Solvent-free liquid-phase selective catalytic oxidation of toluene to benzyl alcohol and benzaldehyde over CeO2-MnOx composite oxides

Author(s):  
Gui Chen ◽  
Kuiyi You ◽  
Xiangbo Gong ◽  
Fangfang Zhao ◽  
Zhenpan Chen ◽  
...  

An efficient method for highly selective preparation of the high value-added benzyl alcohol (BOL) and benzaldehyde (BAL) from liquid-phase catalytic oxidation of toluene with molecular oxygen over CeO2-MnOx composite oxides...

Molecules ◽  
2019 ◽  
Vol 24 (7) ◽  
pp. 1281 ◽  
Author(s):  
Yongwei Ju ◽  
Zhongtian Du ◽  
Chuhong Xiao ◽  
Xingfei Li ◽  
Shuang Li

Selective oxidation of α-hydroxy esters is one of the most important methods to prepare high value-added α-keto esters. An efficient catalytic system consisting of Zn(NO3)2/VOC2O4 is reported for catalytic oxidation of α-hydroxy esters with molecular oxygen. Up to 99% conversion of methyl DL-mandelate or methyl lactate could be facilely obtained with high selectivity for its corresponding α-keto ester under mild reaction conditions. Zn(NO3)2 exhibited higher catalytic activity in combination with VOC2O4 compared with Fe(NO3)3 and different nitric oxidative gases were detected by situ attenuated total reflection infrared (ATR-IR) spectroscopy. UV-vis and ATR-IR results indicated that coordination complex formed in Zn(NO3)2 in CH3CN solution was quite different from Fe(NO3)3; it is proposed that the charge-transfer from Zn2+ to coordinated nitrate groups might account for the generation of different nitric oxidative gases. The XPS result indicate that nitric oxidative gas derived from the interaction of Zn(NO3)2 with VOC2O4 could be in favor of oxidizing VOC2O4 to generate active vanadium (V) species. It might account for different catalytic activity of Zn(NO3)2 or Fe(NO3)3 combined with VOC2O4. This work contributes to further development of efficient aerobic oxidation under mild reaction conditions.


2008 ◽  
Vol 86 (3) ◽  
pp. 199-204 ◽  
Author(s):  
Guan Huang ◽  
Chun-Cai Cai ◽  
Jin Luo ◽  
Hong Zhou ◽  
Yong-An Guo ◽  
...  

The highly selective catalytic oxidation of toluene with air to benzaldehyde and benzyl alcohol in the liquid phase has been studied with the use of iron tetraphenylporphyrin (Fe TPP) supported on chitosan (CTS), (Fe TPP/CTS). The rates of toluene conversion and selectivity (aldehyde + alcohol) were subject to the reaction temperature, air pressure, and amount of iron tetraphenylporphyrin. By the use of the Fe TPP/CTS, containing 2 mg of iron tetraphenylporphyrin as catalyst, toluene oxidation with air under the optimum conditions of 190 °C and 0.6 MPa produced benzaldehyde and benzyl alcohol at 90% selectivity and 5.4% conversion of toluene, the mole turnover of the catalyst was about 6 × 106, and it could be reused efficiently for one more time. It is suggested that the amine groups (–NH2) on the chitosan chain act as a key assistor to the catalysis of Fe TPP for toluene oxidation. Compared with the conventional method of synthesizing benzaldehyde and benzyl alcohol, the new method has the advantages of reduced environmental pollution, higher selectivity for the two main products, and easy recovery of the catalyst.Key words: chitosan-supported iron porphyrin, catalysis, toluene oxidation, benzaldehyde, benzyl alcohol.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 34
Author(s):  
Devendra P. Tekale ◽  
Ganapati D. Yadav ◽  
Ajay K. Dalai

Value addition to glycerol, the sole co-product in biodiesel production, will lead to reform of the overall biodiesel economy. Different valuable chemicals can be produced from glycerol using heterogeneous catalysis and these valuable chemicals are useful in industries such as cosmetics, pharmaceuticals, fuels, soap, paints, and fine chemicals. Therefore, the conversion of glycerol to valuable chemicals using heterogeneous catalysis is a noteworthy area of research. Etherification of glycerol with alkenes or alcohols is an important reaction in converting glycerol to various value-added chemicals. This article describes reaction of glycerol with benzyl alcohol in solvent-free medium by using a clay supported modified heteropolyacid (HPA), Cs2.5H0.5PW12O40/K-10 (Cs-DTP/K-10) as solid catalyst and its comparison with other catalysts in a batch reactor. Mono-Benzyl glycerol ether (MBGE) was the major product formed in the reaction along with formation of di-benzyl glycerol ether (DBGE). The effects of different parameters were studied to optimize the reaction parameters. This work provides an insight into characterization of Cs2.5H0.5PW12O40/K-10 catalyst by advanced techniques such as surface area measurement, X-ray analysis, ICP-MS, FT-IR, and SEM. Reaction products were characterized and confirmed by using the GCMS method. The kinetic model was developed from an insight into the reaction mechanism. The apparent energy of activation was found to be 18.84 kcal/mol.


2020 ◽  
Vol 8 ◽  
Author(s):  
Shurui Xu ◽  
Jie Wu ◽  
Peng Huang ◽  
Chunwen Lao ◽  
Hanchao Lai ◽  
...  

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