j.apcata.2024.120069","DOIUrl":"10.1016/j.apcata.2024.120069","url":null,"abstract":"<div><div>Conventionally, the molecular weight of polyolefin-based resins is regulated by H<sub>2</sub> during polymerization. In pursuit of finding an alternative for the substitution of H<sub>2,</sub> coordinative chain transfer copolymerization (CCTcoP), comprising of (EBI)ZrCl<sub>2</sub>, MMAO-12, TIBA, and Zn(Et)<sub>2</sub> (DEZ), was undertaken. Chemical composition determination by <sup>13</sup>C NMR analysis revealed that zinc-assisted copolymerization (ZAC) altered comonomer sequence distribution and its content in the resulting copolymers. DEZ induced different propagating sites exhibiting an exclusive tendency for ethylene insertion (<span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>E</mi></mrow></msub></math></span>: 11.58–18.17). This preference steered the active centers toward the production of crystallizable segmented copolymers, primarily long ethylene-rich segments possessing more isolated propylene units, a higher EEE triad (45.1–55.9 %), a larger average ethylene sequence <span><math><mover><mrow><mi>n</mi></mrow><mo>¯</mo></mover></math></span><sub>E</sub> (4.1–5.8), a reduced random index (0.37–0.50), and an appreciably higher melting temperature (DSC). Conversely, zinc-unassisted copolymerization (ZUC) afforded random copolymers with noticeably higher random index (0.65–0.82), lower melting points, <span><math><msub><mrow><mi>r</mi></mrow><mrow><mi>E</mi></mrow></msub></math></span>: 3.53–5.87, EEE triads (12.9–17.9 %), and <span><math><mover><mrow><mi>n</mi></mrow><mo>¯</mo></mover></math></span><sub>E</sub> (1.75–2.54).</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"691 ","pages":"Article 120069"},"PeriodicalIF":4.7,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143135249","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 : 2025-02-04DOI: 10.1016/j.apcata.2025.120152
Anna Gagliardi , Agustín de Arriba , María J. Vallejo , Daniel Delgado , Jesús López-Sánchez , Tommaso Tabanelli , Juan Rubio-Zuazo , Fabrizio Cavani , José M. López Nieto
While bioethanol has been acknowledged as a relevant bioderived feedstock, acetaldehyde is an important commodity used to produce a variety of industrial chemicals, and its manufacture currently relies almost exclusively on fossil ethylene. This paper shows the effect of Cs-content in W-V-O hexagonal tungsten bronze catalysts on changes in both the physicochemical characteristics of catalysts and their catalytic performance in the aerobic transformation of ethanol to acetaldehyde, providing a promising pathway to broaden the domain of biorefinery products. The catalytic results were explained on the basis of the elimination of acid sites (responsible to the formation of ethylene and diethyl ether) by the incorporation of Cs+, as interstitial cations, in V-containing hexagonal tungsten bronzes. The catalysts were characterized by XRD, IR, XPS and FESEM, among others, and the incorporation of Cs+ into the bronze backbone, successfully demonstrated by HAXPES and confocal Raman techniques, led to 33 % EtOH conversion and 97 % acetaldehyde selectivity in the best catalyst’s formulation.
{"title":"Synthesis of Cs-W-V-O hexagonal tungsten bronzes for the partial oxidation of ethanol to acetaldehyde","authors":"Anna Gagliardi , Agustín de Arriba , María J. Vallejo , Daniel Delgado , Jesús López-Sánchez , Tommaso Tabanelli , Juan Rubio-Zuazo , Fabrizio Cavani , José M. López Nieto","doi":"10.1016/j.apcata.2025.120152","DOIUrl":"10.1016/j.apcata.2025.120152","url":null,"abstract":"<div><div>While bioethanol has been acknowledged as a relevant bioderived feedstock, acetaldehyde is an important commodity used to produce a variety of industrial chemicals, and its manufacture currently relies almost exclusively on fossil ethylene. This paper shows the effect of Cs-content in W-V-O hexagonal tungsten bronze catalysts on changes in both the physicochemical characteristics of catalysts and their catalytic performance in the aerobic transformation of ethanol to acetaldehyde, providing a promising pathway to broaden the domain of biorefinery products. The catalytic results were explained on the basis of the elimination of acid sites (responsible to the formation of ethylene and diethyl ether) by the incorporation of Cs<sup>+</sup>, as interstitial cations, in V-containing hexagonal tungsten bronzes. The catalysts were characterized by XRD, IR, XPS and FESEM, among others, and the incorporation of Cs<sup>+</sup> into the bronze backbone, successfully demonstrated by HAXPES and confocal Raman techniques, led to 33 % EtOH conversion and 97 % acetaldehyde selectivity in the best catalyst’s formulation.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"694 ","pages":"Article 120152"},"PeriodicalIF":4.7,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143350070","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}
Catalytic cracking of naphtha to produce olefins using ZSM-5 can fulfill the growing demand for light olefins and the energy problem. In the current work, vanadium oxide in different supports was mixed with ZSM-5 as a tandem catalyst for oxidative cracking of n-hexane to light olefins. The results showed that adding vanadium as a tandem catalyst with ZSM-5 increased n-hexane conversion to 68.8 % for VOx/Al2O3 and 86.7 % for VOx/SiO2 addition. Selectivity to light olefin was significantly changed due to the oxidative dehydrogenation reaction in the vanadium active site. The position and proximity of the metal oxide and acid sites determine the reaction pathway and product distribution. A stability test showed that the conversion of n-hexane decreased from 58 % to 37 %. Still, the selectivity to olefin was stable at 60 % due to the carbon formation blocking the acid site, not the metal oxide sites.
{"title":"Enhanced catalytic cracking of n-hexane cracking to olefin via rational design of tandem vanadium oxide-based catalyst on ZSM-5","authors":"Ariel Hazril Gursida , Yahya Gambo , Shaikh Abdur Razzak , Mohammad Mozahar Hossain","doi":"10.1016/j.apcata.2025.120149","DOIUrl":"10.1016/j.apcata.2025.120149","url":null,"abstract":"<div><div>Catalytic cracking of naphtha to produce olefins using ZSM-5 can fulfill the growing demand for light olefins and the energy problem. In the current work, vanadium oxide in different supports was mixed with ZSM-5 as a tandem catalyst for oxidative cracking of n-hexane to light olefins. The results showed that adding vanadium as a tandem catalyst with ZSM-5 increased n-hexane conversion to 68.8 % for VOx/Al<sub>2</sub>O<sub>3</sub> and 86.7 % for VOx/SiO<sub>2</sub> addition. Selectivity to light olefin was significantly changed due to the oxidative dehydrogenation reaction in the vanadium active site. The position and proximity of the metal oxide and acid sites determine the reaction pathway and product distribution. A stability test showed that the conversion of n-hexane decreased from 58 % to 37 %. Still, the selectivity to olefin was stable at 60 % due to the carbon formation blocking the acid site, not the metal oxide sites.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"694 ","pages":"Article 120149"},"PeriodicalIF":4.7,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369448","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}
Ni-Zr0.92Y0.16O2.08(YSZ)-supported solid oxide cell with La0.9Sr0.1Ga0.8Mg0.2O3-δ(LSGM) thin film as the electrolyte was prepared with dip-coating and co-sintering methods. CO2/H2O co-electrolysis and CO2 electrolysis performance were studied. Initial performance measurement from 1073 to 773 K shows reasonably high open circuit voltage (OCV) with superior current densities, particularly in CO2/H2O co-electrolysis, up to −4.9 A/cm2 at 1073 K and −0.19 A/cm2 at 773 K. Product analysis suggests that H2 and CO production was attributed to both electrolysis and the reverse water-gas shift (RWGS) reaction, with almost 100 % Faraday efficiency. The H2/CO ratio in the product ranged from 1.4 to 1.5 in co-electrolysis when CO2/H2O= 1/1 gas was fed. Performance comparison at 1073 K indicated that direct CO2 electrolysis occurred, however, steam electrolysis predominately occurred under co-electrolysis conditions. The prepared cell shows good stability at −0.1 A/cm2 under CO2/H2O co-electrolysis for 200 h, with almost no change in terminal potential with minimal degradation.
{"title":"Planer type solid oxide cells using La0.9Sr0.1Ga0.8Mg0.2O3-δ thin-film electrolyte prepared by dip-coating method for high performance CO2/H2O co-electrolysis","authors":"Longtai Li , Motonori Watanabe , Miki Inada , Tatsumi Ishihara","doi":"10.1016/j.apcata.2025.120146","DOIUrl":"10.1016/j.apcata.2025.120146","url":null,"abstract":"<div><div>Ni-Zr<sub>0.92</sub>Y<sub>0.16</sub>O<sub>2.08</sub>(YSZ)-supported solid oxide cell with La<sub>0.9</sub>Sr<sub>0.1</sub>Ga<sub>0.8</sub>Mg<sub>0.2</sub>O<sub>3-δ</sub>(LSGM) thin film as the electrolyte was prepared with dip-coating and co-sintering methods. CO<sub>2</sub>/H<sub>2</sub>O co-electrolysis and CO<sub>2</sub> electrolysis performance were studied. Initial performance measurement from 1073 to 773 K shows reasonably high open circuit voltage (OCV) with superior current densities, particularly in CO<sub>2</sub>/H<sub>2</sub>O co-electrolysis, up to −4.9 A/cm<sup>2</sup> at 1073 K and −0.19 A/cm<sup>2</sup> at 773 K. Product analysis suggests that H<sub>2</sub> and CO production was attributed to both electrolysis and the reverse water-gas shift (RWGS) reaction, with almost 100 % Faraday efficiency. The H<sub>2</sub>/CO ratio in the product ranged from 1.4 to 1.5 in co-electrolysis when CO<sub>2</sub>/H<sub>2</sub>O= 1/1 gas was fed. Performance comparison at 1073 K indicated that direct CO<sub>2</sub> electrolysis occurred, however, steam electrolysis predominately occurred under co-electrolysis conditions. The prepared cell shows good stability at −0.1 A/cm<sup>2</sup> under CO<sub>2</sub>/H<sub>2</sub>O co-electrolysis for 200 h, with almost no change in terminal potential with minimal degradation.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"694 ","pages":"Article 120146"},"PeriodicalIF":4.7,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143369449","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 : 2025-01-30DOI: 10.1016/j.apcata.2025.120148
Min Ouyang , Shaoyu Kong , Wei Cao , Dongxue Zhang, Feipeng Zheng, Xiaobo Chen
A large challenge in hydrogen electrocatalysis is the great decrease in catalytic activity of noble metals when moving from acidic electrolytes to basic ones. Based on first-principles calculations, we report that the Pt/electrolyte interface undergoes a transformation from a highly mobile hydrogen-bond network of water in acid to a solid-state and rigid Na-OH ionic-bond framework in base. Meanwhile, the hydrogen coverage decreases from 100 % to 16 %. This transformation leads to a barrierless water dissociation process, challenging the traditional belief that water splitting is the primary obstacle. The solid-state NaOH layer impedes proton migration towards the interface and retards hydrogen desorption, resulting in the sluggish kinetics. Incorporation of Ni atoms at the interface builds a proton transfer channel through the NaOH layer, enhancing the proton transfer kinetics. We suggest that electron-donor dopants can enhance the kinetics of both the interfacial reactions and the proton transfer in solution.
{"title":"Rigid Na-OH ionic-bond framework in the Helmholtz layer induces the kinetic pH effect in hydrogen electrocatalysis on Pt","authors":"Min Ouyang , Shaoyu Kong , Wei Cao , Dongxue Zhang, Feipeng Zheng, Xiaobo Chen","doi":"10.1016/j.apcata.2025.120148","DOIUrl":"10.1016/j.apcata.2025.120148","url":null,"abstract":"<div><div>A large challenge in hydrogen electrocatalysis is the great decrease in catalytic activity of noble metals when moving from acidic electrolytes to basic ones. Based on first-principles calculations, we report that the Pt/electrolyte interface undergoes a transformation from a highly mobile hydrogen-bond network of water in acid to a solid-state and rigid Na-OH ionic-bond framework in base. Meanwhile, the hydrogen coverage decreases from 100 % to 16 %. This transformation leads to a barrierless water dissociation process, challenging the traditional belief that water splitting is the primary obstacle. The solid-state NaOH layer impedes proton migration towards the interface and retards hydrogen desorption, resulting in the sluggish kinetics. Incorporation of Ni atoms at the interface builds a proton transfer channel through the NaOH layer, enhancing the proton transfer kinetics. We suggest that electron-donor dopants can enhance the kinetics of both the interfacial reactions and the proton transfer in solution.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"694 ","pages":"Article 120148"},"PeriodicalIF":4.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143162744","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 : 2025-01-30DOI: 10.1016/j.apcata.2025.120147
Shikai Wang , Yafan Wang , Fei Zha , Xiaohua Tang , Yue Chang , Haifeng Tian
The decomposition of 1,3-diisopropylbenzene dihydroperoxide (DHP) obtained by the catalytic oxidation of 1,3-diisopropylbenzene (DIPB) is known as the main industrial process to produce resorcinol. A new catalyst of highly dispersed Fe in P-doped N-C (Fe-N/P-C) was synthesized using a ligand-assisted method, and was applied for the peroxidation of DIPB. SEM, TEM and HAADF-STEM revealed that Fe is uniformly dispersed on N/P-C. XRD, Raman spectra, N2 adsorption/desorption, XPS and O2-TPD showed that doping of P species in N-C leads to form more mesopore and increases the disorder degree, providing more active sites for the activation of tertiary C-H bonds in DIPB. The conversion of DIPB was 97.8 % and the yield of DHP was 67.2 % under mass of Fe-N/P-C to DIPB was 1.0, reaction temperature was 90°C, oxygen flow rate was 100 mL/min, and reaction time was 8 h. The investigation of radical quenching and mass spectrometry suggested that the increased oxidation rate is attributed to the involvement of Fe-N/P-C in both chain initiation and chain propagation.
{"title":"Highly dispersed Fe in P dopped N-C for the catalytic peroxidation of 1,3-diisopropylbenzene with molecular oxygen","authors":"Shikai Wang , Yafan Wang , Fei Zha , Xiaohua Tang , Yue Chang , Haifeng Tian","doi":"10.1016/j.apcata.2025.120147","DOIUrl":"10.1016/j.apcata.2025.120147","url":null,"abstract":"<div><div>The decomposition of 1,3-diisopropylbenzene dihydroperoxide (DHP) obtained by the catalytic oxidation of 1,3-diisopropylbenzene (DIPB) is known as the main industrial process to produce resorcinol. A new catalyst of highly dispersed Fe in P-doped N-C (Fe-N/P-C) was synthesized using a ligand-assisted method, and was applied for the peroxidation of DIPB. SEM, TEM and HAADF-STEM revealed that Fe is uniformly dispersed on N/P-C. XRD, Raman spectra, N<sub>2</sub> adsorption/desorption, XPS and O<sub>2</sub>-TPD showed that doping of P species in N-C leads to form more mesopore and increases the disorder degree, providing more active sites for the activation of tertiary C-H bonds in DIPB. The conversion of DIPB was 97.8 % and the yield of DHP was 67.2 % under mass of Fe-N/P-C to DIPB was 1.0, reaction temperature was 90°C, oxygen flow rate was 100 mL/min, and reaction time was 8 h. The investigation of radical quenching and mass spectrometry suggested that the increased oxidation rate is attributed to the involvement of Fe-N/P-C in both chain initiation and chain propagation.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"694 ","pages":"Article 120147"},"PeriodicalIF":4.7,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143378049","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}
Electrocatalytic CO2 reduction reaction (CO2RR) to multi-carbon product, especially for ethylene (C2H4), provides a favorable pathway for carbon neutrality and renewable energy storage. However, the second-order C-C coupling reactions in CO2RR need always the high activation/driven energy in dynamics originating from the trace C1 intermediate product. Herein, we synthesized the Ag-decorated Cu2O porous hollow core-shell catalyst named Ag@Cu2O where Ag nanoparticles uniformly distributed on inner the surface of the hollow Cu2O (H-Cu2O) via the sacrificial template method. Benefiting from the synergistic hollow structure and electron transfer from Cu and Ag to O, Ag@Cu2O catalyst delivers the excellent C2H4 Faradaic Efficiency (FE) of 55 % ± 2 % at −1.0 V (vs. RHE), which is superior to the most reported catalysts. More importantly, in situ infrared spectroscopy and density functional theory (DFT) calculations reveal the introduction of Ag can decrease the activation energy required for *CO and C-C coupling.
{"title":"Ag-decorated Cu2O porous hollow catalyst for promoting CO2 electroreduction to C2H4 via enrichment of CO","authors":"Jianhao Li, Zhicheng Hu, Shuhuan Han, Dapeng Cao, Xiaofei Zeng, Jianfeng Chen","doi":"10.1016/j.apcata.2025.120145","DOIUrl":"10.1016/j.apcata.2025.120145","url":null,"abstract":"<div><div>Electrocatalytic CO<sub>2</sub> reduction reaction (CO<sub>2</sub>RR) to multi-carbon product, especially for ethylene (C<sub>2</sub>H<sub>4</sub>), provides a favorable pathway for carbon neutrality and renewable energy storage. However, the second-order C-C coupling reactions in CO<sub>2</sub>RR need always the high activation/driven energy in dynamics originating from the trace C<sub>1</sub> intermediate product. Herein, we synthesized the Ag-decorated Cu<sub>2</sub>O porous hollow core-shell catalyst named Ag@Cu<sub>2</sub>O where Ag nanoparticles uniformly distributed on inner the surface of the hollow Cu<sub>2</sub>O (H-Cu<sub>2</sub>O) via the sacrificial template method. Benefiting from the synergistic hollow structure and electron transfer from Cu and Ag to O, Ag@Cu<sub>2</sub>O catalyst delivers the excellent C<sub>2</sub>H<sub>4</sub> Faradaic Efficiency (FE) of 55 % ± 2 % at −1.0 V (vs. RHE), which is superior to the most reported catalysts. More importantly, in situ infrared spectroscopy and density functional theory (DFT) calculations reveal the introduction of Ag can decrease the activation energy required for *CO and C-C coupling.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"694 ","pages":"Article 120145"},"PeriodicalIF":4.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143163857","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}
RuO2/CeO2–ZrO2 (Ru/CZ) shows high activity for soot oxidation in a NO2/O2 flow. The soot oxidation occurred at the soot-Ru/CZ interface and at the soot surface. It was shown that RuO2 increases the Ce3 +/Ce in CZ surface, and that dissociates the adsorbed O2 and supplies O atoms to CZ support. Adsorbed-NO3 (ad-NO3) contributed more than gaseous NO2 to soot oxidation. The investigation of activation energy and outlet NOx gas suggested that ad-NO3 ignited soot, and then CZ lattice oxygen and reactive oxygen species derived from CZ support mainly oxidized soot. Although the molar ratio of ad-NO3/soot was only 1 %, ad-NO3 accelerated soot oxidation. This was implied to be because ad-NO3 oxidizes soot through the redox cycle between ad-NO2 and ad-NO3 by CZ lattice oxygen. Soot oxidation over Ru/CZ is believed to be accelerated by the synergistic effect of the O2 dissociation by RuO2 and the ignition of soot by ad-NO3.
{"title":"Roles of NOx and the supported RuO2 in accelerating soot oxidation over RuO2/CeO2–ZrO2","authors":"Hitoshi Kubo , Yusuke Ohshima , Shunsuke Kato , Noriyuki Saitoh , Noriko Yoshizawa , Osamu Nakagoe , Shuji Tanabe","doi":"10.1016/j.apcata.2025.120144","DOIUrl":"10.1016/j.apcata.2025.120144","url":null,"abstract":"<div><div>RuO<sub>2</sub>/CeO<sub>2</sub>–ZrO<sub>2</sub> (Ru/CZ) shows high activity for soot oxidation in a NO<sub>2</sub>/O<sub>2</sub> flow. The soot oxidation occurred at the soot-Ru/CZ interface and at the soot surface. It was shown that RuO<sub>2</sub> increases the Ce<sup>3 +</sup>/Ce in CZ surface, and that dissociates the adsorbed O<sub>2</sub> and supplies O atoms to CZ support. Adsorbed-NO<sub>3</sub> (ad-NO<sub>3</sub>) contributed more than gaseous NO<sub>2</sub> to soot oxidation. The investigation of activation energy and outlet NO<sub>x</sub> gas suggested that ad-NO<sub>3</sub> ignited soot, and then CZ lattice oxygen and reactive oxygen species derived from CZ support mainly oxidized soot. Although the molar ratio of ad-NO<sub>3</sub>/soot was only 1 %, ad-NO<sub>3</sub> accelerated soot oxidation. This was implied to be because ad-NO<sub>3</sub> oxidizes soot through the redox cycle between ad-NO<sub>2</sub> and ad-NO<sub>3</sub> by CZ lattice oxygen. Soot oxidation over Ru/CZ is believed to be accelerated by the synergistic effect of the O<sub>2</sub> dissociation by RuO<sub>2</sub> and the ignition of soot by ad-NO<sub>3</sub>.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"693 ","pages":"Article 120144"},"PeriodicalIF":4.7,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099824","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 : 2025-01-27DOI: 10.1016/j.apcata.2025.120143
Sheng Bi , Qiangwei Li , Le-Cheng Wang , Xiao-Feng Wu
Based on the idea of environmental protection and sustainable development, the developing of new procedure for the chemical conversion of plastics and related chemicals into value-added chemicals are always attractive. In this context, we designed a photocatalytic reaction that employs 4-alkyl-1,4-dihydropyridines (alkyl-DHP) and arylamines to degrade and transform formaldehyde polymers. This innovative process effectively degrades paraformaldehyde and polyoxymethylene plastic, yielding a series of amine products in satisfactory quantities. This new procedure unveils a new strategy for the chemical degradation of plastics.
{"title":"Photo-driven metal-free radical addition reaction for the degradation of formaldehyde polymers","authors":"Sheng Bi , Qiangwei Li , Le-Cheng Wang , Xiao-Feng Wu","doi":"10.1016/j.apcata.2025.120143","DOIUrl":"10.1016/j.apcata.2025.120143","url":null,"abstract":"<div><div>Based on the idea of environmental protection and sustainable development, the developing of new procedure for the chemical conversion of plastics and related chemicals into value-added chemicals are always attractive. In this context, we designed a photocatalytic reaction that employs 4-alkyl-1,4-dihydropyridines (alkyl-DHP) and arylamines to degrade and transform formaldehyde polymers. This innovative process effectively degrades paraformaldehyde and polyoxymethylene plastic, yielding a series of amine products in satisfactory quantities. This new procedure unveils a new strategy for the chemical degradation of plastics.</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"693 ","pages":"Article 120143"},"PeriodicalIF":4.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099873","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 : 2025-01-27DOI: 10.1016/j.apcata.2025.120141
Sriram Mansingh , Kundan Kumar Das , Ritik Mohanty , Newmoon Priyadarshini, Kulamani Parida
H2O2 production by utilizing renewable feedstocks like solar energy, H2O and O2 through artificial photocatalysis is an intriguing area of sustainable research. Porous and defect-oriented g-C3N4 is a promising metal free material for photon driven H2O2 generation via. O2/H2O redox pathway because of its benefitting features. The designed vacancy-oriented carbon nitride with amorphous character along with inverse opal type framework boost the overall O2 reduction rate and on-situ gemifloxacine (GFM) degradation. The PCN sample manifest the optimum peroxide generation (587 µmol/g/h and conversion efficiency of 0.011 %) which is 1.4 times higher than CN. The photoreduction goes predominantly via. both single electron two step, i.e., ●O2- radical route confirms by scavenger and EPR test. Further, reduction reaction was also evaluated under different reaction condition, i.e., pH, sacrificial agent and purging gas type. Besides, PCN depicts enhanced onsite photo-fenton GFM degradation (78 % in 1 h) and the formed intermediates species alongside the mineralization 70 % is well demonstrated. This investigation serves as a guideline for the development of different amorphous and defect based photocatalysts for sustainable H2O2 generation and on-site photo-fenton activity with benchmark efficiency
{"title":"Inverse opal type porous g-C3N4 towards H2O2 production and in-situ photoFenton gemifloxacin degradation driven by amorphous framework and nitrogen vacancy","authors":"Sriram Mansingh , Kundan Kumar Das , Ritik Mohanty , Newmoon Priyadarshini, Kulamani Parida","doi":"10.1016/j.apcata.2025.120141","DOIUrl":"10.1016/j.apcata.2025.120141","url":null,"abstract":"<div><div>H<sub>2</sub>O<sub>2</sub> production by utilizing renewable feedstocks like solar energy, H<sub>2</sub>O and O<sub>2</sub> through artificial photocatalysis is an intriguing area of sustainable research. Porous and defect-oriented g-C<sub>3</sub>N<sub>4</sub> is a promising metal free material for photon driven H<sub>2</sub>O<sub>2</sub> generation via. O<sub>2</sub>/H<sub>2</sub>O redox pathway because of its benefitting features. The designed vacancy-oriented carbon nitride with amorphous character along with inverse opal type framework boost the overall O2 reduction rate and on-situ gemifloxacine (GFM) degradation. The PCN sample manifest the optimum peroxide generation (587 µmol/g/h and conversion efficiency of 0.011 %) which is 1.4 times higher than CN. The photoreduction goes predominantly via. both single electron two step, i.e., <sup>●</sup>O<sub>2</sub><sup>-</sup> radical route confirms by scavenger and EPR test. Further, reduction reaction was also evaluated under different reaction condition, i.e., pH, sacrificial agent and purging gas type. Besides, PCN depicts enhanced onsite photo-fenton GFM degradation (78 % in 1 h) and the formed intermediates species alongside the mineralization 70 % is well demonstrated. This investigation serves as a guideline for the development of different amorphous and defect based photocatalysts for sustainable H<sub>2</sub>O<sub>2</sub> generation and on-site photo-fenton activity with benchmark efficiency</div></div>","PeriodicalId":243,"journal":{"name":"Applied Catalysis A: General","volume":"693 ","pages":"Article 120141"},"PeriodicalIF":4.7,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143099823","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}
扫码关注我们
求助内容：
应助结果提醒方式：
京公网安备 11010802042870号