Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic fram...Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.展开更多
The liquid phase oxidation of cyclohexylbenzene(CHB)is a new green synthetic approach to cyclohexylbenzene-1-hydroperoxide(CHBHP),a key intermediate for preparing phenol and cyclohexanone.In this work,aryl-substituted...The liquid phase oxidation of cyclohexylbenzene(CHB)is a new green synthetic approach to cyclohexylbenzene-1-hydroperoxide(CHBHP),a key intermediate for preparing phenol and cyclohexanone.In this work,aryl-substituted(Cl and Br)derivatives of N-hydroxyphthalimide(NHPI)were synthesized and their catalytic performances for CHB oxidation were studied.In addition,geometric optimization and transition state search were performed using DFT calculations.Both experimental and theoretical studies have proven that chloro-substitution on NHPI can significantly improve its catalytic effects on the oxidation of CHB by oxygen.Compared with NHPI,CHB conversion and selectivity of CHBHP over Cl;NHPI were increased by 10.47%and 13.24%.The strategy of aryl-substituting NHPI with halogen atoms proposed in this study would provide a potential way to the development of new NHPI-based catalysts for aerobic oxidation reactions.展开更多
The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-...The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA.展开更多
A metal-free N-hydroxyphthalimide/hexagonal boron nitride(NHPI/h-BN)catalytic system was developed for deep oxidative desulfurization(ODS)of fuel oils.Detailed experiments find that the heterogenization process of loa...A metal-free N-hydroxyphthalimide/hexagonal boron nitride(NHPI/h-BN)catalytic system was developed for deep oxidative desulfurization(ODS)of fuel oils.Detailed experiments find that the heterogenization process of loading NHPI on h-BN not only benefits to the dispersion and utilization of NHPI,but also can significantly promote the catalytic performance.By employing NHPI/h-BN as the catalyst,azodiisobutyronitrile(AIBN)as the metal-free initiator,a 95%conversion of dibenzothiophene(DBT)can be acquired under the reaction conditions of 120°C and atmospheric pressure with molecular oxygen(O_(2))as oxidant.Moreover,the heterogenization is convenient for the regeneration of the catalyst with>94%DBT conversion after being recycled seven times.Characterizations illustrate that the promoted catalytic activity along with the regenerability originate from the interactions between NHPI and h-BN.The catalytic mechanism study shows that molecular oxygen is readily activated by the NHPI/h-BN to form a superoxide radical(O_(2)^(·-)),which oxidize DBT to DBTO2 for desulfurization.展开更多
A practical catalytic method to oxidize α-ionone with molecular oxygen using N-hydroxyphthalimide(NHPI)combined with acetylacetone cobatt(Ⅱ)(Co(acac)2)was developed,and the probable catalytic mechanism was proposed....A practical catalytic method to oxidize α-ionone with molecular oxygen using N-hydroxyphthalimide(NHPI)combined with acetylacetone cobatt(Ⅱ)(Co(acac)2)was developed,and the probable catalytic mechanism was proposed.The influences of the reaction conditions on conversion of α-ionone and the selectivity of the major product(5-keto-α-ionone)were investigated,and the technical parameters for 5-keto-α-ionone were optimized.The results show that the primary product is 5-keto-α-ionone,and by-products include epoxy-α-ionone,as well as rearrangement products 4-keto-β-ionone and epoxy-β-ionone,which are characterized by infrared spectra,proton nuclear magnetic resonance spectra,mass spectra and elemental analysis.The selectivity of 5-keto-α-ionone and the conversion of α-ionone are 55.0% and 97.0%,respectively,when 30%(molar fraction)NHPI,1.0%(molar fraction)Co(acac)2 and no solvent are employed under O2 pressure of 1.0 MPa and the reaction temperature of 65℃for 11 h.The procedure shows good reproducibility in the parallel experiments.展开更多
Efficient catalytic oxidation of ethylbenzene to acetophenone was realized using the catalytic system of cobalt zeolitic imidazolate framework ZIF-67/N-hydroxyphthalimide （NHPI） under mild conditions. 95.2% conversi...Efficient catalytic oxidation of ethylbenzene to acetophenone was realized using the catalytic system of cobalt zeolitic imidazolate framework ZIF-67/N-hydroxyphthalimide （NHPI） under mild conditions. 95.2% conversion of ethylbenzene with 90.3% selectivity to acetophenone could be obtained at 373 K under 0.3 MPa 02 for 9 h. The results show that there exists synergetic effect between ZIF-67 and NHPI. 1-Phenylethyl hydroperoxide （PEHP） was generated via a radical process involving the hydrogen abstraction from ethylbenzene by phthalimide N-oxyl, and subsequently effectively decomposed to acetophenone by ZIF-67.展开更多
基金This work was financially supported by the National Natural Science Foundation of China(Nos.21978119,22202088)Key Research and Development Plan of Hainan Province(ZDYF2022SHFZ285)Jiangsu Funding Program for Excellent Postdoctoral Talent(2022ZB636)。
文摘Synergic catalytic effect between active sites and supports greatly determines the catalytic activity for the aerobic oxidative desulfurization of fuel oils.In this work,Ni-doped Co-based bimetallic metal-organic framework(CoNi-MOF)is fabricated to disperse N-hydroxyphthalimide(NHPI),in which the whole catalyst provides plentiful synergic catalytic effect to improve the performance of oxidative desulfurization(ODS).As a bimetallic MOF,the second metal Ni doping results in the flower-like morphology and the modification of electronic properties,which ensure the exposure of NHPI and strengthen the synergistic effect of the overall catalyst.Compared with the monometallic Co-MOF and naked NHPI,the NHPI@CoNi-MOF triggers the efficient activation of molecular oxygen and improves the ODS performance without an initiator.The sulfur removal of dibenzothiophene-based model oil reaches 96.4%over the NHPI@CoNi-MOF catalyst in 8 h of reaction.Furthermore,the catalytic product of this aerobic ODS reaction is sulfone,which is adsorbed on the catalyst surface due to the difference in polarity.This work provides new insight and strategy for the design of a strong synergic catalytic effect between NHPI and bimetallic supports toward high-activity aerobic ODS materials.
基金financially supported by the National Natural Science Foundation of China(21706240)。
文摘The liquid phase oxidation of cyclohexylbenzene(CHB)is a new green synthetic approach to cyclohexylbenzene-1-hydroperoxide(CHBHP),a key intermediate for preparing phenol and cyclohexanone.In this work,aryl-substituted(Cl and Br)derivatives of N-hydroxyphthalimide(NHPI)were synthesized and their catalytic performances for CHB oxidation were studied.In addition,geometric optimization and transition state search were performed using DFT calculations.Both experimental and theoretical studies have proven that chloro-substitution on NHPI can significantly improve its catalytic effects on the oxidation of CHB by oxygen.Compared with NHPI,CHB conversion and selectivity of CHBHP over Cl;NHPI were increased by 10.47%and 13.24%.The strategy of aryl-substituting NHPI with halogen atoms proposed in this study would provide a potential way to the development of new NHPI-based catalysts for aerobic oxidation reactions.
基金supported by the National Natural Science Foundation of China(Grant No.20072025).
文摘The catalytic performance of a series of cobalt(Ⅱ) hydroxamates (CoL2) and the synergistic catalytic action of the cobalt complexes combined with N-hydroxyphthalimide (NHPI) in the aerobic oxidation of p-xylene to p-toluic acid (PTA) were investigated. The results showed that the existing synergistic action in the catalytic oxidation can shorten the induction period of the radical reaction and improve the yield of PTA.
基金the financial support from the National Key R&D Program of China(No.2017YFB0306504)National Natural Science Foundation of China(No.22008094,22178154 and 21878133)+2 种基金Chinese Postdoctoral Science Foundation(No.2019M651743,2020M671364 and 2020M673039)Natural Science Foundation of Jiangsu Province(No.BK20190852)Natural Science Foundation for Jiangsu Colleges and Universities(No.19KJB530005)
文摘A metal-free N-hydroxyphthalimide/hexagonal boron nitride(NHPI/h-BN)catalytic system was developed for deep oxidative desulfurization(ODS)of fuel oils.Detailed experiments find that the heterogenization process of loading NHPI on h-BN not only benefits to the dispersion and utilization of NHPI,but also can significantly promote the catalytic performance.By employing NHPI/h-BN as the catalyst,azodiisobutyronitrile(AIBN)as the metal-free initiator,a 95%conversion of dibenzothiophene(DBT)can be acquired under the reaction conditions of 120°C and atmospheric pressure with molecular oxygen(O_(2))as oxidant.Moreover,the heterogenization is convenient for the regeneration of the catalyst with>94%DBT conversion after being recycled seven times.Characterizations illustrate that the promoted catalytic activity along with the regenerability originate from the interactions between NHPI and h-BN.The catalytic mechanism study shows that molecular oxygen is readily activated by the NHPI/h-BN to form a superoxide radical(O_(2)^(·-)),which oxidize DBT to DBTO2 for desulfurization.
基金Project(50573019)supported by the National Natural Science Foundation of China
文摘A practical catalytic method to oxidize α-ionone with molecular oxygen using N-hydroxyphthalimide(NHPI)combined with acetylacetone cobatt(Ⅱ)(Co(acac)2)was developed,and the probable catalytic mechanism was proposed.The influences of the reaction conditions on conversion of α-ionone and the selectivity of the major product(5-keto-α-ionone)were investigated,and the technical parameters for 5-keto-α-ionone were optimized.The results show that the primary product is 5-keto-α-ionone,and by-products include epoxy-α-ionone,as well as rearrangement products 4-keto-β-ionone and epoxy-β-ionone,which are characterized by infrared spectra,proton nuclear magnetic resonance spectra,mass spectra and elemental analysis.The selectivity of 5-keto-α-ionone and the conversion of α-ionone are 55.0% and 97.0%,respectively,when 30%(molar fraction)NHPI,1.0%(molar fraction)Co(acac)2 and no solvent are employed under O2 pressure of 1.0 MPa and the reaction temperature of 65℃for 11 h.The procedure shows good reproducibility in the parallel experiments.
基金supported by the National Natural Science Foundation of China(21233008,21103175 and 20803074)the"Strategic Priority Research Program-Climate Change:Carbon Budget and Related Issues"of the Chinese Academy of Sciences(XDA05010203)
文摘Efficient catalytic oxidation of ethylbenzene to acetophenone was realized using the catalytic system of cobalt zeolitic imidazolate framework ZIF-67/N-hydroxyphthalimide （NHPI） under mild conditions. 95.2% conversion of ethylbenzene with 90.3% selectivity to acetophenone could be obtained at 373 K under 0.3 MPa 02 for 9 h. The results show that there exists synergetic effect between ZIF-67 and NHPI. 1-Phenylethyl hydroperoxide （PEHP） was generated via a radical process involving the hydrogen abstraction from ethylbenzene by phthalimide N-oxyl, and subsequently effectively decomposed to acetophenone by ZIF-67.
