期刊文献+
共找到12篇文章
< 1 >
每页显示 20 50 100
Environmentally-Friendly Catalytic Oxidation of Cyclohexanone with 30% H_2O_2 Solution: A Comparison Study between Hollow Titanium Silicate and Dealuminated HBEA Zeolites 被引量:2
1
作者 Xia Changjiu Zhao Yi +4 位作者 Zhu Bin Lin Min Peng Xinxin Dai Zhenyu Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2018年第4期8-19,共12页
Two clean liquid–phase cyclohexanone oxidation routes catalyzed by DHBEA and HTS zeolites, in the absence of organic solvents, have been developed for producing high value-added chemical intermediates. Under optimize... Two clean liquid–phase cyclohexanone oxidation routes catalyzed by DHBEA and HTS zeolites, in the absence of organic solvents, have been developed for producing high value-added chemical intermediates. Under optimized conditions,the cyclohexanone conversion reaches up to 60%, and the selectivity of total target products(ε-caprolactone, 6-hydroxyhexanoic acid and adipic acid) is over 90% achieved by the HTS zeolite; while both cyclohexanone conversion and the 6-hydroxyhexanoic acid selectivity are over 95% obtained on the DHBEA zeolite. Both the Lewis and Br鰊sted acid sites of DHBEA zeolite can preferentially activate the carbonyl group of cyclohexanone without any impact on H_2O_2 molecules.Meanwhile, the HTS zeolite can predominantly make H_2O_2 more reactive, which agrees well with the molecular calculation results. Hence, two different Baeyer-Villiger oxidation mechanisms based on the activation of H_2O_2 and cyclohexanone are proposed. Then, 6-hydroxyhexanoic acid is formed via the ring-opening of ε-caprolactone. However, C-OH groups cannot be reactivated by DHBEA zeolite, leading to insignificant adipic acid formation, while the selectivity of adipic acid is 28.5% obtained on the HTS zeolite. Consequently, the higher catalytic performance of the DHBEA zeolite is ascribed to its larger amount of active sites and greater diffusion features than those of HTS zeolite. 展开更多
关键词 HOLLOW titanium SILICATE CYCLOHEXANONE oxidation ZEOLITE Baeyer-Villiger molecular calculation
在线阅读 下载PDF
Insights into the Reaction Network and Mechanism of Green Aerobic Oxidative Esterification of Methacrolein over Different Heterogeneous Catalysts 被引量:1
2
作者 Li Chenhao Xia Changjiu +7 位作者 Liu Yujia Huang Kaimeng Peng Xinxin Liu Jinsheng Lin Min Zhu Bin Luo Yibin Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2021年第3期1-11,共11页
The oxidative esterification of methacrolein(MAL)is an important way to prepare high-valued methyl methacrylate(MMA),but this process is ultra-complex due to the high reactivity of both C=O and C=C bonds in MAL molecu... The oxidative esterification of methacrolein(MAL)is an important way to prepare high-valued methyl methacrylate(MMA),but this process is ultra-complex due to the high reactivity of both C=O and C=C bonds in MAL molecule.In order to further improve MMA selectivity,the reaction network and relevant mechanisms have been proposed and profoundly investigated in this paper.Five kinds of fundamental reactions are involved in this process,including(a)the acetal reaction;(b)the aerobic oxidation of hemiacetal;(c)the alkoxylation of C=C double bond;(d)the Diels-Alder reaction;and(e)the hydrogenation reaction of unsaturated double bond.Among them,the Diels-Alder reaction of MAL is non-catalyzed,and the Brönsted acid sites or the Lewis acid sites favor promoting acetal reaction of MAL with methanol,while the alkoxylation of C=C bond with methanol is enhanced under alkaline condition.In particular,by employing the Pd-based catalysts,hydrogenation products are formed in alkaline methanol solution,hence with lower than those obtained by the Au-based catalysts.Notably,it is necessary to match the hemiacetal fromation and aerobic oxidation of hemiacetal,which is relevant with the amount and strength of acid and redox sites.Consequently,this work can provide a good guidance for the further design of both catalysts and processes in future. 展开更多
关键词 METHACROLEIN oxidative esterification MECHANISM reaction network methyl methacrylate
在线阅读 下载PDF
Identification of Ni_xS_y on Industrial Spent S Zorb Sorbents by Using XPS and TPR-MS 被引量:2
3
作者 Yuan Hui Qiu Limei +4 位作者 Xu Guangtong Xin Mudi Shi Yanqiang Chen Shuai Zou Kang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2018年第3期42-47,共6页
Three industrial spent S Zorb sorbents extracted from production line were studied with XRD, TPR-MS and XPS. The characterization results of XPS and TPR-MS identified the existence of amorphous Ni_xS_y on industrial s... Three industrial spent S Zorb sorbents extracted from production line were studied with XRD, TPR-MS and XPS. The characterization results of XPS and TPR-MS identified the existence of amorphous Ni_xS_y on industrial spent S Zorb sorbents, while the existing XRD quantitative analysis methods can only provide the long-range order in phase information and the grain size of Ni metal. XPS is a powerful tool to investigate the chemical states of nickel atom and the depthwise distribution of nickel species on S Zorb sorbent. Ni_xS_y and Ni metal species coexist on the industrial spent sorbents, and their percentages to total nickel slightly change with the operating conditions in the surface layer. It proves that Ni_xS_y is a stable intermediate product rather than a transition state. The information can contribute to the better elucidation of S Zorb desulfurization mechanism and offer a new direction for selectivity optimization of industrial S Zorb sorbents. 展开更多
关键词 S Zorb SORBENT nickel sulfide reaction mechanism X-ray photoelectron spectroscopy
在线阅读 下载PDF
Synthesis of IM-5 Zeolite by Template Pre-Reaction
4
作者 Sun Min 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2021年第2期77-83,共7页
IM-5 zeolite was synthesized by hydrothermal crystallization method with 1,5-bis(N-methylpyrrolidinium)pentane bromide using the precursors N-methylpyrrolidine and 1,5-dibromopentane as raw materials of template after... IM-5 zeolite was synthesized by hydrothermal crystallization method with 1,5-bis(N-methylpyrrolidinium)pentane bromide using the precursors N-methylpyrrolidine and 1,5-dibromopentane as raw materials of template after pre-reaction,and then aluminum,alkali,water and silicon sources were added into the reaction system.The effects of the proportion of precursors and other materials and the reaction conditions on the crystallinity,crystal morphology and pore structure of the synthesized zeolites were systematically investigated,which provided the basic data for industrial production.The physical properties of the synthesized samples were analyzed by XRD,SEM,and N2 adsorptiondesorption techniques,and the catalytic performance of the samples was evaluated.The results show that IM-5 zeolite can be synthesized effectively by using the template pre-reaction method,and its physical properties and catalytic activity in catalytic alkylation of benzene and methanol are comparable to those of industrial samples synthesized by traditional method. 展开更多
关键词 IM-5 zeolite TEMPLATE PRE-REACTION catalytic performance
在线阅读 下载PDF
A “Green” Cyclohexanone Oxidation Route Catalyzed by Hollow Titanium Silicate Zeolite for Preparing ε-Caprolactone,6-Hydroxyhexanoic Acid and Adipic Acid 被引量:5
5
作者 Xia Changjiu Zhu Bin +1 位作者 Lin Min Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期33-41,共9页
Hollow titanium silicalite (HTS) molecular sieve has been synthesized, and information on its structure, physico- chemical characterization, as well as surface property was investigated by a host of analytical metho... Hollow titanium silicalite (HTS) molecular sieve has been synthesized, and information on its structure, physico- chemical characterization, as well as surface property was investigated by a host of analytical methods, such as XRF, XRD, low-temperature N2 adsorption/desorption, TEM, FT-IR, UV-Vis, 29Si MAS NIVIR, and XPS techniques. The characterization results suggest that HTS zeolite has a special hollow crystal structure and its mesopore volume is larger than that of TS-1 zeolite. The titanium species in this zeolite are composed of the framework tetrahedral Ti (IV) ions and extra-framework octahedral Ti (IV) ions, which tend to disperse into its bulk phase. This zeolite material also has been applied to catalyze the cyclohexanone oxidation process, and the products are not completely consistent with those results obtained by using TS-1 zeolite, which might be caused by their difference in pore structure and pore volume, especially the mesopore volume. Cy- clohexanone oxidation catalyzed by HTS zeolite is a representative consecutive reaction, the main target products of which are e-caprolactone, 6-hydroxyhexanoic acid and adipic acid. The effect of H202/cyclohexanone mole ratio on the cyclohexa- none conversion, the total target product selectivity, the distribution of three target products selectivity and their variations along with reaction time is also researched and analyzed, which indicate that HTS zeolite shows a high performance for the Baeyer-Villiger reaction of cyclohexanone and catalytic oxidation of 6-hydroxyhexanoic acid under mild conditions, and the quantity of active surface titanium species as well as the pore structure and mesopore volume controlling the mass diffusion rate are the key factors determining the catalytic activity of HTS zeolite and product selectivity. 展开更多
关键词 catalytic oxidation CYCLOHEXANONE HTS zeolite Baeyer-Villiger reaction consecutive reaction
在线阅读 下载PDF
Study on the Mechanisms for Baeyer-Villiger Oxidation of Cyclohexanone with Hydrogen Peroxide in Different Systems 被引量:4
6
作者 Xia Changjiu Lin Min +1 位作者 Zhu Bin Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第2期7-17,共11页
The green and effective Baeyer-Villiger oxidation reaction of cyclohexanone for preparing e-caprolactone is of particular importance in the synthesis of new polymer materials. We have discussed here several mechanism ... The green and effective Baeyer-Villiger oxidation reaction of cyclohexanone for preparing e-caprolactone is of particular importance in the synthesis of new polymer materials. We have discussed here several mechanism types of Baeyer-Villiger oxidation of cyclohexanone with H2O2 in different reaction systems. Five main types have been addressed, i. e.: (1) the non-catalyzed reaction type, where the C=O of ketones is activated by H+, which is electrolytically dissociated from H202 and H20, to improve the capability of C=O group for accepting the electron pairs; (2) the thermally activated radical reaction type, where the Criegee intermediate is produced via two steps of radical reaction with -OH attack, with much more hydroxyl radicals being excited in the presence of TS-1 zeolite; (3) the Bronsted acid catalysis reaction type, where both O-O moiety and C=O group could be activated by BriSnsted acid; (4) the solid Lewis acid catalyzed C=O of the substrate activation reaction type through enhancing the donor-acceptor interaction between the antibonding π*c-o orbital of cyclohexanone and HOMO of Sn-containing zeolites; and (5) the solid Lewis acid catalyzed H202 to form Me-OOH oxidative species by converting the highest occupied molecular orbital (HOMO) of Ti-OOH into a singly occupied molecular orbital (SOMO), making the O--O group highly electrophilic to attack the C--O of cyclohexanone during the Baeyer-Villiger oxidation process. In the end, we have also compared the different mechanisms and put forward our opinions on the development direction of catalytic materials aiming at eco-friendly Baeyer-Villiger oxidation of cyclohexanone in the years to come. 展开更多
关键词 reaction mechanism Baeyer-Villiger oxidation Lewis acid Br'6nsted acid thermally activated radical hydrogen peroxide
在线阅读 下载PDF
Regeneration of Simulated Deactivated Hollow Titanium Silicate Zeolite by Secondary Crystallization in the TPAOH Solution 被引量:3
7
作者 Xia Changjiu Lin Min +3 位作者 Peng Xinxin Zhu Bin Xu Guangtong Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2017年第1期1-10,共10页
It is of paramount importance to improve the utilization efficiency of hollow titanium silicate(HTS) zeolite catalyst used in the cyclohexanone ammoxidation process. To achieve this aim, the regeneration of simulated ... It is of paramount importance to improve the utilization efficiency of hollow titanium silicate(HTS) zeolite catalyst used in the cyclohexanone ammoxidation process. To achieve this aim, the regeneration of simulated deactivated HTS zeolite by post-synthesis was carried out in an aqueous TPAOH solution under hydrothermal conditions. It was found that the catalytic performance for phenol hydroxylation over regenerated HTS zeolite was as high as that of fresh one.Judging from the BET measurements, electron micrography and XRD analysis results, it was confirmed that the topological and morphological structure was repaired. The chemical state of Ti species was detected by the UV-Vis and ^(29)Si MAS NMR spectroscopy. No acidic amorphous TiO_2-SiO_2 oxide was formed, and the extraframework Ti species could be reincorporated into the framework of HTS zeolite thanks to the tetrahedral coordination by the condensation between Ti-OH and Si-OH groups. In order to confirm this conclusion, the fresh HTS zeolite was treated under the NH_3·H_2O hydrothermal and thermal conditions for several times. The catalytic activity of both uncalcined and calcined simulated deactivated HTS zeolite samples could be regenerated without the formation of Br?nsted acid sites. It was concluded that the highly dispersed Ti species could be reincorporated into the framework of zeolite by hydrated condensation of Si-OH and Ti-OH groups after secondary hydrothermal synthesis. 展开更多
关键词 hollow titanium silicate REGENERATION post synthesis TEM TEMPLATE
在线阅读 下载PDF
Investigation on Organic Solvent Free Toluene Oxidative Bromination Reaction Catalyzed by HTS Zeolite 被引量:2
8
作者 Peng Xinxin Xia Changjiu +3 位作者 Lin Min Zhu Bin Luo Yibin Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2020年第4期1-9,共9页
The toluene oxidative bromination reaction catalyzed by hollow titanium silicalite(HTS)zeolite in aqueous medium was investigated by employing H2O2 and HBr under mild conditions without the need for organic solvent.A ... The toluene oxidative bromination reaction catalyzed by hollow titanium silicalite(HTS)zeolite in aqueous medium was investigated by employing H2O2 and HBr under mild conditions without the need for organic solvent.A high toluene conversion(90.7%)and high selectivity of mono-bromotoluene(99.0%)was achieved under the optimal reaction conditions.The UV-Raman spectroscopy was applied for the mechanism study and the result reveals that HTS is efficient for catalyzing the oxidation reaction of HBr with H2O2 to produce abundant active bromine species,which can further facilitate the toluene electrophilic bromination reaction.A two-step toluene bromination reaction mechanism involving the HTS catalyzed active bromine species“generation-conversion-utilization”process is proposed based on the UV-Raman spectroscopy analysis. 展开更多
关键词 titanium silicalite oxidative bromination organic solvent free H2O2/HBr polybromine ion
在线阅读 下载PDF
Effect of Zeolite 5A Particle Size on Its Performance for Adsorptive Separation of Ethylene/Ethane 被引量:1
9
作者 Bian Qingmin Xin Mudi +3 位作者 Xu Guangtong Chen Shuai Zou Kang Shi Yanqiang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2019年第4期36-41,共6页
The adsorptive separation of ethylene from ethane exhibits a less energy-intensive-alternative technique with development potential among all processes for separation of ethylene/ethane currently. In this approach, ze... The adsorptive separation of ethylene from ethane exhibits a less energy-intensive-alternative technique with development potential among all processes for separation of ethylene/ethane currently. In this approach, zeolite 5 A with different particle sizes ranging from 3 340 nm to 440 nm was prepared by hydrothermal synthesis. The effect of particle size on the adsorptive separation performance of zeolite 5 A was investigated. The results show that the particle size has a significant effect on the ethylene IAST(Ideal Adsorbed Solution Theory) selectivity of zeolite 5 A. The zeolite 5 A with a particle size of 710 nm demonstrated the highest ethylene selectivity(5.6). The relatively high crystallinity of zeolite 5 A is in favor of massive adsorption capacities of ethylene and ethane. 展开更多
关键词 zeolite 5A particle sizes adsorptive separation ETHYLENE ETHANE
在线阅读 下载PDF
Effects of Recrystallization Parameters on the Formation of Hollow Silicalite-1 Zeolite 被引量:1
10
作者 Tan Cheng Dong Zhuoya +4 位作者 Sun Tu Zhang Yaping Zhang Guanqun Xia Changjiu Ma Yanhang 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2019年第4期1-8,共8页
Hollow silicalite-1 zeolite can be readily fabricated by hydrothermally treating the parent silicalite-1 with tetrapropylammonium hydroxide. A dissolution-recrystallization mechanism has been previously proposed to ex... Hollow silicalite-1 zeolite can be readily fabricated by hydrothermally treating the parent silicalite-1 with tetrapropylammonium hydroxide. A dissolution-recrystallization mechanism has been previously proposed to explain the formation of such hollow structures, but detailed information of this formation process still remains unclear. Herein, by tracking the evolvement of the hollow voids and morphology of the silicalite-1 under various treatments using XRD, SEM, TEM and N2 adsorption/desorption techniques, we systematically studied the formation process of the hollow structure of silicalite-1 zeolite and discovered that the organic template, water, treating temperature and time can significantly influence the morphology and size of hollow structure inside silicalite-1 zeolite crystals. Generally, a diluted synthesis medium with high template content under suitable temperature(for instance 170 °C) and extended treatment time favors the formation of single hexagonal hollow structure within silicalite-1 zeolites;while other conditions favor the formation of rounded hollow voids or even multiple-voids within silicalite-1 zeolites. 展开更多
关键词 hollow silicalite-1 hydrothermal synthesis dissolution recrystallization
在线阅读 下载PDF
Deactivation Behavior of Hollow Titanium Silicalite Zeolite in Aqueous Ammonia Solution under Simulated Industrial Cyclohexanone Ammoximation Conditions 被引量:2
11
作者 Xia Changjiu Lin Min +3 位作者 Peng Xinxin Zhu Bin Xu Guangtong Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2016年第4期1-10,共10页
For simulating the real deactivation of hollow titanium silicalite(HTS) zeolite in commercial ammoximation process, HTS was treated by 10% NH_3·H_2O solution at 120 ℃ in stirred autoclave. It is found that a par... For simulating the real deactivation of hollow titanium silicalite(HTS) zeolite in commercial ammoximation process, HTS was treated by 10% NH_3·H_2O solution at 120 ℃ in stirred autoclave. It is found that a part of HTS zeolite crystals dissolved in the hot NH_3·H_2O solution, and the specific surface area and pore volume continuously decreased with the increase in NH_3 hydrothermal treatment time. Meanwhile, the transformation of framework Ti species into extraframework Ti species was detected by the spectroscopic methods. However, the extraframework Ti species were still in a highly dispersed state after the hydrothermal and thermal treatments as shown by TEM images, while the formation of new acid sites was not detected. Upon combining the results of characterization with catalytic performance of HTS, the main deactivation reason for this material had been determined, which might be attributed to the reduction of specific surface area and active centers after basic treatment and calcination of HTS samples. And then the possible mechanism of simulated deactivation of HTS zeolite was proposed, which could describe the elemental reaction steps much more visually and directly. 展开更多
关键词 deactivation hollow titanium silicate ammoximation extraframework Ti TEM
在线阅读 下载PDF
One-pot Synthesis of 6-Hydroxyhexanoic Acid from Cyclohexanone Catalyzed by Dealuminated HBEA Zeolite with Aqueous 30% H_2O_2 Solution
12
作者 Xia Changjiu Yang Yongjia +6 位作者 Zhao Yi Lin Min Zhu Bin Peng Xinxin Dai Zhenyu Luo Yibin Shu Xingtian 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2018年第3期1-6,共6页
The one-pot synthesis of 6-hydroxyhexanoic acid from cyclohexanone via the integrated Baeyer-Villiger oxida-tion and ring opening reaction catalyzed by dealuminated HBEA zeolite has been developed. Under optimized con... The one-pot synthesis of 6-hydroxyhexanoic acid from cyclohexanone via the integrated Baeyer-Villiger oxida-tion and ring opening reaction catalyzed by dealuminated HBEA zeolite has been developed. Under optimized conditions,the cyclohexanone conversion and 6-hydroxyhexanoic acid selectivity are over 95%, respectively. The excellent catalyticperformance is attributed to the activation of carbonyl group of cyclohexanone and the fast hydrolysis and ring opening ofs-caprolactone by both Lewis acid and Br0nsted acid sites under aqueous conditions. 展开更多
关键词 Baeyer-Villiger oxidation cyclohexaxlone 6-hydroxyhexanoic acid ZEOLITE HYDROLYSIS
在线阅读 下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部