793-24-8Relevant academic research and scientific papers
Effects of pore structure of MgO-templated mesoporous carbon on its supported Pt catalysts for reductive alkylation of p-aminodiphenylamine with methyl isobutyl ketone
Yu, Wenlong,Yu, Shitao,Ding, Junwei,Cheng, Qiuzhen,Liu, Fusheng
, p. 5109 - 5115 (2019)
Mesoporous carbon (MC) was prepared by the nano-MgO template method and used as a support for the preparation of a Pt-based reductive alkylation catalyst. N2 physical adsorption-desorption, scanning electron microscopy, transmission electron microscopy and X-ray diffraction were used to characterize the carbon supports and supported Pt catalysts. The effects of the pore structure of the Pt/MC catalyst on its performance for reductive alkylation of p-aminodiphenylamine with methyl isobutyl ketone were investigated. The results show that the surface area and pore structure of the MgO-templated mesoporous carbons can be modulated directionally by varying the size of nano-MgO particles and the MgO/PF mass ratio. The catalytic activity and stability of the catalysts for N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenediamine synthesis increases with an increase in the pore size of the mesoporous carbons. Complete conversion of p-ADPA and 100% selectivity to 6PPD were obtained over Pt/MC50(1/1) within 4 hours, which could maintain a high catalytic activity after being reused 10 times. The characterization results indicate that there was an obvious decrease in the BET specific surface area, pore volume and Pt specific surface area of all used catalysts compared with the fresh catalysts, and the trend was more obvious with the decrease of catalyst pore size, which should be the primary reason for the degradation of catalytic performance.
Synthesis method of antioxidant 6PPD to reduce side reactions
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Paragraph 0016; 0018-0019, (2022/03/02)
The present invention belongs to the field of fine chemical technology, relates to a method of continuous synthesis of adhesive antioxidant 6PPD. The patent of the present invention uses a precious metal catalyst to synthesize antioxidant 6PPD on a fixed bed, the precious metal catalyst is loaded into a fixed bed reaction device, nitrogen is filled with 0.1 ~ 0.5MPa pressure and replaces the entire high pressure reactor system, after the reaction system is replaced, the temperature rises, and the flow rate of hydrogen is 0.1 ~ 1L / min. Using 4-aminodiphenylamine and similar organic matter and methyl isobutyl methyl ketone and acetone as raw materials, the synthesis test of the antioxidant 6PPD using a precious metal catalyst was carried out. Compared with the existing precious metal kettle hydrogenation process, it has continuous operation, simple operation, avoids the catalyst loss caused by the use of powder catalyst due to filtration, and can reduce production costs; compared with the existing copper catalyst, due to the improvement of catalyst selectivity, NO MIBC dehydrogenation device can be added, saving energy consumption and having superiority.
Method for preparation of anti-aging agent 6PPD by using micro-reactor
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Paragraph 0029; 0030; 0031; 0032; 0033; 0034; 0035-0046, (2017/08/25)
The invention discloses a method for preparation of an anti-aging agent 6PPD by using a micro-reactor; a homogeneous solution of p-aminodiphenyl amine and methyl isobutyl ketone and hydrogen gas are subjected to a reaction in a gas-liquid reactor, then are introduced into a solid-liquid reactor and are subjected to a reaction, and the obtained reaction liquid repeats the above operations. Compared with the prior art, the gas-liquid reactor and the solid-liquid reactor are connected in series, the gas-solid-liquid three-phase reaction is performed in a micro-channel, and eventually, the conversion rate of raw materials is improved and the reaction time is shortened. The micro-reactor has the advantages of large specific surface area and strong heat transfer and mass transfer abilities, and enables the reactions to be carried out efficiently; and the reaction temperature, time and material ratio and other conditions can be precisely controlled through the micro-channel reactor, by-products are reduced, and the security is improved.
IMPROVED PROCESS FOR PREPARING 4-AMINODIPHENYLAMINE
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, (2013/09/26)
A process for preparing 4-aminodiphenylamine (4-ADPA) comprising steps of coupling of aniline with nitrobenzene in presence of a suitable base, e.g. tetramethylammonium hydroxide (TMAH), hydrogenation of the coupling mass, phase separation, hydrogenation of azobenzene in the separated organic mass and fractional distillation for 4-ADPA recovery. An improvement in 4-ADPA recovery and a lowering of tar formation are obtained due to azobenzene reduction prior to 4-ADPA isolation. Also a gain in volume productivity of 4-ADPA is obtained by suitably altering the batch cycle time of the coupling reaction.
Tailoring supported palladium sulfide catalysts through H 2-assisted sulfidation with H2S
Xu, Wei,Ni, Jun,Zhang, Qunfeng,Feng, Feng,Xiang, Yizhi,Li, Xiaonian
, p. 12811 - 12817 (2013/10/22)
Supported palladium sulfide catalysts are of great interest in selective hydrogenation reactions. In this work, "Pd4S", "Pd3S", "Pd16S7" and "PdS" supported on activated carbon were selectively synthesized by tailoring the H2-assisted sulfidation of Pd/C with H2S at 150-750°C, and were characterized by means of XRD, XPS, TEM, HRTEM, EDS, BET and H2-TPR techniques. The results indicated that the sulfidation atmosphere, the sulfidation temperature and the metal-support interaction all played important roles in determining the crystal structure and composition of the PdxSy/C catalysts, which in turn gave different catalytic performances in the synthesis of N-(1,3-dimethylbutyl)-N′- phenyl-p-phenylenediamine (6PPD) by the reductive N-alkylation of aromatic amines. PdS/C showed the highest selectivity (>97%) and stability among all the PdxSy/C catalysts.
SULFUR-CONTAINING PALLADIUM-CARBON CATALYST AND METHOD FOR PREPARING AND USING THE SAME
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Page/Page column, (2013/04/10)
A sulfur-containing palladium-carbon catalyst prepared by loading palladium on an active carbon, mixing the palladium-carbon catalyst with a solvent to form a slurry, adding a sulfide to the slurry to treat the loaded palladium under a predetermined temperature, and removing liquid and drying to obtain the catalyst. The sulfur-containing palladium-carbon catalyst is suitable for making phenylene diamine rubber antioxidant with improved productivity and selectivity.
SYNTHESIS SYSTEM, RUBBER CHEMICAL SUBSTANCE FOR TIRES, SYNTHETIC RUBBER FOR TIRES, AND PNEUMATIC TIRE
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Paragraph 0125; 0126, (2013/03/26)
The present invention provides a synthesis system that can synthesize aniline and/or styrene efficiently, a synthesis system that can synthesize butadiene (1,3-butadiene) efficiently, a rubber chemical for a tire which is synthesized from the aniline obtained by the synthesis system, a synthetic rubber for a tire which is synthesized from the styrene and/or butadiene obtained by the synthesis systems, and a pneumatic tire produced using the rubber chemical for a tire and/or the synthetic rubber for a tire. The present invention relates to a synthesis system for synthesizing aniline and/or styrene from an alcohol having two or more carbon atoms via an aromatic compound.
Preparation, structural characterization of a novel egg-shell palladium sulfide catalyst and its application in selective reductive alkylation reaction
Zhang, Qun Feng,Wu, Jia Chun,Su, Chang,Feng, Feng,Ding, Qiao Ling,Yuan, Zhao Lian,Wang, Hong,Ma, Lei,Lu, Chun Shan,Li, Xiao Nian
, p. 1111 - 1114,4 (2020/08/20)
A novel egg-shell Pd-S catalyst with palladium metal as the core and a membrane of palladium sulfide as the surface has been prepared by sulphidizing Pd/C with H2S. This catalyst is effective for the reductive alkylation of p-amino diphenylamine (PADPA) and methylisobutyl ketone (MIBK) to afford N-(1,3-dimethylbutyl)-N′-phenyl-p-phenylenedianine (DBPPD) with conversion up to 99.42% and selectivity to 97.46%. Comparing with the other common palladium sulfide catalysts, the membrane of palladium sulfide on the surface and the core of palladium metal cause the Pd on the surface of the new catalyst in a lower sulfur coordination, which improves its activity. Our result indicates that this new egg-shell Pd-S/C is an efficient hydrogenation catalyst.
METHOD FOR PRETREATING AND USING COPPER-BASED CATALYST
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Page/Page column 4, (2013/02/27)
Method for pretreating the copper-based catalyst having the steps of dehydrating the copper-based catalyst at an elevated temperature, reducing the dehydrated copper-based catalyst with hydrogen, and passivating the activated copper-based catalyst to obtain a catalyst suitable for N-alkylation. The dehydration and reduction steps may be conducted simultaneously.
Stabilization of polymers with styrenated-p-cresols
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, (2008/12/08)
Disclosed herein is a process for the preparation of a mixture of styrenated p-cresol species that is liquid at room temperature and has a viscosity of less than 40,000 cps at 25° C., wherein said process affords 2,6-distyrenated p-cresol assaying at 70% minimum by GC area percent, comprising reacting styrene with p-cresol at a molar ratio of 1.85 to 2.1:1, respectively, in the presence of an acid catalyst at elevated temperature, wherein said mixture comprises monostyrenated-p-cresol, distyrenated-p-cresol, and tristyrenated-p-cresol and exhibits an acid number of less than 0.1 mg KOH/gram.
