Catalysts
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2021
·Vol. 11
·期 10
·1187
·
IF 4.146
Qiuyue Zhou,Zhi-Qiang Wang,Wei Hong,Baohui Lou,Shihui Zou
Oxidative dehydrogenation of KA-oil (a mixture of cyclohexanone and cyclohexanol) is an economically attractive process to produce cyclohexanone because it provides a chance to avoid the energy-intensive alcohol-ketone separation process. The application of this process, however, is hampered by the low cyclohexanone selectivity which results from the competitive adsorption of cyclohexanol and cyclohexanone on the catalyst surface. Herein, by engineering Pt-Bi2O3interface to tune the geometric and electronic structure of Pt, we successfully weaken the cyclohexanone adsorption without compromising the oxidation of cyclohexanol. As a result, Bi2O3-Pt/SiO2with Bi-to-Pd ratio of 0.2 exhibits a 5 times higher cyclohexanone selectivity than Pt/SiO2at the same conversion of KA oil. Long term test suggests that the Pt-Bi2O3interface is stable in the oxidative dehydrogenation of KA-oil.Keywords:KA-oil;oxidative dehydrogenation;bismuth;Pt;electronic effect
研究领域:
化学工程
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催化科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Sustainable Chemistry & Engineering
·
2024
·
IF 7.1
Jie Chen,Yi Shen
Selective oxidative cleavage of C(OH)–C or C(O)–C bonds in cyclohexanol and cyclohexanone (KA oil) to produce adipic acid (AA), a monomer for the synthesis of nylon-66, is of significant importance for the petrochemical industry. Herein, we report an electrochemical method to improve the efficiency for upgrading KA oil into AA. Free-standing electrodes consisting of hydroxides (Ni(OH)2 and Mn-doped Ni(OH)2) supported by carbon paper were fabricated via an in situ electrodeposition process and further examined for KA oil conversion. The morphology and structures of the samples were characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, and Raman spectroscopy. The electrochemical performance of the samples was studied by cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy. The products of KA oil oxidation were analyzed by high-performance liquid chromatography. The introduction of manganese into nickel hydroxides enhanced the catalytic performance in terms of activity and product selectivity. Specifically, the optimal sample exhibited a current density of 50 mA mg–1 and selectivity of 46.8%, which are superior to those of pure nickel hydroxides. Such enhancement was attributed to the electronic interaction of manganese with nickel hydroxides, thereby modifying the adsorption of the substrates. Interestingly, the introduction of Mn into nickel hydroxides had negligible effects in the oxygen evolution reaction. The effects of critical parameters including substrate composition, reaction temperatures, KOH concentrations, and electrolysis time on the conversion of KA oil were investigated.
研究领域:
材料科学
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电化学
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催化反应
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产品关联
DOI
高影响因子
ACS Catalysis
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2013
·
IF 5.265
Wen-Juan Zhou,Raphael Wischert,Kai Xue,Yu-Ting Zheng,Belén Albela,Laurent Bonneviot,Jean-Marc Clacens,Floryan De Campo,Marc Pera-Titus,Peng Wu
Various types of Ti-containing zeolites, i.e., Ti-MWW, TS-1, Ti-MOR, and Ti-BEA, have been evaluated as candidates for the liquid-phase oxidation of cyclohexane using t-butyl hydroperoxide (TBHP, 7–8 wt %) as model oxidant. Ti-MWW zeolite displayed the highest activity for cyclohexanol and cyclohexanone (KA oil) with an overall selectivity higher than 90% at 80 °C, making this catalyst a candidate of choice for industrial KA oil production by deperoxidation of cyclohexyl hydroperoxide. The effect of the reaction temperature, reaction time, catalyst amount, and catalyst stability on Ti-MWW was surveyed in detail. The Ti-MWW catalyst showed a stable performance and could be recycled at least four times without detectable Ti leaching and loss of structural stability. The active sites for cyclohexane oxidation appeared to be located near external 12-ring cups in the Ti-MWW framework as suggested by a series of position-selective poisoning tests with tripropyl- and triphenylamine, impelling cyclohexane diffusion within the internal 10-ring channels. EPR experiments supported by DFT calculations suggested the coexistence of both Ti(IV)-OO• (peroxyl) and Ti(IV)-O• (oxyl) species generated through bimolecular pathways, implying simultaneously (SiO)3Ti(OOtBu) species and tBuOOH. The catalytic activity was strongly inhibited in the presence of alkenes, leading to the preferential formation of the epoxidation product with no detectable formation of radicals. Notably, this is the first time that oxyl species have been detected particularly with the help of DFT calculations. Predicted differences of g tensors between peroxyl and oxyl species at various hydration levels in the presence of cyclohexane were consistent with the EPR spectra.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MOLECULAR CATALYSIS A-CHEMICAL
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2014
·
IF 3.679
Yujia Xie,Fengyong Zhang,Pingle Liu,Fang Hao,He’an Luo
Metalloporphyrin-catalysed direct functionalization of saturated C H bonds is one among the topical and challenging areas within the chemical industry. In this work, three types of unsupported and boehmite supported trans-A 2 B 2 -metalloporphyrin chloride complexes (Co-D( p -Cl)PPCl, Fe-D( p -Cl)PPCl, Mn-D( p -Cl)PPCl) were prepared and characterized. It has been found that these trans-A 2 B 2 -metalloporphyrins have high catalytic activity in cyclohexane oxidation under dioxygen. The boehmite supported metalloporphyrins show better catalytic performance and are more stable than unsupported metalloporphyrins. Among these supported metalloporphyrin catalysts, Co-D( p -Cl)PPCl/BM was better than Fe-D( p -Cl)PPCl/BM and Mn-D( p -Cl)PPCl/BM, the cyclohexane conversion and selectivity to KA oil are 6.83% and 83.30%, respectively, and the turnover number is 1.05 × 10 7 . The Co-D( p -Cl)PPCl/BM catalyst can be facilely recovered and was recycled up to six times without significant decrease in catalytic performance.
研究领域:
化学工业
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催化化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2022
·
IF 7.392
Junlei Wang,Kuan Wang,Zhen-Hong He,Rong-Rong Zhang,Pengfei Guo,Weitao Wang,Yang Yang,Zhao-Tie Liu
Photocatalytic oxidation of cyclohexane (CHA) with air in solvent-free is an efficient and green approach for the production of cyclohexanol and cyclohexanone (KA oil). In the present work, ultrathin Bi 2 WO 6 /BiOCl heterojunction nanosheets are prepared by varying the amounts of potassium chloride (KCl) via a one-step solvothermal method. The oxygen vacancies (OV) in Bi 2 WO 6 /BiOCl nanosheets can be produced in situ during the photocatalysis. An efficient and selective photo-oxidation of CHA to KA oil with air as an oxidant in solvent-free was achieved over OV-Bi 2 WO 6 /BiOCl catalyst. The composition, structure, morphology, as well as textural, optical, and electrochemical properties of the photocatalysts are systematically analyzed by various characterization techniques. The photocatalytic activity (KA oil, 484.4 μmol) for the titled reaction was significantly improved over OV-Bi 2 WO 6 /BiOCl with 1.8 and 9.8 times compared with that by pure BiOCl and Bi 2 WO 6 catalysts, respectively. Meanwhile, up to 92.5% selectivity of KA oil and 5 cycles without photocatalytic activity loss were achieved. The photogenerated holes (h + ) and ·OH radicals are verified to be predominant reactive species by trapping experiments and electron paramagnetic resonance (EPR) tests. The excellent photocatalytic performance can be attributed to the enhanced photo-absorption, abundant oxygen vacancies, high exposure of active facets, and efficient electron-hole separation. Thereby, the present work offers a prospective strategy for constructing Bi-based photocatalyst with highly efficient and selective photocatalytic oxidation of CHA.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CATALYSIS
·
2025
·
IF 6.5
Jue Wang,Jinyi Yang,Siyu Zeng,Huitao Liu,Fei Li,Haijiao Xie,Senpei Tang,Zaihui Fu,Youji Li
The highly selective synthesis of KA oil (cyclohexanol and cyclohexanone) from the oxidation of cyclohexane (CHA) with O 2 under mild conditions is still a very important and challenging research topic. This paper discloses that the hybrid (DTCN) is easily prepared by inducing carbon nitride (CN) in the synthesis of decatungstate (DT) and is found to be efficiently photo-catalyst for the above selective oxidation in acetonitrile. After illumination (LED of 405 nm) for 2 h, the best DTCN-0.5 can achieve 41.03 % CHA conversion and greater than 95 % KA oil selectivity with an apparent quantum efficiency of 25.52 %, which is much superior to the pure DT (12.46 % CHA conversion). Also, it is active for the selective oxidation of other substrates containing inert C(sp 3 )-H bonds. A series of characterizations, free radical trapping and isotope tracing tests as well as DFT calculations support that the doped CN can construct a built-in electric field with DT to accelerate the separation of the photo-generated charge, thus hoisting the photo-excited quantum efficiency of DT. Furthermore, it also plays a key role in converting O 2 into superoxide (•O 2 – ) radical as the active oxygen donor. Additionally, the doped CN also contributes to the limited participation of water as a weak oxygen donor in the selective oxidation of CHA to cyclohexanol. It is hoped that this work will be informative for advancing the key technology of selective oxidation of saturated hydrocarbons under mild conditions.
研究领域:
化学工程
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材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
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2024
·
IF 8.3
Shuang Wei,Kexin Li,Sheng Zhong,Ruirui Zhang,Guosheng Wang,Ruixia Liu
Selective conversion of inert C–H bonds in alkanes into high-value-added functional groups (alcohols, ketones, carboxylic acids, etc.) plays a vital role in establishing a green and sustainable chemical industry. Catalytic selective oxidation of cyclohexane to KA oil (cyclohexanol and cyclohexanone) is a typical representative of alkane functionalization. In this work, hollow cage-like Co3O4 (Co3O4-C) and particle Co3O4 (Co3O4-P) were synthesized by calcining two types of Prussian blue analogues (PBAs), which were used to catalyze the selective oxidation of cyclohexane. The Co3O4-C predominantly exposed (311) crystal plane is easier to adsorb cyclohexane than Co3O4-P, which is beneficial to shorten the induction period, accelerate the reaction rate, and improve the conversion. Consequently, Co3O4-C displayed a 10% conversion of cyclohexane within 1 h, and the KA oil selectivity reached 90%. The Co3O4-P exposed (220) crystal plane has a higher molar percentage of oxygen vacancies and more active oxygen species, as well as a strong cyclohexanone adsorption capacity, which is conducive to the deep oxidation of cyclohexanone to adipic acid and other diacid products. The mechanism analysis of cyclohexane oxidation catalyzed by PBA-based Co3O4 shows that it exemplifies the feasibility to tailor the surface of catalysts by modulating the PBAs, which ultimately influences their reaction performance for accelerating the reaction and maintaining high cyclohexane conversion and KA oil selectivity.
研究领域:
催化化学
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绿色化学
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材料科学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED SURFACE SCIENCE
·
2024
·
IF 6.3
Kuan Wang,Yi Wang,Dan Wang,Yuan-Xiao Du,Xin-Peng Li,Zhen-Hong He,Huan Wang,Weitao Wang,Yang Yang,Zhao-Tie Liu
The exploration of cost-efficient, environmentally friendly, and high-efficacy photocatalysts for the enhanced selective photooxidation of cyclohexane to KA oil (cyclohexanone (CHA-one) and cyclohexanol (CHA-ol)) is a pivotal challenge in the industrial realm. Herein, the present study focuses on the synthesis of needle-like S-scheme heterojunction photocatalysts with oxygen vacancies, which are achieved by the needle growth integration of nano-sized Nb 2 O 5 particles onto the BiOCl nanosheets. Remarkably, the 40 % Nb 2 O 5 /BiOCl composites exhibited superior performance in the solvent-free photooxidation of cyclohexane at room-temperature and under atmospheric pressure. The production yield of KA oil was 180.3 μmol (CHA-one/CHA-ol molar ratio = 3.5), and exceptional selectivity towards KA oil, reaching up to 99.3 %. The enhanced photocatalytic efficiency in cyclohexane oxidation can be attributed to the unique S-scheme heterogeneous interfaces with specific nanoneedle morphology, which result in the enhanced photonic absorption, effective charge carrier separation, a high density of oxygen vacancies, and the exposure of the highly reactive (001) plane of BiOCl. The excellent interfacial charge separation and transfer pathways of S-scheme heterojunction are disclosed by the in-depth EPR analysis and DFT calculations. These insights highlight the significant potential of the needle-like Bi-based S-scheme heterojunction photocatalysts for the efficient photooxidation of saturated alkanes.
研究领域:
材料科学
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催化化学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2015
·Vol. 5
·期 123
·101593-101598
·
IF 3.84
Ze Feng,Yujia Xie,Fang Hao,Pingle Liu,He'an Luo
A series of meso-substituted metal tetraphenylporphyrins were synthesized and characterized by UV-vis, FT-IR and elemental analysis. The experimental results show that cobalt tetra(4-nitrophonyl)porphyrin (Co–TNPP) gives better catalytic performance in cyclohexane oxidation. The KA oil (cyclohexanol and cyclohexanone) selectivity is 79.54% at the cyclohexane conversion of 10.43%, and the turnover number reaches to 0.93 × 104. Cyclohexane oxidation catalyzed by meso-substituted metalloporphyrins was studied by molecular simulation and experiment. The results of molecular simulation performed by Materials Studio show that the substituted electron-withdrawing groups in the same central metal porphyrins reduce the HOMO and LUMO energies. The metalloporphyrins with lower energy gap have stronger ability to activate the oxygen, the metalloporphyrin intermediates with lower energy gap have stronger ability to activate the cyclohexane.
研究领域:
化学
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材料科学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Shengxin Chen,Bin He,Yingwei Li,Ruirui Wang,Ping Chen,Xingang Li,Ruixia Liu
The selective oxidation of cyclohexane to cyclohexanone and cyclohexanol (KA oils) without additional initiator remains a challenge because of its inherent low activity and limited selectivity. To promote the selectivity of KA oils at high reaction conversion, a series of novel cobalt-based poly(ionic liquid)s (Co-PILs) catalysts were designed. The electronic structure and the microenvironment of Co sites in Co-PILs were regulated by tuning the contents of Co. By the regulation of the microenvironment, the cyclohexane conversion and KA oils selectivity are improved by 19% and 47% (Co-PIL-1–2.5) compared with traditional metal salt catalysts, respectively. Mechanistic studies demonstrated that the electronic structure and coordination environment of transition metals can be effectively tailored. Notably, Co-PILs with low metal loading exhibit a remarkable ability to improve the reaction by transitioning from a low-spin to a high-spin state. Moreover, by adjusting the ratio of cobalt ions to ionic liquid monomers derived from PILs, the acidity, oxygen activation, and desorption of reactive oxygen species were also regulated accordingly. These properties play a pivotal role in the oxidation process, ultimately allowing for precise control over the activity and selectivity.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POROUS MATERIALS
·
2021
·Vol. 29
·期 2
·371-380
·
IF 2.496
Zhang Wei,Xue Haonan,Wang Min,Wu Zeying,Ding Linlin,Deng Yaoyao,Wang Wei,Wei Xuejiao,Zhang Zhenwei,Xiang Mei
Cu-containing Beta zeolites (Cu-Beta) are straightforwardly synthesized in a one-pot method without template, where the crucial step is the co-hydrolysis/condensation of silica source and copper salt at the moderate acidic condition. In the solvent-free oxidation of cyclohexane with molecular oxygen (O 2 ), the best cyclohexane conversion result (9.7%) with a KA-oil (cyclohexanone and cyclohexanol) selectivity of 94.1% is obtained over Cu-Beta(100). Structure—activity relationship analysis indicates that the isolated tetrahedral framework Cu 2+ species and chemisorption oxygen species in high concentration on the catalyst surface enhannce the catalic performance. In addition, the catalyst can be easily separated and still remain stable after recycling five times, providing new insights into catalysts design for the catalytic oxidation of cyclohexane to KA-oil.
研究领域:
催化化学
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材料科学
✓ 已验证
产品关联
DOI
高影响因子
Green Chemical Engineering
·
2023
·
IF 0
Ying Jin,Shengxin Chen,Ruirui Wang,Yumei Liu,Xinxin Li,Yingwei Li,Ruirui Zhang,Ruixia Liu
Poly(ionic liquids) (PILs) combined with the macromolecular structure and unique properties of ionic liquids show unlimited potential in catalysis. In this work, a series of metal-based PIL with different ionic ratios were prepared for the selective oxidation of cyclohexane. Characterization analysis reveals that different degrees of ionization could adjust the Co–N sites of the catalysts efficiently, leading to significant changes in their electronic structure, which strongly relate to catalytic performance in oxidation. 20.07% cyclohexane conversion and 13.06% cyclohexanone and cyclohexanol (KA oil) yield can be achieved by metal-based PILs that are better than other commercial catalysts. Compared with CoCl 2 , metal-based PILs perform well, with superior conversion and KA oil yield. More interestingly, the catalyst created in this study features a malleable Co–N site, which may potentially have an impact on how oxygen species adsorb and desorb from the catalyst. Therefore, the catalyst studied in this work is used as molecular oxygen for the selective oxidation of cyclohexane to produce KA oil, and its application prospect is promising.
研究领域:
催化化学
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材料科学
✓ 已验证
DOI
危险品化学品经营许可证（带存储）