Qaisar Maqbool, Hamilton Uchenna Aharanwa, Michael Stöger-Pollach, Günther Rupprechter
Transforming hazardous and difficult-to-process waste materials, like spent Ni-MH batteries and aluminium foil, into nanocatalysts (NCts) provides a sustainable solution for resource management and reducing environmental impact. This study demonstrates a novel approach by extracting nickel sulfate (NiSO4·xH2O) from battery waste and subsequently converting it into Ni(OH)2 hydrogel precursors using l-glutamic acid. Waste aluminium foil was processed into alumina (Al2O3), and combined with Ni(OH)2 to synthesize Ni/η-Al2O3 NCts with 4% and 8% Ni loading. Characterization through XRD/SAED, STEM/EFTEM, and EELS revealed a disordered cubic structure of η-Al2O3, with well-dispersed Ni particles, making it effective for CO2 hydrogenation. The 8-Ni/η-Al2O3 exhibited the best catalytic performance, with CH4 selectivity of 99.8% and space time yield (STY) of 80.3 mmolCH4 gcat-1 h-1 at 400 °C. The CO2 methanation mechanism over Ni/η-Al2O3 NCts was further explored using operando DRIFTS aligned with GC + MS. The operando investigation suggested a preferential associative CO2 methanation pathway, involving sequential adsorption and hydrogenation of CO2 to hydrogen carbonates on Ni/η-Al2O3, and their transformation into formate and methoxy intermediates leading to methane. Finally, to complete the upcycling/recycling loop, the spent Ni/η-Al2O3 NCts were recycled into Ni and Al precursors. These findings underscore the potential of upcycling waste materials for synthesizing sustainable, high-performance NCts, and offer insights into the CO2 methanation mechanism.
{"title":"Upcycling hazardous waste into high-performance Ni/η-Al<sub>2</sub>O<sub>3</sub> catalysts for CO<sub>2</sub> methanation.","authors":"Qaisar Maqbool, Hamilton Uchenna Aharanwa, Michael Stöger-Pollach, Günther Rupprechter","doi":"10.1039/d4gc05217j","DOIUrl":"https://doi.org/10.1039/d4gc05217j","url":null,"abstract":"<p><p>Transforming hazardous and difficult-to-process waste materials, like spent Ni-MH batteries and aluminium foil, into nanocatalysts (NCts) provides a sustainable solution for resource management and reducing environmental impact. This study demonstrates a novel approach by extracting nickel sulfate (NiSO<sub>4</sub>·<i>x</i>H<sub>2</sub>O) from battery waste and subsequently converting it into Ni(OH)<sub>2</sub> hydrogel precursors using l-glutamic acid. Waste aluminium foil was processed into alumina (Al<sub>2</sub>O<sub>3</sub>), and combined with Ni(OH)<sub>2</sub> to synthesize Ni/η-Al<sub>2</sub>O<sub>3</sub> NCts with 4% and 8% Ni loading. Characterization through XRD/SAED, STEM/EFTEM, and EELS revealed a disordered cubic structure of η-Al<sub>2</sub>O<sub>3</sub>, with well-dispersed Ni particles, making it effective for CO<sub>2</sub> hydrogenation. The 8-Ni/η-Al<sub>2</sub>O<sub>3</sub> exhibited the best catalytic performance, with CH<sub>4</sub> selectivity of 99.8% and space time yield (STY) of 80.3 mmol<sub>CH<sub>4</sub></sub> g<sub>cat</sub> <sup>-1</sup> h<sup>-1</sup> at 400 °C. The CO<sub>2</sub> methanation mechanism over Ni/η-Al<sub>2</sub>O<sub>3</sub> NCts was further explored using <i>operando</i> DRIFTS aligned with GC + MS. The <i>operando</i> investigation suggested a preferential associative CO<sub>2</sub> methanation pathway, involving sequential adsorption and hydrogenation of CO<sub>2</sub> to hydrogen carbonates on Ni/η-Al<sub>2</sub>O<sub>3</sub>, and their transformation into formate and methoxy intermediates leading to methane. Finally, to complete the upcycling/recycling loop, the spent Ni/η-Al<sub>2</sub>O<sub>3</sub> NCts were recycled into Ni and Al precursors. These findings underscore the potential of upcycling waste materials for synthesizing sustainable, high-performance NCts, and offer insights into the CO<sub>2</sub> methanation mechanism.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" ","pages":""},"PeriodicalIF":9.3,"publicationDate":"2025-02-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11826383/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143432054","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Mohsen Siahkamari, Debkumar Debnath, Tuo Wang and Mojgan Nejad
This study investigates the synthesis and characterization of lignin-formaldehyde (LF) and fully biobased lignin-glyoxal (LG) resins as alternatives to the phenol-formaldehyde (PF) adhesive currently used in the manufacturing of plywood and oriented strand boards (OSB). In this process, phenol was entirely replaced by a commercially available kraft-softwood lignin, while formaldehyde was substituted with glyoxal (a biobased dialdehyde) in the LG resins. Additionally, lignin monomers were used as model compounds to better understand the behavior of lignin in LF and LG resins. The reactions of phenol, lignin monomers, and commercial lignin with formaldehyde and glyoxal were investigated through Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy in both solution and solid states. The results confirmed the successful integration of formaldehyde and glyoxal into phenolic structures, leading to the formation of methylene and glyoxylene linkages during resin synthesis. This process created a robust three-dimensional network, as evidenced by 2D 13C–13C correlation solid-state NMR spectra and FT-IR analyses, which are crucial in studying the structural properties of the cured thermoset solid resins that are insoluble in NMR solvents. These findings highlight the innovative potential of lignin as a renewable alternative to petroleum-based phenol and emphasize the practical applications of a fully biobased lignin-glyoxal adhesive in the production of greener, more sustainable, and formaldehyde-free plywood and OSB wood panels commonly used in building construction.
{"title":"A fundamental study of lignin reactions with formaldehyde and glyoxal†","authors":"Mohsen Siahkamari, Debkumar Debnath, Tuo Wang and Mojgan Nejad","doi":"10.1039/D4GC05695G","DOIUrl":"https://doi.org/10.1039/D4GC05695G","url":null,"abstract":"<p >This study investigates the synthesis and characterization of lignin-formaldehyde (LF) and fully biobased lignin-glyoxal (LG) resins as alternatives to the phenol-formaldehyde (PF) adhesive currently used in the manufacturing of plywood and oriented strand boards (OSB). In this process, phenol was entirely replaced by a commercially available kraft-softwood lignin, while formaldehyde was substituted with glyoxal (a biobased dialdehyde) in the LG resins. Additionally, lignin monomers were used as model compounds to better understand the behavior of lignin in LF and LG resins. The reactions of phenol, lignin monomers, and commercial lignin with formaldehyde and glyoxal were investigated through Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopy in both solution and solid states. The results confirmed the successful integration of formaldehyde and glyoxal into phenolic structures, leading to the formation of methylene and glyoxylene linkages during resin synthesis. This process created a robust three-dimensional network, as evidenced by 2D <small><sup>13</sup></small>C–<small><sup>13</sup></small>C correlation solid-state NMR spectra and FT-IR analyses, which are crucial in studying the structural properties of the cured thermoset solid resins that are insoluble in NMR solvents. These findings highlight the innovative potential of lignin as a renewable alternative to petroleum-based phenol and emphasize the practical applications of a fully biobased lignin-glyoxal adhesive in the production of greener, more sustainable, and formaldehyde-free plywood and OSB wood panels commonly used in building construction.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2342-2358"},"PeriodicalIF":9.3,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/gc/d4gc05695g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430744","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
We present here a high-efficiency, eco-friendly method for synthesizing alkyl fluorides (15 min, 50–89% yields) through halogen exchange, utilizing simple and readily available alkyl halides as starting materials. This catalyst-free method employs AgF as the fluorine source, operates under ball milling conditions, demonstrates broad functional group compatibility, and has found application in the synthesis of key intermediates for the marketed drug ledipasvir.
{"title":"Mechanochemical fluorination of unactivated tertiary alkyl chlorides†","authors":"Jiemin Wang, Xueyan Yang, Cheng Peng, Mengyao Pei and Xiaofeng Wei","doi":"10.1039/D4GC05972G","DOIUrl":"https://doi.org/10.1039/D4GC05972G","url":null,"abstract":"<p >We present here a high-efficiency, eco-friendly method for synthesizing alkyl fluorides (15 min, 50–89% yields) through halogen exchange, utilizing simple and readily available alkyl halides as starting materials. This catalyst-free method employs AgF as the fluorine source, operates under ball milling conditions, demonstrates broad functional group compatibility, and has found application in the synthesis of key intermediates for the marketed drug ledipasvir.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2197-2202"},"PeriodicalIF":9.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430724","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Sanrunyi Gong, Tianzhen Li, Zijing Tang, Zijian Tan, Ruke Zhang, Karsten Olsen, Haifeng Liu and Leilei Zhu
Here, we report an enzymatic cascade reaction converting a high concentration of formaldehyde into L-threitol. The cascade reaction starts with the carboligation of formaldehyde catalyzed by formolase and fructose-6-phosphate aldolase, generating L-erythrulose. Subsequently, a newly identified L-threitol dehydrogenase facilitates the conversion of L-erythrulose into L-threitol, utilizing NADH as a coenzyme. Three types of NADH regeneration systems were investigated to facilitate the recycling of NADH in the reaction system. 405.7 mM (49.6 g L−1) L-threitol was achieved from the conversion of formaldehyde in a one-pot reaction system with a self-sufficient NADH recycling system, which is based on the oxidation of glycerol catalyzed by glycerol dehydrogenase. Furthermore, the highest yield (89.4%; 251.3 mM) of L-threitol from formaldehyde was achieved in the one-pot two-step reaction system in which NADH was efficiently recycled by using methanol dehydrogenase and isopropanol.
{"title":"One-pot enzymatic synthesis of l-threitol from C1 formaldehyde†","authors":"Sanrunyi Gong, Tianzhen Li, Zijing Tang, Zijian Tan, Ruke Zhang, Karsten Olsen, Haifeng Liu and Leilei Zhu","doi":"10.1039/D4GC05638H","DOIUrl":"https://doi.org/10.1039/D4GC05638H","url":null,"abstract":"<p >Here, we report an enzymatic cascade reaction converting a high concentration of formaldehyde into <small>L</small>-threitol. The cascade reaction starts with the carboligation of formaldehyde catalyzed by formolase and fructose-6-phosphate aldolase, generating <small>L</small>-erythrulose. Subsequently, a newly identified <small>L</small>-threitol dehydrogenase facilitates the conversion of <small>L</small>-erythrulose into <small>L</small>-threitol, utilizing NADH as a coenzyme. Three types of NADH regeneration systems were investigated to facilitate the recycling of NADH in the reaction system. 405.7 mM (49.6 g L<small><sup>−1</sup></small>) <small>L</small>-threitol was achieved from the conversion of formaldehyde in a one-pot reaction system with a self-sufficient NADH recycling system, which is based on the oxidation of glycerol catalyzed by glycerol dehydrogenase. Furthermore, the highest yield (89.4%; 251.3 mM) of <small>L</small>-threitol from formaldehyde was achieved in the one-pot two-step reaction system in which NADH was efficiently recycled by using methanol dehydrogenase and isopropanol.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2189-2196"},"PeriodicalIF":9.3,"publicationDate":"2025-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430723","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Patrícia Pereira, Phillip E. Savage and Christian W. Pester
Correction for ‘Acid catalyst screening for hydrolysis of post-consumer PET waste and exploration of acidolysis’ by Patrícia Pereira et al., Green Chem., 2024, 26, 1964–1974, https://doi.org/10.1039/D3GC03906D.
{"title":"Correction: Acid catalyst screening for hydrolysis of post-consumer PET waste and exploration of acidolysis","authors":"Patrícia Pereira, Phillip E. Savage and Christian W. Pester","doi":"10.1039/D5GC90017D","DOIUrl":"https://doi.org/10.1039/D5GC90017D","url":null,"abstract":"<p >Correction for ‘Acid catalyst screening for hydrolysis of post-consumer PET waste and exploration of acidolysis’ by Patrícia Pereira <em>et al.</em>, <em>Green Chem.</em>, 2024, <strong>26</strong>, 1964–1974, https://doi.org/10.1039/D3GC03906D.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 7","pages":" 2165-2166"},"PeriodicalIF":9.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/gc/d5gc90017d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143373156","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Guowen Zhou, Yunfeng Zhou, Xiaoqian Zhang, Zepeng Lei and Xiaohui Wang
Castor oil-based waterborne polyurethanes (CWPUs) are recognized as sustainable polymers sourced from renewable materials. However, these polymers often exhibit suboptimal mechanical properties and lack reprocessability due to their soft backbones and irreversible crosslinking structures. Herein, we synthesized a novel rigid diol (VSD) featuring dynamic acylhydrazone covalent bonds, which remain stable even in aqueous environments and can contribute additional hydrogen bonding sites, through the condensation reaction of commercially available succinohydrazide with lignin-derived vanillin. VSD was subsequently introduced into the CWPU system to form colorless and transparent CWPU-VSD films, which exhibited self-healable and reprocessable properties due to the dynamic nature of the acylhydrazone bond. By adjusting the ratio of VSD (the ‘hard’ section) to castor oil (the ‘soft’ section), the mechanical properties of CWPU-VSDs were finely tuned, achieving an optimal tensile strength of 33.9 MPa. Moreover, the application of this CWPU as a paper-based functional coating was explored. The coated paper exhibited excellent water and oil resistances, low water vapor permeability, good recyclability and biodegradability, suggesting a promising approach for the development of multifunctional and sustainable paper-based barrier coatings.
{"title":"High-strength, self-healable, transparent castor-oil-based waterborne polyurethane barrier coatings enabled by a dynamic acylhydrazone co-monomer†","authors":"Guowen Zhou, Yunfeng Zhou, Xiaoqian Zhang, Zepeng Lei and Xiaohui Wang","doi":"10.1039/D4GC06103A","DOIUrl":"https://doi.org/10.1039/D4GC06103A","url":null,"abstract":"<p >Castor oil-based waterborne polyurethanes (CWPUs) are recognized as sustainable polymers sourced from renewable materials. However, these polymers often exhibit suboptimal mechanical properties and lack reprocessability due to their soft backbones and irreversible crosslinking structures. Herein, we synthesized a novel rigid diol (VSD) featuring dynamic acylhydrazone covalent bonds, which remain stable even in aqueous environments and can contribute additional hydrogen bonding sites, through the condensation reaction of commercially available succinohydrazide with lignin-derived vanillin. VSD was subsequently introduced into the CWPU system to form colorless and transparent CWPU-VSD films, which exhibited self-healable and reprocessable properties due to the dynamic nature of the acylhydrazone bond. By adjusting the ratio of VSD (the ‘hard’ section) to castor oil (the ‘soft’ section), the mechanical properties of CWPU-VSDs were finely tuned, achieving an optimal tensile strength of 33.9 MPa. Moreover, the application of this CWPU as a paper-based functional coating was explored. The coated paper exhibited excellent water and oil resistances, low water vapor permeability, good recyclability and biodegradability, suggesting a promising approach for the development of multifunctional and sustainable paper-based barrier coatings.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2220-2229"},"PeriodicalIF":9.3,"publicationDate":"2025-01-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430726","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Shanshan Liu, Jia Wan, Yaoyao Zhang, Wen-Yu Luo, Weiwei Dong, Chao Wang and Lin-Yu Jiao
We developed an Fe–Ru/γ-Al2O3 relay catalyst to promote the multi-component reaction of biomass derived α-hydroxy acids and 2,5-dimethoxytetrahydrofuran with 2-nitroaromatic amines, enabling the synthesis of quinoxalines from inexpensive starting materials in one step. In this strategy, α-hydroxy acids displayed multifunctional roles as a hydrogen source, carbon synthon, and acidic additive. Notably, industrial grade lactic acid and mixed α-hydroxy acids extracted from fruits could be directly used and converted into a normalized quinoxaline product. Significantly, practical synthesis from glucose or fruits and successive transformation into a twisted-intramolecular charge transfer (TICT) based luminogen were accomplished nicely. Mechanistic studies showed that the equilibrium of the dehydrogenation step was promoted through tandem hydrogenation and cyclization reactions. Our work demonstrates the feasibility of chemical transformation of crude bio-based α-hydroxy acids into N-heterocycles and opens the way to provide high-value luminescent materials from biomass.
{"title":"A supported Fe/Ru catalyzed three-component relay reaction through a hydrogen borrowing strategy: conversion of crude α-hydroxy acids into valuable N-heterocycles†","authors":"Shanshan Liu, Jia Wan, Yaoyao Zhang, Wen-Yu Luo, Weiwei Dong, Chao Wang and Lin-Yu Jiao","doi":"10.1039/D4GC05518G","DOIUrl":"https://doi.org/10.1039/D4GC05518G","url":null,"abstract":"<p >We developed an Fe–Ru/γ-Al<small><sub>2</sub></small>O<small><sub>3</sub></small> relay catalyst to promote the multi-component reaction of biomass derived α-hydroxy acids and 2,5-dimethoxytetrahydrofuran with 2-nitroaromatic amines, enabling the synthesis of quinoxalines from inexpensive starting materials in one step. In this strategy, α-hydroxy acids displayed multifunctional roles as a hydrogen source, carbon synthon, and acidic additive. Notably, industrial grade lactic acid and mixed α-hydroxy acids extracted from fruits could be directly used and converted into a normalized quinoxaline product. Significantly, practical synthesis from glucose or fruits and successive transformation into a twisted-intramolecular charge transfer (TICT) based luminogen were accomplished nicely. Mechanistic studies showed that the equilibrium of the dehydrogenation step was promoted through tandem hydrogenation and cyclization reactions. Our work demonstrates the feasibility of chemical transformation of crude bio-based α-hydroxy acids into N-heterocycles and opens the way to provide high-value luminescent materials from biomass.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2293-2301"},"PeriodicalIF":9.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430736","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Stephan Sarner, Norbert H. Menzler, Jürgen Malzbender, Martin Hilger, Doris Sebold, André Weber and Olivier Guillon
The solid oxide cell (SOC) technology relies on high-performance ceramics containing strategically valuable and critical raw materials. This study focuses on the processing of spent cell materials from fuel-electrode-supported SOCs, demonstrating the feasibility of utilizing a significant portion of the ceramic cell in a closed-loop system. More than 85% of the cell's initial mass was directly incorporated into substrate manufacturing. The air-side perovskites were initially separated using hydrochloric acid treatment, followed by mechanical reprocessing of the remaining half cells. The performance of the resulting full cells containing 50 mass% recycled material in the substrate was evaluated, achieving a current density of up to 1.14 A cm−2 at 0.7 V and 750 °C in fuel cell mode, which is comparable to that of non-recycled counterparts. Preliminary experiments for the recovery of leached metal ions from the air electrode were conducted using direct oxalate precipitation while examining pH dependence. Direct oxalate precipitation proved particularly effective in the low pH range for the recovery of a lanthanum oxalate precursor with a purity exceeding 98%. The results highlight the potential for simple and sustainable practices in SOC technology.
{"title":"Towards a scalable recycling process for ceramics in fuel-electrode-supported solid oxide cells†","authors":"Stephan Sarner, Norbert H. Menzler, Jürgen Malzbender, Martin Hilger, Doris Sebold, André Weber and Olivier Guillon","doi":"10.1039/D4GC05883F","DOIUrl":"https://doi.org/10.1039/D4GC05883F","url":null,"abstract":"<p >The solid oxide cell (SOC) technology relies on high-performance ceramics containing strategically valuable and critical raw materials. This study focuses on the processing of spent cell materials from fuel-electrode-supported SOCs, demonstrating the feasibility of utilizing a significant portion of the ceramic cell in a closed-loop system. More than 85% of the cell's initial mass was directly incorporated into substrate manufacturing. The air-side perovskites were initially separated using hydrochloric acid treatment, followed by mechanical reprocessing of the remaining half cells. The performance of the resulting full cells containing 50 mass% recycled material in the substrate was evaluated, achieving a current density of up to 1.14 A cm<small><sup>−2</sup></small> at 0.7 V and 750 °C in fuel cell mode, which is comparable to that of non-recycled counterparts. Preliminary experiments for the recovery of leached metal ions from the air electrode were conducted using direct oxalate precipitation while examining pH dependence. Direct oxalate precipitation proved particularly effective in the low pH range for the recovery of a lanthanum oxalate precursor with a purity exceeding 98%. The results highlight the potential for simple and sustainable practices in SOC technology.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2252-2262"},"PeriodicalIF":9.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/gc/d4gc05883f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pu Chen, Lin Tian, Lindong Xiao, Xiaochen Ji, Guo-Jun Deng and Huawen Huang
The involvement of transition metals and radicals in the selective difunctionalization of conjugated dienes has proved to be one of the practical strategies for the rapid synthesis of promising allylic compounds. Herein, we report a protocol for copper-catalyzed 1,2-dioxygenation of 1,3-dienes with tert-butyl benzoperoxoate (TBPB) at room temperature. This strategy features mild reaction conditions, excellent atom economy, and good regio- and chemoselectivity, providing a straightforward and efficient approach for the synthesis of allyl esters. In particular, this free-radical double C–O bonding process can be carried out in the aqueous phase and the first attempts on asymmetric synthesis have been made to obtain modest to good enantioselectivity. Mechanistic studies have demonstrated that the SET process of the Cu(I) catalyst with TBPB and the generation of allyl radical intermediates are essential for the successful conduct of this difunctionalization ploy.
{"title":"Copper-catalyzed 1,2-dioxygenation of 1,3-dienes with tert-butyl benzoperoxoate at room temperature†","authors":"Pu Chen, Lin Tian, Lindong Xiao, Xiaochen Ji, Guo-Jun Deng and Huawen Huang","doi":"10.1039/D4GC05378H","DOIUrl":"https://doi.org/10.1039/D4GC05378H","url":null,"abstract":"<p >The involvement of transition metals and radicals in the selective difunctionalization of conjugated dienes has proved to be one of the practical strategies for the rapid synthesis of promising allylic compounds. Herein, we report a protocol for copper-catalyzed 1,2-dioxygenation of 1,3-dienes with <em>tert</em>-butyl benzoperoxoate (TBPB) at room temperature. This strategy features mild reaction conditions, excellent atom economy, and good regio- and chemoselectivity, providing a straightforward and efficient approach for the synthesis of allyl esters. In particular, this free-radical double C–O bonding process can be carried out in the aqueous phase and the first attempts on asymmetric synthesis have been made to obtain modest to good enantioselectivity. Mechanistic studies have demonstrated that the SET process of the Cu(<small>I</small>) catalyst with TBPB and the generation of allyl radical intermediates are essential for the successful conduct of this difunctionalization ploy.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2302-2308"},"PeriodicalIF":9.3,"publicationDate":"2025-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430740","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Ang Gao, He-Xiang Liu, Ya-Nan Zhou and Ming-Chen Fu
We present a catalyst- and thiol-free protocol for arene C–H thioetherification under visible light irradiation, yielding a diverse array of aryl alkyl thioethers, including d3-methyl aryl thioethers. A key discovery is that tetramethylthiourea can serve as both a sulfur source and an electron donor, facilitating the formation of the EDA complex with arylsulfonium salts. The method's effectiveness in gram-scale synthesis and adaptability for continuous flow processes underscore its significant synthetic potential and versatility.
{"title":"A catalyst- and thiol-free protocol for arene C–H thioetherification via photoactive electron donor–acceptor complexes†","authors":"Ang Gao, He-Xiang Liu, Ya-Nan Zhou and Ming-Chen Fu","doi":"10.1039/D4GC06257D","DOIUrl":"https://doi.org/10.1039/D4GC06257D","url":null,"abstract":"<p >We present a catalyst- and thiol-free protocol for arene C–H thioetherification under visible light irradiation, yielding a diverse array of aryl alkyl thioethers, including <em>d</em><small><sub>3</sub></small>-methyl aryl thioethers. A key discovery is that tetramethylthiourea can serve as both a sulfur source and an electron donor, facilitating the formation of the EDA complex with arylsulfonium salts. The method's effectiveness in gram-scale synthesis and adaptability for continuous flow processes underscore its significant synthetic potential and versatility.</p>","PeriodicalId":78,"journal":{"name":"Green Chemistry","volume":" 8","pages":" 2286-2292"},"PeriodicalIF":9.3,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143430739","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}