The core-shell ZSM-5@InZrMg and ZSM-5@S-1@InZrMg bifunctional catalysts for CO2 hydrogenation to aromatics were prepared by hydrothermal and sol-gel method, respectively. XRD, TEM, N2 adsorption-desorption, NH3-TPD, Py-FTIR, and in situ DRIFTS were used to investigate the effect of distance between two active phases on the hydrogenation performance of CO2 to aromatics. The introduction of Silicalite-1 (S-1) shell inhibited solid ion exchange between In species and ZSM-5. The appropriate distance inhibited the generation of carbon monoxide and promoted the generation of aromatics. Under the conditions of CO2:H2:N2 = 23:69:8, GHSV = 4 L center dot g- 1 center dot h- 1, T = 320 degrees C, and P = 3 MPa, the CO2 conversion reached 3.8 %, the selectivity of CO was 61.9 %, and the space-time yield of aromatics was 0.59 mmol center dot g- 1 center dot h- 1 over the ZSM-5@S-1(1)@InZrMg catalyst. The kinetics results showed the introduction of ZSM-5@S-1(1) reduced the activation energy for CO2 hydrogenation and widened the gap in activation energy for the formation of CO and organic products through rapidly removing the methoxy group and methanol intermediates. In addition, the study of reaction mechanism showed the CO2 hydrogenation to aromatics over ZSM-5@S-1(1)@InZrMg followed formate and dual-cycle pathways.

Zeolite has broad applications in the fields of catalysis and adsorption separation. The conventional batch synthesis process suffers from drawbacks such as low efficiency, complex operation and inconsistent product quality. Therefore, developing reliable and efficient zeolite synthesis routes has become a research hotspot in recent years. Compared to traditional batch reactors, tubular reactor offers superior heat and mass transfer performance, playing a crucial role in process intensification for zeolite synthesis. Continuous synthesis in tubular reactors is a potential effective route, as it not only significantly reduces crystallization time and improves space-time yield but also ensures consistent product quality across batches. Based on recent advances in this field, this review mainly introduces the reactor configurations for continuous zeolite synthesis in tubular systems, discusses the advantages of the synthesis process and product characteristics, clarifies the crystallization mechanisms of zeolites under continuous flow conditions, and especially emphasizes the reasons and solutions to the key problem of pipeline clogging in this process. Furthermore, perspectives on future research and industrial applications are suggested.

The purpose of the olefin hydroformylation-hydrogenation tandem reaction for alcohol synthesis is to design a highly efficient and stable heterogeneous catalyst. In this study, a novel heterogeneous magnetic nanoparticlesupported rhodium-cobalt bimetallic core-shell catalyst was prepared, which exhibits excellent synergistic catalytic performance and enables a one-step alcohol synthesis process. The magnetic support Fe3O4 allows for rapid separation of the catalyst from reaction products under an external magnetic field. The 7.5Co0.5Rh/Fe3O4@SiO2 magnetic core-shell catalyst was successfully prepared by loading active metals via a one-pot impregnation method and performing silica coating using the Sto & uml;ber method. It shows outstanding olefin conversion (99.71%) and alcohol selectivity (91.17%). The effect of preparation conditions, process conditions, and the universality of substrates were investigated in detail. The catalyst was reused 5 times, and the performance differences between the core-shell catalyst and the traditional impregnated catalyst with the same support, as well as the differences in metal leaching during the reaction, were compared. In addition, the catalyst could participate in the reaction directly without prior reduction, avoiding the additional costs associated with subsequent reduction steps.

As the predominant contributor of Br & oslash;nsted acid sites, the spatial distribution of framework aluminum in the ZSM-5 zeolite critically governs its catalytic performance in hydrocarbon conversion reactions, such as cracking, isomerization, and aromatization. This study systematically analyzed the effect of aluminum coordination state on the Al pair formation in ZSM-5 synthesis by the QSP method. A comparative analysis was conducted on six aluminum sources in conjunction with the JMAK kinetic model and multiscale characterization. The results show that the coordination state and spatial distribution of aluminum species directly determine the content and distribution of aluminum pairs in the ZSM-5 zeolite. By increasing the alkalinity of the system, the conversion of Al[(OH2)6]3+ to Al(OH)4 - was promoted and the content of Al pairs increased from 34 to 74%. It was further found that the aluminum source has a significant effect on the crystallization path by adjusting the nucleation energy barrier (E n = 32.23-64.31 kJ/mol) and the growth size. This work illustrates the unique advantages of the QSP method in accurately regulating Al pairs and provides theoretical support for the green synthesis of ZSM-5 catalysts.

InZrO solid solution and Mg modified InZrO catalysts were prepared by using a sol-gel method and the effect of Mg on the hydrogenation of CO2 to methanol was studied in detail by means of XRD, TEM, N2 adsorptiondesorption, FT-IR, XPS, TPD (CO2, H2), H2-TPR, EPR, in situ XRD and in situ DRIFT. The addition of Mg changed the crystal structure and electron property. And a new solid solution MgInZrO was formed, which mainly regulated the catalytic performance by changing the oxygen vacancy and surface -OH group of InZrO solid solution. Furthermore, the presence of Mg also inhibited the decomposition of methanol. Thus, the yield of methanol was increased by 51.70 %. The dynamic kinetics showed the differences in the activation energy between methanol generation and carbon monoxide generation were enlarged. Moreover, the research on reaction mechanism elucidated that the hydrogenation of CO2 over MgInZrO catalyst followed the formate pathway.

Coupling aromatization of methanol with CO was investigated using a two-stage tandem process. It successfully adjusted the product distribution of the first-stage reaction and improved the para-xylene (PX) selectivity over 250 (first-stage and 285@SIO (second-stage). The coupling effects under different reaction conditions were also studied. The argmatics selectivity reached a maximum of 55.3%. The tandem process enhanced the alkylation of aromatics and improved the pX/X and low olefin selectivities. For 285@15P, the pX/X selectivity increased from 22.84% tau omicron 67.49%, and the selectivity of C-2-C reached 42.72%. The ratio of C2/C, C/C and C/C were 93.56 9%, 67.64 % and 46.25 %, respectively. The deactivation of 250 and 285@xP was investigated in detail.

The hydroformylation reaction is very important in industry. However, the leaching of the noble metal Rhodium (Rh) and the separation of homogeneous catalyst have always been difficult problems to solve. And even heterogeneous Rh-base catalyst was developed to solve the separation problem, the serious Rh losing is still hard to avoid. In this work, heterogeneous encapsulated Rh@NaX was prepared by using one-step synthesis method and used as catalyst without reduction in 1-hexene hydroformylation reaction. Rh@NaX catalyst exhibited outstanding catalytic performance. When directly complexed with ligand triphenylphosphine (PPh3), it achieved high heptanal yield of 97.53 %, high n/i ratio of 2.59 and high TOF of 6588 h-1. Interestingly, encapsulated catalyst exhibited higher recycling stability and much lower Rh leaching compared to impregnated catalyst. In addition, in situ XPS and DRIFT analyses were conducted to elucidate the reduction process of Rh and the reaction pathway.

The coaromatization of light alkane and methanol is an attractive nonpetroleum pathway balancing the heat to produce high-value aromatics, but achieving high p-xylene (pX) selectivity is a challenging topic. Here, we present a two-stage tandem catalysis for alkylation intensification. [Zn,Ga]/ZSM-5 was used in the first-stage reactor for the coaromatization to provide sufficient aromatics. The HZSM-5@SiO2 catalysts were prepared for alkylation reaction and characterized by means of X-ray diffraction, N-2 adsorption/desorption, transmission electron microscopy, and Fourier transform infrared with pyridine. The feasibility to enhance xylene and pX was verified by introducing methanol in the second stage to intensify the alkylation of aromatics. Higher SiO2/Al2O3 ratio benefits for xylene and the elimination of external acid sites benefits for pX were found. The pX selectivity and yield and the alkylation efficiency of methanol were significantly increased over HZSM-5@SiO2 in the coaromatization system of n-hexane and methanol. The pX selectivity and yield were increased to 57.41% and 13.12 wt % over Z50@20P. Moreover, the deactivation of HZSM-5@SiO2 was investigated in detail.

Converting coal fly ash (CFA) into zeolite is an alternative way to reduce the solid waste and produce high valueadded products because CFA contains a large amount of Si and Al elements. Here we provide a novel method to synthesize NaX from CFA via a quasi-solid phase (QSP) conversion rather than classical hydrothermal method, in line with the principle of using and discharging as little water as possible. The pretreatment by HCl and NaOH, the effects of some important factors such as molar ratio of H2O to SiO2, seed amount, crystallization temperature and time were investigated to optimize the process. It's exciting that the NaX with high crystallinity was obtained under optimal conditions when the molar ratio of H2O to SiO2 was only 8. In addition, the water retention performance of NaX in sand was studied, showing a possibility of desertification control using synthesized zeolite from CFA.

A hollow zeolite encapsulated Rh catalyst Rh@H-S-1 with an "eggshell" structure was prepared using the method of organic alkali treatment and recrystallization. Compared with catalysts with directly encapsulated Rh@S-1 and surface impregnated Rh/S-1, this catalyst exhibited both superior activity and a higher TOF value in hydroformylation of 1-hexene due to the high dispersion of Rh and high diffusion. The Rh element did not need to be reduced in the preparation, and it was in situ reduced by the syngas. The content of lower valence Rh delta+ gradually increased with the reaction procedure and played as an active center. The low oxidized state Rh+ or Rh(delta+ )in the form of Rh(CO)(2) are proposed as active sites in hydroformylation, which were generated under the synergistic effect between CO and H-2. Importantly, the hollow encapsulated catalyst effectively decreased Rh leaching to 0.1 ppm and showed better stability compared with the impregnated Rh/S-1 catalyst.

Ce modified Zn/ZSM-5 catalyst was prepared and the effect of Ce promotor on coaromatization of methanol and n -hexane was studied. The physical and chemical properties of Zn -Ce/HZ were tested by XRD, XPS, TEM, N 2 adsorption-desorption and Py-FTIR. The loading of Ce tuned the acidity distribution and increased the LAS/BAS ratio, and mainly reduced the microporous specific surface area. Most of Zn and Ce elements entered the zeolite channels. The loading of Ce enhanced the interactions between Zn species and support and significantly increased the numbers of active centers of ZnOH + species. Under the optimized conditions, the yield of aromatics was greatly improved from 25.2 % of HZ to 62.6 %. The reasons of deactivation were also analyzed. The higher the aromatization activity, the more the formed carbon deposit. The blockage of micropores and the greatly coverage of acid sites by carbon deposit thus resulted in poor catalytic performance.

The products with higher carbon numbers from Fischer-Tropsch (F-T) synthesis are very complex and hard to directly be analyzed on GC due to their very high boiling point. In this work, the qualitative and quantitative analytical method for refined F-T wax samples with C7 to C38 was established on GC-MS. All components were well separated, qualified and quantified. The analytical errors were less than +/- 2 % and the errors of recovery experiments were less than +/- 5 %. Thereafter, this method was successfully applied in GC analysis with errors less than +/- 0.75 % and the analytical method on GC was also built, which will provide a more convenience way in analysis of refined F-T wax samples. Based on the obtained analytical conditions and the relative calibration factors of paraffins, the qualitative and quantitative method for the cracking products from refined F-T wax was further built according to a similar method by using simulated samples with the conversion from 5 % to 80 %. The thermal cracking of F-T wax 5# was performed and the content of LAOs in liquid mixtures reached over 50 % at 650 degrees C. This study simplifies the previous analysis methods which can only be completed by using a variety of standard methods and provide convenience for analysis of refined F-T wax from coal-to-liquid plant.

P/[ZnCr]/HZSM-5 showed a higher BTEX yield of 87.5 wt% and higher stability due to less coke in the coaromatization of methanol coupling with n-hexane.

Zn and Mo modified HZSM-5 catalyst benefits the formation of aromatics and the yield of BTX reached 64%. The influence of Mo content on the catalytic performance and carbon deposit were investigated in detail.

基于中国知网数据库(CNKI)和科学引文数据库(WoS),采用知识图谱方法对甲酵制芳烃领域的合作作者、共词网络及关键词聚类进行了分析,归纳了该领域目前主要的研究方向及内容,展望了芳构化反应今后的研究方向.

A series of [Zn,Ga]/HZ catalysts were prepared by impregnation and their catalytic performance in coaroma-tization of n-hexane and methanol, a heat-coupling reaction, were studied in detail. The crystallization, textural properties, morphology, acidity, composition and chemical state were characterized by XRD, N2 adsorption/ desorption isotherms, TEM, py-FTIR, ICP-OES and XPS. The modification of Zn and Ga tunes the acid distri-bution, and more importantly Ga introduction greatly increases the content of active centers Zn(OH)+ from 30 % (1Zn/HZ) to 60 %. As a result, [Zn,Ga]/HZ improves the dehydroaromatization ability and provides higher aromatics yield. The analysis of organic species in catalyst by TG and GC-MS confirms that [Zn,Ga]/HZ produces more aromatics precursors than HZ. Under the conditions of feed ratio (n-hexane/methanol) 3:7, reaction temperature 530 degrees C, and WHSV 1.0 h-1, the BTX yield was significantly increased to 70 %.

四环素废水会对周围水体和土壤环境造成严重污染,针对其组成复杂和难降解的特点,先通过活性炭去除废水中杂质和部分四环素,再经过Cu-13X分子筛选择性吸附以进一步去除四环素.本文采集四环素制药废水(295.3mg/L)为研究对象,单一活性炭C(f)(1g)对四环素去除率达到50.2％,联合Cu-13X(S4,0.1g)后去除率达到了99.3％,TOC降低了2067.7mg/L.Cu-13X经五次循环再生-吸附后,去除率保持在99.8％左右.

A Mn-modified ZSM-5 zeolite (Mn-HZ) was synthesized using a quasi-solid-phase method, and its physicochemical properties were characterized. The presence of tetracoordinated framework Mn(III) was confirmed using ultraviolet-visible and Raman spectroscopy measurements, X-ray photoelectron spectroscopy, and H-2- temperature programmed reduction, and the results suggest that Mn entered the framework structure of ZSM-5. Crucially, the introduction of Mn increased the weak Bronsted acid site content and decreased the strong acid site content and resulted in an increase in the amount of framework Al in the straight zeolite channels. During application for the methanol-to-propylene reaction (MTP), Mn-HZ produced fewer aromatics and had a lower carbon deposition rate than the unmodified zeolite, resulting in a longer catalyst lifetime and higher selectivity for propylene and butene. In addition, a mechanism for the MTP reaction is proposed based on the detection of ethylene in high concentrations in the initial stages of the reaction, suggesting that it could be the initial hydrocarbon pool species. Overall, our results indicate that Mn-HZ favored the olefin-based cyclic mechanism to the aromatic-based mechanism.

The steam cracking of Fischer-Tropsch refined wax from the coal-to-oil process for producing linear α-olefin (LAO) was carried out on a fixed bed reactor. The effects of feedstock composition, cracking temperature, contact time, water-to-wax ratio and cyclic process on the feed conversion and products distribution were investigated and optimized. The factors such as cracking temperature and contact time have significant influence on conversion and LAO yield, and cyclic process can further improve the LAO yield. However, excess high cracking temperature and longer contact time result in the second reactions, which are unfavorable for the LAO production. Under the suitable process conditions 53% of LAO yield are obtained.

线性α-烯烃(LAO)是非常重要的有机化工原料和中间体,应用范围广泛,近年来在国内外的需求量逐年增高,其生产工艺是行业内关注的重点.介绍了LAO近年来的供需状况,并对国内外α-烯烃的主要生产工艺进行了综述,阐述了不同工艺的流程、特点及进展.结合我国资源特点,提出了"以大力投入乙烯齐聚工艺为主、以费托蜡裂解和生物质能源路线为保障"的LAO生产工艺发展方向.