Catalytic Methoxycarbonylation of 1,6-Hexamethylenediamine with Methyl Carbamate to Dimethylhexane-1,6-Dicarbamate

2013 ◽  
Vol 634-638 ◽  
pp. 490-493
Author(s):  
Bing Han ◽  
Wen Bo Zhao ◽  
Xian Ye Qin ◽  
Yan Hong Li ◽  
Wei Wei

A series of metal oxides were employed as catalysts for the synthesis of dimethylhexane -1,6-dicarbamate(HDC) from 1,6-hexamethylenediamine(HDA) and methyl carbonate(MC). Lead dioxide showed excellent catalytic activity, 100% HDA conversion and 93% HDC yield could be achieved at 463K for 6h. The effects of reaction temperature, reaction time and catalyst amount on the yield of HDC were investigated in details.

2013 ◽  
Vol 291-294 ◽  
pp. 249-252
Author(s):  
Ying Liu ◽  
Lu Lin ◽  
Xiao Yu Sui ◽  
Jun Ping Zhuang ◽  
Chun Sheng Pang

Hydrolysis of glucose to produce levulinic acid catalyzed by ZSM-5 loading SO42-/ ZrO2 was studied in this paper. The effects of different factors such as catalyst amount, reaction temperature, reaction time on the yields of levulinic acid and hydroxymethyl furfural were investigated. It was found that the highest yield of levulinic acid was 55.03% (molar percent) under the conditions of catalyst amount 3 g, reaction temperature 180 °C and reaction time 2.5 h. Surface structure of catalyst was analyzed by FT-IR, indicating that crystallinity of catalyst was 0.66.


2011 ◽  
Vol 233-235 ◽  
pp. 188-193 ◽  
Author(s):  
Hai Bing Yu ◽  
Jun Nan ◽  
Jing Cheng Zhang ◽  
Jian Zhou Gui

Alkylation of phenol with cyclohexanol catalyzed by acidic ionic liquid has been investigated. The influences of reaction temperature, reaction time, reactant ratio (mol ratio of phenol to cyclohexanol), the amount and the recycle of ionic liquid on catalytic activity were studied. The conversion of phenol and the selectivity of paracyclohexylphenol were 75.5% and 61.6%, respectively, under optimum reaction conditions. The ionic liquid was utilized repeatedly over three times without remarkable loss of catalytic activity.


2011 ◽  
Vol 183-185 ◽  
pp. 1568-1572
Author(s):  
Yan Xiu Liu ◽  
Hua Song

Oxidation extraction of thiophene from simulated oil by using K2FeO4as oxidant and methanol as extractant has been investigated. The effects of different catalyst, oxidant amount, catalyst amount, reaction temperature, reaction time, and extraction conditions were studied. This process is capable of decreasing the sulfur content of simulated oil from 100 mg•L-1to 17.8 mg•L-1at the optimal conditions. The results indicate that such a process could be an alternative to common hydrodesulfurization for deep desulfurization.


Catalysts ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 1078
Author(s):  
Hang Zhang ◽  
Zhipeng Ma ◽  
Yunpeng Min ◽  
Huiru Wang ◽  
Ru Zhang ◽  
...  

Several kinds of composite materials with phosphotungstic acid (PTA) as the catalyst were prepared with activated carbon as support, and their structures were characterized. According to the Box–Behnken central combination principle, the mathematical model of the heterogeneous system is established. Based on the single-factor experiments, the reaction temperature, the reaction time, the amount of hydrogen peroxide and the loading capacity of PTA were selected as the influencing factors to study the catalyzed oxidation of hydrogen peroxide and degradation of high molecular weight chitosan. The results of IR showed that the catalyst had a Keggin structure. The results of the mercury intrusion test showed that the pore structure of the supported PTA catalyst did not change significantly, and with the increase of PTA loading, the porosity and pore volume decreased regularly, which indicated that PTA molecules had been absorbed and filled into the pore of activated carbon. The results of Response Surface Design (RSD) showed that the optimum reaction conditions of supported PTA catalysts for oxidative degradation of high molecular weight chitosan by hydrogen peroxide were as follows: reaction temperature was 70 ℃, reaction time was 3.0 h, the ratio of hydrogen peroxide to chitosan was 2.4 and the catalyst loading was 30%. Under these conditions, the yield and molecular weight of water-soluble chitosan were 62.8% and 1290 Da, respectively. The supported PTA catalyst maintained high catalytic activity after three reuses, which indicated that the supported PTA catalyst had excellent catalytic activity and stable performance compared with the PTA catalyst.


2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Xiaofang Liu ◽  
Zhigang Liu ◽  
Qiuyun Zhang ◽  
Hongguo Wu ◽  
Rui Wang

MIL-101(Fe) was explored for the first time for the catalytic conversion of glucose into lactic acid (LA). The as-synthesized MIL-101(Fe) was successfully characterized, and its higher specific surface area, porosity, and feasible acid properties were confirmed to determine the remarkable catalytic activity in glucose-to-LA conversion (up to 25.4% yield) compared with other catalysts like MIL-101(Cr, Al) and UiO-66(Zr). The reaction parameters including temperature, reaction time, and substrate species as well as catalyst reusability were discussed.


2011 ◽  
Vol 239-242 ◽  
pp. 1118-1122 ◽  
Author(s):  
Ping Ke Yan ◽  
Bin Wang ◽  
Yu Juan Gao

In this paper, nesquehonite whiskers were synthesized by low-temperature aqueous solution method, and the impacts of reaction temperature, reaction time and surfactant dosage and other factors on the maximum whisker length and high aspect ratios of nesquehonite whiskers were also investigated. Results showed that under the conditions that the reaction temperature was 40 – 50 °C the reaction time was 50 – 60min and the amount of surfactant dosage was 1% (by mass), high aspect ratios nesquehonite whisker products can be synthesized. On this basis, growth mechanism of the nesquehonite whiskers was discussed.


2019 ◽  
Vol 43 (9-10) ◽  
pp. 419-425 ◽  
Author(s):  
Huanhuan Dong ◽  
Shichao Xu ◽  
Jing Wang ◽  
Yuxiang Chen ◽  
Liangwu Bi ◽  
...  

Selective aerobic oxidation of α-pinene to high-value products is a major challenge in chemistry. Metalloporphyrins are proved to be selective catalysts for aerobic oxidation of simple hydrocarbons. Herein, we extend this method to more complex substrates using metallodeuteroporphyrins as model catalysts. It was found that the oxidation occurs mainly on the C=C and allylic C–H bonds of α-pinene influenced by the reaction temperature, reaction time, catalyst concentration, and oxygen flow rate. Allylic C–H oxidation products are obtained with a maximum selectivity value of 78.4% using the following reaction conditions: 105°C, 7 h, 5 ppm, and 60 mL/min. The influence of the metal nuclei of the metallodeuteroporphyrins on this reaction is also investigated. It was found that metallodeuteroporphyrins with Fe3+ as the metal nucleus exhibit the highest catalytic activity.


2011 ◽  
Vol 183-185 ◽  
pp. 1110-1113
Author(s):  
Yuan Bo Huang ◽  
Yun Wu Zheng ◽  
Hao Feng ◽  
Zhi Feng Zheng ◽  
Ying Zi Jiang

The liquefaction of corncob in polyhydric alcohols was investigated by using sulfuric acid as a catalyst. Results showed that the best liquefaction could be obtained with residue percent of 4.5% under the conditions with the corncob/polyhydric alcohols mass ratio of 1/5, reaction temperature of 150°C, reaction time of 60 min, catalyst amount of 3% (based on the weight of corncob), PEG 400/glycerin mass ratio of 7/3 in the polyhydric alcohols, respectively. The liquefied liquid products had acid number of 18.9 mg KOH/g and hydroxyl number of 616.3mg KOH/g, respectively.


2013 ◽  
Vol 821-822 ◽  
pp. 1081-1084 ◽  
Author(s):  
Xian Ye Qin ◽  
Biao Liu ◽  
Bing Han ◽  
Wen Bo Zhao ◽  
Shui Sheng Wu ◽  
...  

The catalytic activity of many Lewis and Bronsted acid for the synthesis of diethyl carbonate (DEC) from ethyl carbamate (EC) and ethanol was evaluated in a bath reactor. Pyrophosphoric acid (H4P7O2) which showed the best activity was selected to further investigate the effect of reaction conditions, such as reaction temperature, catalyst dose and reaction time, on the yield of DEC. Under the optimal conditions, DEC yield can reach 29.1%.


2013 ◽  
Vol 781-784 ◽  
pp. 2433-2437 ◽  
Author(s):  
Ai Hua Zhang ◽  
Zhi Hong Xiao ◽  
Liang Bo Zhang ◽  
Ru Kuan Liu ◽  
Wu Hong Zhong ◽  
...  

Research on the synthesis of BrOnsted acidic ionic liquid by the method of solvent, the pyrolysis bio-fuel with cornus wisoniana oil drop acid esterification reaction, the catalyst dosage, reaction time and reaction temperature on the effects of the acid dropping and in the best optimization under the condition of the stability of the catalyst were investigated. The experimental results show that [BSPHSO4 with high catalytic activity, optimization of process conditions as follows: 1.2% of catalyst, reaction temperature 75 °C, reaction time of 70 min, acid value reduced to 2.0 mg KOH/g. By optimizing the cycle experiment, the stability of the catalyst performance is good, the catalytic activity is relatively stable.


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