Pub Date : 2024-11-28DOI: 10.1016/j.cattod.2024.115143
Lin Gao , Zixian Jia , Lijiao Qin , Haocheng Sun , Xinwei Zhang , Baozhong Li , Xuehai Wang , Jiquan Liu , Jinbo Bai
The recovery of Zn/ZnO nanoparticles from spent alkaline batteries was studied. This catalyst was employed for glycolysis of polyethylene terephthalate (PET) to produce bis(2-hydroxyethyl) terephthalate (BHET). The reaction temperature, catalyst/PET ratio and reaction time were investigated. Under the optimal conditions of 190 ℃ and 2 hours, with a catalyst/PET ratio of 2 %, the PET conversion rate and BHET yield of this process were 99 % and 81 %, respectively. The experimental results show that the catalyst exhibits high catalytic activity, is easy to separate, and has good reusability. In addition, this catalyst can deal effectively with impurities and dyes present in waste PET. Finally glycolysis kinetic studies were conducted on the reaction of PET degradation, and the activation energy of 118.8 kJ·mol−1 were obtained.
{"title":"Using waste to treat waste: Catalysts from spent alkaline batteries for glycolysis of PET waste","authors":"Lin Gao , Zixian Jia , Lijiao Qin , Haocheng Sun , Xinwei Zhang , Baozhong Li , Xuehai Wang , Jiquan Liu , Jinbo Bai","doi":"10.1016/j.cattod.2024.115143","DOIUrl":"10.1016/j.cattod.2024.115143","url":null,"abstract":"<div><div>The recovery of Zn/ZnO nanoparticles from spent alkaline batteries was studied. This catalyst was employed for glycolysis of polyethylene terephthalate (PET) to produce bis(2-hydroxyethyl) terephthalate (BHET). The reaction temperature, catalyst/PET ratio and reaction time were investigated. Under the optimal conditions of 190 ℃ and 2 hours, with a catalyst/PET ratio of 2 %, the PET conversion rate and BHET yield of this process were 99 % and 81 %, respectively. The experimental results show that the catalyst exhibits high catalytic activity, is easy to separate, and has good reusability. In addition, this catalyst can deal effectively with impurities and dyes present in waste PET. Finally glycolysis kinetic studies were conducted on the reaction of PET degradation, and the activation energy of 118.8 kJ·mol<sup>−1</sup> were obtained.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"447 ","pages":"Article 115143"},"PeriodicalIF":5.2,"publicationDate":"2024-11-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748445","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 : 2024-11-25DOI: 10.1016/j.cattod.2024.115145
Jiamin Wang , Shanhui Zhu , Zexiang Lv , Xiangyu Jia , Xiaoming Li , Mei Dong , Weibin Fan
Selective cleavage of C–O bond in biomass-derived furfuryl alcohol (FFA), with complex chemical functional groups, poses a great challenge to biomass upgrading. In this work, Pt/Mg2AlO catalysts were prepared by urea hydrolysis (Pt-HT), coprecipitation (Pt-CP) and sol-gel (Pt-SG) methods to study the interfacial property caused by support synthesis methods during selective hydrogenation of FFA to 1,2-pentanediol (1,2-PeD). The results clearly showed that 1,2-PeD yield on Pt-HT was 60.3 %, better than those on Pt-CP and Pt-SG catalysts. The superior catalytic activity of Pt-HT is ascribed to effective adsorption and split of C–O bonds, facilitated by plentiful interfacial oxygen vacancies and Pt0 species. Furthermore, the superior selectivity of 1,2-PeD is related to the deforming non-parallel adsorption mode of FFA rings on Pt-HT resulting from their interaction with interfacial oxygen vacancies.
{"title":"Selective hydrogenation of furfuryl alcohol to 1,2-pentanediol over Pt/Mg2AlO catalysts with different synthesis methods","authors":"Jiamin Wang , Shanhui Zhu , Zexiang Lv , Xiangyu Jia , Xiaoming Li , Mei Dong , Weibin Fan","doi":"10.1016/j.cattod.2024.115145","DOIUrl":"10.1016/j.cattod.2024.115145","url":null,"abstract":"<div><div>Selective cleavage of C–O bond in biomass-derived furfuryl alcohol (FFA), with complex chemical functional groups, poses a great challenge to biomass upgrading. In this work, Pt/Mg<sub>2</sub>AlO catalysts were prepared by urea hydrolysis (Pt-HT), coprecipitation (Pt-CP) and sol-gel (Pt-SG) methods to study the interfacial property caused by support synthesis methods during selective hydrogenation of FFA to 1,2-pentanediol (1,2-PeD). The results clearly showed that 1,2-PeD yield on Pt-HT was 60.3 %, better than those on Pt-CP and Pt-SG catalysts. The superior catalytic activity of Pt-HT is ascribed to effective adsorption and split of C–O bonds, facilitated by plentiful interfacial oxygen vacancies and Pt<sup>0</sup> species. Furthermore, the superior selectivity of 1,2-PeD is related to the deforming non-parallel adsorption mode of FFA rings on Pt-HT resulting from their interaction with interfacial oxygen vacancies.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"447 ","pages":"Article 115145"},"PeriodicalIF":5.2,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142748447","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 : 2024-11-22DOI: 10.1016/j.cattod.2024.115134
Katiúscia M. Nobre Borba , Letícia Guerreiro da Trindade , Letícia Zanchet , Sibele Pergher , Urbano Diaz , Fernando Rey Garcia , Katia Bernardo-Gusmão
The use of MCM-41 led to the development of a silylated hybrid material (MS), which in turn played a crucial role in obtaining semiconducting polyphenylacetylene, with a conductivity of 8.13 × 10−5 S m−1. MS was also responsible for reducing the polyphenylacetylene band gap from 2.13 eV to 1.83 eV. When used in a capacitor, polyphenylacetylene exhibited stability after 3000 charge/discharge cycles and a capacitance seven times higher than that of poly(o-methoxyaniline) (POMA) polymer.
{"title":"Novel preparation of polyphenylacetylene semiconductor: Potential application in supercapacitors","authors":"Katiúscia M. Nobre Borba , Letícia Guerreiro da Trindade , Letícia Zanchet , Sibele Pergher , Urbano Diaz , Fernando Rey Garcia , Katia Bernardo-Gusmão","doi":"10.1016/j.cattod.2024.115134","DOIUrl":"10.1016/j.cattod.2024.115134","url":null,"abstract":"<div><div>The use of MCM-41 led to the development of a silylated hybrid material (MS), which in turn played a crucial role in obtaining semiconducting polyphenylacetylene, with a conductivity of 8.13 × 10<sup>−5</sup> S m<sup>−1</sup>. MS was also responsible for reducing the polyphenylacetylene band gap from 2.13 eV to 1.83 eV. When used in a capacitor, polyphenylacetylene exhibited stability after 3000 charge/discharge cycles and a capacitance seven times higher than that of poly(o-methoxyaniline) (POMA) polymer.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"447 ","pages":"Article 115134"},"PeriodicalIF":5.2,"publicationDate":"2024-11-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142757804","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}
We present a systematic theoretical study on the applicability of the hybrid Cun-TiO2 systems (n = 1 – 7) for photo electrochemical hydrogen evolution reaction. The preferred binding sites for hydrogen atom are determined. The hydrogen adopts a Cu-H-Ti bridging position when bound to Cu1-(TiO2)34 or Cu7-(TiO2)34 or Cu-H-Cu when bound to Cu2-(TiO2)34 or Cu4-(TiO2)34. In Cun-(TiO2)34 with n = 3, 5, 6 the H atom sits in the three coordinate site, similar to that found for its favourable position while on Cu(111). The population analysis reveals that in the selected cases, n = 1, 2, 5, 7, the hydrogen binding exhibits three centre two electron bond character. In all the cases studied here the adsorbate has a hydride character. Among the studied clusters, those containing 1, 4, and 7 copper atoms exhibit moderate Gibbs free H binding energies indicating them as the best candidates for hydrogen evolution. The obtained results are compared with data available in literature for metallic copper and other materials having isolated single Cu atom sites. Considering Cu atom efficiency as well as wide availability and use of the titania as a support, these materials may be competitive for H2 generation.
{"title":"Single atom and sub-nanometer copper clusters deposited on titania for hydrogen evolution reaction: A density functional study","authors":"Dorota Rutkowska-Zbik , Vidya Kaipanchery , Renata Tokarz-Sobieraj","doi":"10.1016/j.cattod.2024.115142","DOIUrl":"10.1016/j.cattod.2024.115142","url":null,"abstract":"<div><div>We present a systematic theoretical study on the applicability of the hybrid Cu<sub>n</sub>-TiO<sub>2</sub> systems (n = 1 – 7) for photo electrochemical hydrogen evolution reaction. The preferred binding sites for hydrogen atom are determined. The hydrogen adopts a Cu-H-Ti bridging position when bound to Cu<sub>1</sub>-(TiO<sub>2</sub>)<sub>34</sub> or Cu<sub>7</sub>-(TiO<sub>2</sub>)<sub>34</sub> or Cu-H-Cu when bound to Cu<sub>2</sub>-(TiO<sub>2</sub>)<sub>34</sub> or Cu<sub>4</sub>-(TiO<sub>2</sub>)<sub>34</sub>. In Cu<sub>n</sub>-(TiO<sub>2</sub>)<sub>34</sub> with n = 3, 5, 6 the H atom sits in the three coordinate site, similar to that found for its favourable position while on Cu(111). The population analysis reveals that in the selected cases, n = 1, 2, 5, 7, the hydrogen binding exhibits three centre two electron bond character. In all the cases studied here the adsorbate has a hydride character. Among the studied clusters, those containing 1, 4, and 7 copper atoms exhibit moderate Gibbs free H binding energies indicating them as the best candidates for hydrogen evolution. The obtained results are compared with data available in literature for metallic copper and other materials having isolated single Cu atom sites. Considering Cu atom efficiency as well as wide availability and use of the titania as a support, these materials may be competitive for H<sub>2</sub> generation.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"446 ","pages":"Article 115142"},"PeriodicalIF":5.2,"publicationDate":"2024-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700422","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 : 2024-11-20DOI: 10.1016/j.cattod.2024.115141
Kelly C.N.R. Pedro , Gabrielle A.R. da Silva , Mônica A.P. da Silva , Cristiane A. Henriques , Marta A.P. Langone
Lipases have been immobilized on various supports to catalyze hydrolysis, esterification, and transesterification reactions efficiently. Among a broad range of materials, mesoporous silica has attracted attention thanks to its distinct characteristics and advantages, being widely used for biocatalysis applications. In this work, the lipase from Thermomyces lanuginosus (TLL) was immobilized on six different carriers: two zeolites HZSM-5 (SAR 25 and 280), mesoporous Si-MCM-41, and silica-aluminas Siral 10, 20, and 40. TLL was efficiently immobilized in Siral 20 (99.9 %) and Siral 40 (99.9 %) using 26 mg g−1 of enzyme loading. Due to its more hydrophobic nature, Siral 40 was selected as the most suitable support for TLL immobilization using 5 mmol L−1 of sodium phosphate buffer solution, pH 7, and rotational stirring as the optimum condition. The effect of protein concentration on the TLL immobilization was investigated, and the results adjusted well (R2 > 0.99) on the Langmuir isotherm model. The Siral 40 presented a maximum adsorption capacity equal to 169 mgprotein gsupport−1. The heterogeneous biocatalyst (TLL-S40) was applied in biodiesel synthesis, olive oil hydrolysis, p-nitrophenyl-laurate hydrolysis, and ethyl oleate synthesis. The esterification reaction was successfully catalyzed by TLL-S40, leading to a conversion 2.6-fold higher than free TLL at 30 °C. The biocatalyst was reused for three operational cycles with a retention of 34 % of its initial conversion. The results show that Siral 40, a silica-alumina material, can potentially be employed in lipase immobilization for esterification reactions.
{"title":"Immobilization of lipase on zeolite, silica, and silica-aluminas and its use in hydrolysis, esterification, and transesterification reactions","authors":"Kelly C.N.R. Pedro , Gabrielle A.R. da Silva , Mônica A.P. da Silva , Cristiane A. Henriques , Marta A.P. Langone","doi":"10.1016/j.cattod.2024.115141","DOIUrl":"10.1016/j.cattod.2024.115141","url":null,"abstract":"<div><div>Lipases have been immobilized on various supports to catalyze hydrolysis, esterification, and transesterification reactions efficiently. Among a broad range of materials, mesoporous silica has attracted attention thanks to its distinct characteristics and advantages, being widely used for biocatalysis applications. In this work, the lipase from <em>Thermomyces lanuginosus</em> (TLL) was immobilized on six different carriers: two zeolites HZSM-5 (SAR 25 and 280), mesoporous Si-MCM-41, and silica-aluminas Siral 10, 20, and 40. TLL was efficiently immobilized in Siral 20 (99.9 %) and Siral 40 (99.9 %) using 26 mg g<sup>−1</sup> of enzyme loading. Due to its more hydrophobic nature, Siral 40 was selected as the most suitable support for TLL immobilization using 5 mmol L<sup>−1</sup> of sodium phosphate buffer solution, pH 7, and rotational stirring as the optimum condition. The effect of protein concentration on the TLL immobilization was investigated, and the results adjusted well (R<sup>2</sup> > 0.99) on the Langmuir isotherm model. The Siral 40 presented a maximum adsorption capacity equal to 169 mg<sub>protein</sub> g<sub>support</sub><sup>−1</sup>. The heterogeneous biocatalyst (TLL-S40) was applied in biodiesel synthesis, olive oil hydrolysis, <em>p</em>-nitrophenyl-laurate hydrolysis, and ethyl oleate synthesis. The esterification reaction was successfully catalyzed by TLL-S40, leading to a conversion 2.6-fold higher than free TLL at 30 °C. The biocatalyst was reused for three operational cycles with a retention of 34 % of its initial conversion. The results show that Siral 40, a silica-alumina material, can potentially be employed in lipase immobilization for esterification reactions.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"447 ","pages":"Article 115141"},"PeriodicalIF":5.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702910","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 : 2024-11-20DOI: 10.1016/j.cattod.2024.115138
Bhagyesha S. Patil , Alejandra Torres-Velasco , Hashim A. Alzahrani , Skylar Pratt , Juan J. Bravo-Suárez
Tungsten based catalysts supported on silica (zWOX/SiO2) and silica promoted by titania (zWOX/yTiOX/SiO2) were studied for their catalytic activity towards propylene metathesis. The catalysts were prepared by a simple incipient wetness impregnation method using a large pore SiO2 of intermediate surface area (∼50 m2/g). Catalytic activity studies carried out in a fixed-bed reactor (723 K, 101 kPa propylene) indicated that propylene conversion increased with increasing W loading in zWOx/SiO2 catalysts (z = 0.5−6 W/nm2). It was shown that the catalytic activity of a poorly WOX dispersed 6WOX/SiO2 catalyst could be enhanced and maximized by an optimum titania promotion of 2 wt% TiO2 (∼3 Ti/nm2). In situ differential diffuse reflectance (DDR) UV-Vis spectroscopy at reaction conditions showed that TiOX domain size increased with increases in titania loading from isolated TiOX to TiOX clusters to TiO2 nanocrystals. The UV-Vis results also evidenced the existence of highly dispersed isolated WOX species, WOX clusters, and WO3 nanoparticles in the 6WOX/yTiOX/SiO2 (y = 0.5−6 wt% TiO2 or ∼0.7–9 Ti/nm2) catalysts. In situ DDR-UV-Vis, Raman, and mass spectrometry during propylene metathesis, and catalyst oxidation and reduction revealed the reasons for an optimum amount of titania promoter in 6WOX/2TiOX/SiO2. They were the result of a balanced interplay between two factors: (1) enhanced WOx species dispersion due to the presence of a trimeric TiOX cluster and (2) absence of catalyst deactivation (present at high TiO2 loadings) due to the trimeric TiOX cluster poor reactivity towards coke formation.
{"title":"In Situ DDR-UV-Vis and Raman spectroscopic study of titania promoting effect on silica supported tungsten catalysts for enhanced propylene metathesis","authors":"Bhagyesha S. Patil , Alejandra Torres-Velasco , Hashim A. Alzahrani , Skylar Pratt , Juan J. Bravo-Suárez","doi":"10.1016/j.cattod.2024.115138","DOIUrl":"10.1016/j.cattod.2024.115138","url":null,"abstract":"<div><div>Tungsten based catalysts supported on silica (<em>z</em>WO<sub>X</sub>/SiO<sub>2</sub>) and silica promoted by titania (<em>z</em>WO<sub>X</sub>/<em>y</em>TiO<sub>X</sub>/SiO<sub>2</sub>) were studied for their catalytic activity towards propylene metathesis. The catalysts were prepared by a simple incipient wetness impregnation method using a large pore SiO<sub>2</sub> of intermediate surface area (∼50 m<sup>2</sup>/g). Catalytic activity studies carried out in a fixed-bed reactor (723 K, 101 kPa propylene) indicated that propylene conversion increased with increasing W loading in <em>z</em>WOx/SiO<sub>2</sub> catalysts (<em>z</em> = 0.5−6 W/nm<sup>2</sup>). It was shown that the catalytic activity of a poorly WO<sub>X</sub> dispersed 6WO<sub>X</sub>/SiO<sub>2</sub> catalyst could be enhanced and maximized by an optimum titania promotion of 2 wt% TiO<sub>2</sub> (∼3 Ti/nm<sup>2</sup>). In situ differential diffuse reflectance (DDR) UV-Vis spectroscopy at reaction conditions showed that TiO<sub>X</sub> domain size increased with increases in titania loading from isolated TiO<sub>X</sub> to TiO<sub>X</sub> clusters to TiO<sub>2</sub> nanocrystals. The UV-Vis results also evidenced the existence of highly dispersed isolated WO<sub>X</sub> species, WO<sub>X</sub> clusters, and WO<sub>3</sub> nanoparticles in the 6WO<sub>X</sub>/<em>y</em>TiO<sub>X</sub>/SiO<sub>2</sub> (<em>y</em> = 0.5−6 wt% TiO<sub>2</sub> or ∼0.7–9 Ti/nm<sup>2</sup>) catalysts. In situ DDR-UV-Vis, Raman, and mass spectrometry during propylene metathesis, and catalyst oxidation and reduction revealed the reasons for an optimum amount of titania promoter in 6WO<sub>X</sub>/2TiO<sub>X</sub>/SiO<sub>2</sub>. They were the result of a balanced interplay between two factors: (1) enhanced WOx species dispersion due to the presence of a trimeric TiO<sub>X</sub> cluster and (2) absence of catalyst deactivation (present at high TiO<sub>2</sub> loadings) due to the trimeric TiO<sub>X</sub> cluster poor reactivity towards coke formation.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"447 ","pages":"Article 115138"},"PeriodicalIF":5.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142724093","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 : 2024-11-20DOI: 10.1016/j.cattod.2024.115140
Suelen Martins Stutz Gomes, Samara da Silva Montani, Luz Amparo Palacio, Fatima Maria Zanon Zotin
Three-way automotive catalysts (TWC) are based on noble metals and have two significant limitations: high cost and tendency to form, at low temperatures, nitrous oxide (N2O), which contributes to the greenhouse effect and ozone layer depletion. Thus, it is crucial to study possible substitutes for these components. In this work, catalysts prepared from copper and aluminum hydrotalcite-like materials impregnated with potassium were studied. The formation of the hydrotalcite phase and CuO phase in the catalyst was evidenced by X-ray diffraction (XRD). Temperature-programmed reduction (TPR) results showed that the alkali metal positively influences the reducibility of the catalyst, decreasing its reduction temperature. Temperature-programmed desorption (TPD) analysis revealed electronic promotion, confirming that the presence of potassium facilitates the desorption of molecular nitrogen from the surface and decreases that of N2O. Catalytic tests showed differences in the behavior of the catalysts depending on the pretreatment performed, suggesting that the interaction between potassium and oxidized or reduced copper gives rise to different catalytic sites. The formation of oxygen vacancies in potassium-containing catalysts, identified by XPS, and the increase in the copper metal surface area contributed to explaining the better performance of these catalysts. Also, based on the catalytic tests, more selective catalysts with the addition of potassium (minimizing N2O formation) were obtained, especially at a ratio of 0.025 K/Cu (mol/mol) and after a reducing pretreatment. This catalyst also showed 100 % N2O conversion in the reduction by CO at temperatures close to 100 °C, confirming its excellent performance in nitrous oxide abatement.
{"title":"Performance of copper-aluminum catalysts impregnated with potassium in NO and N2O reduction by CO","authors":"Suelen Martins Stutz Gomes, Samara da Silva Montani, Luz Amparo Palacio, Fatima Maria Zanon Zotin","doi":"10.1016/j.cattod.2024.115140","DOIUrl":"10.1016/j.cattod.2024.115140","url":null,"abstract":"<div><div>Three-way automotive catalysts (TWC) are based on noble metals and have two significant limitations: high cost and tendency to form, at low temperatures, nitrous oxide (N<sub>2</sub>O), which contributes to the greenhouse effect and ozone layer depletion. Thus, it is crucial to study possible substitutes for these components. In this work, catalysts prepared from copper and aluminum hydrotalcite-like materials impregnated with potassium were studied. The formation of the hydrotalcite phase and CuO phase in the catalyst was evidenced by X-ray diffraction (XRD). Temperature-programmed reduction (TPR) results showed that the alkali metal positively influences the reducibility of the catalyst, decreasing its reduction temperature. Temperature-programmed desorption (TPD) analysis revealed electronic promotion, confirming that the presence of potassium facilitates the desorption of molecular nitrogen from the surface and decreases that of N<sub>2</sub>O. Catalytic tests showed differences in the behavior of the catalysts depending on the pretreatment performed, suggesting that the interaction between potassium and oxidized or reduced copper gives rise to different catalytic sites. The formation of oxygen vacancies in potassium-containing catalysts, identified by XPS, and the increase in the copper metal surface area contributed to explaining the better performance of these catalysts. Also, based on the catalytic tests, more selective catalysts with the addition of potassium (minimizing N<sub>2</sub>O formation) were obtained, especially at a ratio of 0.025 K/Cu (mol/mol) and after a reducing pretreatment. This catalyst also showed 100 % N<sub>2</sub>O conversion in the reduction by CO at temperatures close to 100 °C, confirming its excellent performance in nitrous oxide abatement.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"447 ","pages":"Article 115140"},"PeriodicalIF":5.2,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142702909","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 : 2024-11-19DOI: 10.1016/j.cattod.2024.115139
Marina Aliste , Lixy Olinda León-Morán , Carmen María Martínez-Escudero , Isabel Garrido , Fulgencio Contreras , Pilar Hellín , Pilar Flores , José Fenoll
In recent years, solar photo-Fenton (SPF) processes have gained interest owing to the use of a cost-free and sustainable radiation source and their effectiveness in removing pharmaceuticals, among other Emerging Pollutants (EPs), from wastewater. Especially, when iron complexes are used to work at neutral pH. The stability and biodegradability characteristics make ethylenediamine-N,N-disuccinic acid (EDDS), and nitrilotriacetic acid (NTA) suitable iron complexing agents. In this work, the removal of diclofenac (DCF) and ibuprofen (IBU), two of the most widely used Non-steroidal Anti-Inflammatory Drug (NSAID) for the treatment of pain, at 200 µg L−1 was studied in wastewater using SPF at natural pH, comparing EDDS and NTA as chelating agents for the first time. The main transformation products (TPs) were also monitored. For this purpose, a suitable analytical method using liquid chromatography coupled to triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) with Electro Spray Ionization negative mode (ESI-) was applied to determine the pharmaceutical EPs and their main TPs in wastewater. Next, they were confirmed by LC-QTOF-HRMS. DCF was degraded 44 % faster with NTA (t1/2 53 min) than with EDDS (t1/2 77 min), although the final removal percentages, including photolysis, were similar (90–93 %). In contrast, IBU removal with EDDS (t1/2 116 min) was twice as fast as with NTA (t1/2 231 min), whereas photolysis was ineffective. Twenty TPs were monitored, of which only three were detected because of the low concentration used in this study: DCF-2C (m/z 258.0326), DCF-6B (m/z 310.0040), and IBU-4 (m/z 221.1181). Their behaviour followed a formation-elimination profile, but only the complete oxidation of DCF-6 was achieved. This work focuses on the kinetic aspects and TPs formed, which are useful for improving knowledge for the development of efficient processes to abate organic pollutants in real aqueous matrices. Therefore, more EPs should be thoroughly studied to determine the efficiency of EDDS and NTA as iron-chelating agents and the necessity of implementing the SPF process in WWTPs.
{"title":"Solar photo-Fenton with Fe3+-EDDS and Fe3+-NTA at neutral pH for removal of ibuprofen, diclofenac and their main transformation products in wastewater","authors":"Marina Aliste , Lixy Olinda León-Morán , Carmen María Martínez-Escudero , Isabel Garrido , Fulgencio Contreras , Pilar Hellín , Pilar Flores , José Fenoll","doi":"10.1016/j.cattod.2024.115139","DOIUrl":"10.1016/j.cattod.2024.115139","url":null,"abstract":"<div><div>In recent years, solar photo-Fenton (SPF) processes have gained interest owing to the use of a cost-free and sustainable radiation source and their effectiveness in removing pharmaceuticals, among other Emerging Pollutants (EPs), from wastewater. Especially, when iron complexes are used to work at neutral pH. The stability and biodegradability characteristics make ethylenediamine-N,N-disuccinic acid (EDDS), and nitrilotriacetic acid (NTA) suitable iron complexing agents. In this work, the removal of diclofenac (DCF) and ibuprofen (IBU), two of the most widely used Non-steroidal Anti-Inflammatory Drug (NSAID) for the treatment of pain, at 200 µg L<sup>−1</sup> was studied in wastewater using SPF at natural pH, comparing EDDS and NTA as chelating agents for the first time. The main transformation products (TPs) were also monitored. For this purpose, a suitable analytical method using liquid chromatography coupled to triple quadrupole tandem mass spectrometry (LC-QqQ-MS/MS) with Electro Spray Ionization negative mode (ESI<sup>-</sup>) was applied to determine the pharmaceutical EPs and their main TPs in wastewater. Next, they were confirmed by LC-QTOF-HRMS. DCF was degraded 44 % faster with NTA (t<sub>1/2</sub> 53 min) than with EDDS (t<sub>1/2</sub> 77 min), although the final removal percentages, including photolysis, were similar (90–93 %). In contrast, IBU removal with EDDS (t<sub>1/2</sub> 116 min) was twice as fast as with NTA (t<sub>1/2</sub> 231 min), whereas photolysis was ineffective. Twenty TPs were monitored, of which only three were detected because of the low concentration used in this study: DCF-2C (<em>m/z</em> 258.0326), DCF-6B (<em>m/z</em> 310.0040), and IBU-4 (<em>m/z</em> 221.1181). Their behaviour followed a formation-elimination profile, but only the complete oxidation of DCF-6 was achieved. This work focuses on the kinetic aspects and TPs formed, which are useful for improving knowledge for the development of efficient processes to abate organic pollutants in real aqueous matrices. Therefore, more EPs should be thoroughly studied to determine the efficiency of EDDS and NTA as iron-chelating agents and the necessity of implementing the SPF process in WWTPs.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"446 ","pages":"Article 115139"},"PeriodicalIF":5.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700411","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 : 2024-11-19DOI: 10.1016/j.cattod.2024.115137
Annalisa Polo , Chiara Nomellini , Gianluigi Marra , Elena Selli , Maria Vittoria Dozzi
An effective strategy to boost the photoelectrochemical (PEC) performance of photoactive materials consists in combining different semiconductors with complementary characteristics, to build type-II heterojunctions. In particular, WO3/BiVO4 photoanodes exhibit synergistic effects in the photo-oxidation of water into molecular oxygen, usually overwhelming possible recombination paths at work within the heterojunction. We present here a systematic PEC investigation on composite WO3/BiVO4 photoanodes with various WO3 and BiVO4 layer thickness (200–800 nm and 40–140 nm, respectively), in comparison with equally thick single WO3 and BiVO4 photoanodes, performed under either solar or monochromatic irradiation. We demonstrate that detrimental charge recombination is mainly active under back-side irradiation and is mitigated by minimizing the absorption of both tungsten trioxide and bismuth vanadate layers. Higher photocurrent values are in general attained when the photoanodes are irradiated through the electrolyte/electrode interface, with the best performing photoanodes being composed of ca. 500 nm- and 140 nm-thick WO3 and BiVO4 layers, respectively.
{"title":"WO3/BiVO4 heterojunction photoanodes: Optimized photoelectrochemical performance in relation to both oxides layer thickness","authors":"Annalisa Polo , Chiara Nomellini , Gianluigi Marra , Elena Selli , Maria Vittoria Dozzi","doi":"10.1016/j.cattod.2024.115137","DOIUrl":"10.1016/j.cattod.2024.115137","url":null,"abstract":"<div><div>An effective strategy to boost the photoelectrochemical (PEC) performance of photoactive materials consists in combining different semiconductors with complementary characteristics, to build type-II heterojunctions. In particular, WO<sub>3</sub>/BiVO<sub>4</sub> photoanodes exhibit synergistic effects in the photo-oxidation of water into molecular oxygen, usually overwhelming possible recombination paths at work within the heterojunction. We present here a systematic PEC investigation on composite WO<sub>3</sub>/BiVO<sub>4</sub> photoanodes with various WO<sub>3</sub> and BiVO<sub>4</sub> layer thickness (200–800 nm and 40–140 nm, respectively), in comparison with equally thick single WO<sub>3</sub> and BiVO<sub>4</sub> photoanodes, performed under either solar or monochromatic irradiation. We demonstrate that detrimental charge recombination is mainly active under back-side irradiation and is mitigated by minimizing the absorption of both tungsten trioxide and bismuth vanadate layers. Higher photocurrent values are in general attained when the photoanodes are irradiated through the electrolyte/electrode interface, with the best performing photoanodes being composed of <em>ca.</em> 500 nm- and 140 nm-thick WO<sub>3</sub> and BiVO<sub>4</sub> layers, respectively.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"446 ","pages":"Article 115137"},"PeriodicalIF":5.2,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142700410","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The paper reports on the use of heterogeneous supported Cu catalysts in the aqueous phase reduction of mono and disaccharides to reduced sugars. The huge availability of the starting materials present also in many side streams of the agri-food industry and the growing interest in polyols not only in the food and pharma sectors but also in the polymer one make this reaction a relevant one in the current scenario. Although less active than Ru and Ni based ones, low loaded Cu catalysts show very interesting performance. Conversions up to 100 % can be reached in the hydrogenation of galactose at 160°C and 40 bar of H2. Moreover, they allow to directly obtain reduced sugars in the hydrogenation of disaccharides through a one pot bifunctional hydrolysis-hydrogenation process. The high dispersion of the Cu metallic phase and the presence of weak acidic sites on the catalyst surface can give account of the observed activity and selectivity.
{"title":"The peculiar role of copper in the saccharides hydrogenation in aqueous phase","authors":"Federica Zaccheria , Léa Vilcocq , Valeria Pappalardo , Nicola Scotti , Nicoletta Ravasio","doi":"10.1016/j.cattod.2024.115135","DOIUrl":"10.1016/j.cattod.2024.115135","url":null,"abstract":"<div><div>The paper reports on the use of heterogeneous supported Cu catalysts in the aqueous phase reduction of mono and disaccharides to reduced sugars. The huge availability of the starting materials present also in many side streams of the agri-food industry and the growing interest in polyols not only in the food and pharma sectors but also in the polymer one make this reaction a relevant one in the current scenario. Although less active than Ru and Ni based ones, low loaded Cu catalysts show very interesting performance. Conversions up to 100 % can be reached in the hydrogenation of galactose at 160°C and 40 bar of H<sub>2</sub>. Moreover, they allow to directly obtain reduced sugars in the hydrogenation of disaccharides through a one pot bifunctional hydrolysis-hydrogenation process. The high dispersion of the Cu metallic phase and the presence of weak acidic sites on the catalyst surface can give account of the observed activity and selectivity.</div></div>","PeriodicalId":264,"journal":{"name":"Catalysis Today","volume":"446 ","pages":"Article 115135"},"PeriodicalIF":5.2,"publicationDate":"2024-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658791","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}
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