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| 1 | Mass transfer model,preparation and applications of zeolite membranes for pervaporation dehydration:A review显示文摘Pervaporation(including vapor permeation) is a kind of new membrane separation technology, possessing the advantages of high efficiency, energy saving and convenient operation. It has promising application in the separation and purification of organic solvents. Dehydration is an important step in the production and recovery of organic solvents. Zeolite membranes have attracted wide attention for pervaporation dehydration due to their high separation performance and good thermal/chemical stability. So far, zeolite membranes have been preliminarily industrialized for dehydration of organic solvents. This paper reviews the recent development of zeolite membranes for pervaporation dehydration, including mass transfer models, preparation and applications of zeolite membranes. The review also discusses the current industrial applications of zeolite membranes and their future development in pervaporation. | Chun Zhang Li Peng Ji Jiang Xuehong Gu | 2017 | Chinese Journal of Chemical Engineering2017，25，11： | 11 |
| 2 | Enhanced aromatic selectivity by the sheet-like ZSM-5 in syngas conversion显示文摘Aromatics are important basic chemicals. However, direct conversion of syngas via the conventional Fischer-Tropsch synthesis produces little aromatics. We presented herein that a bifunctional composite of ZSM-5 in combination with Zn Cr Oxcatalyzes syngas conversion to aromatics. Particularly, ZSM-5 crystals with a sheet-like morphology can enhance significantly the aromatization activity. The lower length ratio of the b/a axes of the crystals, the more aromatics form but without influencing the selectivity of small molecules such as CH4 and C2–C4. Since the acid properties and the Al chemical environment were not altered while the morphology changed, the enhanced aromatic selectivity is likely attributed to the favored diffusion of aromatics in these sheet-like crystals. | Junhao Yang Ke Gong Dengyun Miao Feng Jiao Xiulian Pan Xiangju Meng Fengshou Xiao Xinhe Bao | 2019 | Journal of Energy Chemistry2019，28，8： | 10 |
| 3 | Impacts of nitrogen and zeolite managements on yield and physicochemical properties of rice grain显示文摘Zeolite(Z)can hold soil water and nutrient to obtain a higher yield on introduction into moist soil.However,the effects of Z and nitrogen(N)managements on rice grain quality is unclear.Therefore,the effects of different amounts of Z(Z0:0 t/hm^(2);Z0.9 and Z0.22:10 t/hm^(2)in different particle sizes of 0.45-0.9 mm and 0.17-0.22 mm in diameter)and N(N0,N52.5,N105,N157.5:0 kg/hm^(2),52.5 kg/hm^(2),105 kg/hm^(2),157.5 kg/hm^(2)),and Z(Z0,Z10:0 t/hm^(2),10 t/hm^(2))and application frequencies of N on rice yield and grain quality were investigated in 2014 and 2015 in Northeast coastal region of China where Z10 was extended to use in large areas.Results showed that both N and Z applications significantly increased the yields of rough rice(RRY),brown rice,milled rice and head rice.However,there was no significant difference between Z0.9 and Z0.22.The chalkiness area,length-width ratio and head rice rate were not influenced by Z and N applications.However,Z application significantly decreased the chalk rate and slightly increased amylose content(AC)but mattered little to taste value(TV)of rice and rice cooking quality.N could significantly increase rice protein content(PC)but lessen the TV and breakdown value;the order of influence degree on rice yield increasing was as follows:CRF2(third-split fertilization with Z10),CRF1(basal fertilization one time with Z10),U2(urea:third-split fertilization without Z)and U1(basal fertilization one time without Z).Both CRF1 and CRF2 greatly enhanced the RRY.However,CRF1 was recommended for clear decrease in labor and fuel for growers.Compared with treatments of U1 and CRF1,CRF2 and U2 significantly decreased the AC.PC exhibited significant negative relation to TV and greatly determined the rice eating quality and cooking quality. | Wu Qi Xia Guimin Chen Taotao Chi Daocai Jin Ye Sun Dehuan | 2016 | International Journal of Agricultural and Biological Engineering2016，9，5： | 10 |
| 4 | A review of the synthesis and application of zeolites from coal-based solid wastes显示文摘Zeolite derived from coal-based solid wastes(coal gangue and coal fly ash)can overcome the environmental problems caused by coal-based solid wastes and achieve valuable utilization.In this paper,the physicochemical properties of coal gangue and coal fly ash are introduced.The mechanism and application characteristics of the pretreatment processes for zeolite synthesis from coal-based solid wastes are also introduced.The synthesis processes of coal-based solid waste zeolite and their advantages and disadvantages are summarized.Furthermore,the application characteristics of various coal-based solid waste zeolites and their common application fields are illustrated.Finally,we propose an alkaline fusion-assisted supercritical hydrothermal crystallization as an efficient method for synthesizing coal-based solid waste zeolites.In addition,more attention should be given to the recycling of alkaline waste liquid and the application of coal-based solid waste zeolites in the field of volatile organic compound adsorption removal. | Xiaoyu Zhang Chunquan Li Shuilin Zheng Yonghao Di Zhiming Sun | 2022 | International Journal of Minerals,Metallurgy and Materials2022，29，1： | 10 |
| 5 | Low-temperature selective catalytic reduction of NO_(x) with NH_(3) over zeolite catalysts:A review显示文摘The selective catalytic reduction(SCR)of NO_(x) by NH3 is one of the most mature technologies for NO_(x) treatment.Catalysts are the main factors affecting denitrification efficiency.Zeolites as low-tempe rature NH3-SCR catalysts have been extensively studied in the past few years.In this work,the mechanism of zeolites for NH3-SCR reaction was reviewed and the denitrification performances of zeolite catalysts prepared by different methods were compared.The effects of sulfur and water poisoning on zeolite catalysts in NH3-SCR reaction were also analyzed.Several ways to address the problems in lowtemperature NH3-SCR reaction were discussed.Hopefully,this review could provide a fundamental understanding of SCR reaction on zeolite catalysts and pave the way toward similar studies to realize its commercial applications. | Yijuan Pu Xinyu Xie Wenju Jiang Lin Yang Xia Jiang Lu Yao | 2020 | Chinese Chemical Letters2020，31，10： | 9 |
| 6 | The essential mass transfer step in hierarchical/nano zeolite: surface diffusion显示文摘An important topic in zeolite catalyst design is how to improve utilization efficiency o f active sites in micropores by upgrading the effective diffusivity o f reactants/products in zeolite crystal particles[l].Nano-and hierarchical structures have drawn lots of attention in zeolitic catalysis fields in recent years;because these two methods can obviously improve the catalysis efficiency by shortening the configuration diffusion length[2].However,new problems were raised in the construction process of hierarchical or nano-zeolites.For instance,it was found that the hierarchical structure can change the intrinsic properties of surface acid sites in zeolite[3].Fan et al.reported that when the length scale o f the zeolite approaches several nanometers;the difFusional time constants[4,5]and the apparent configuration diffusion lengths will be significantly increased than expected[6].Therefore,enhanced mass transport in hierarchical zeolite will be overpredicted if not considering the extent of sorbate-sorbent interaction. | Jian Zhou Wei Fan Yangdong Wang Zaiku Xie | 2020 | National Science Review2020，7，11： | 7 |
| 7 | Synthesis of MOR/SAPO-11 Composite Molecular Sieve via Seed Crystallization for n-Alkane Hydroisomerization显示文摘n-Alkane isomerization is a critical reaction that can affect parameters in oil refining, such as the gasoline octane number and diesel oil solidifying point. In this study, a catalyst support, mordenite (MOR)/silicoaluminophosphate (SAPO)-11 composite zeolite with core/shell structure, was synthesized by hydrothermal method with MOR acting as the seed for crystallization. The crystal structure, elemental composition, surface area, pore volume, and acidity of the catalyst was thoroughly characterized. In addition, the catalytic performance of the as-obtained Pt/MOR/SAPO-11 in the hydroisomerization of n-dodecane was tested. The results indicated that the properties and catalytic performance of the composite molecular sieve were quite different from those of the pure zeolites and physical mixture of MOR and SAPO-11 (MOR+SAPO-11). Compared with the physical mixture, MOR and SAPO-11 were more tightly bound in MOR/SAPO-11 because of chemical bonding. Moreover, the acidity and pore structure were favorable to the catalytic hydroisomerization of n-dodecane. Pt/MOR/SAPO-11 exhibited higher isomerization activity than the Pt-loaded pristine MOR and MOR+SAPO-11. Thus, the core-shell composite molecular sieve has promising industrial applications as the catalyst support. | Sun Na Wang Haiyan Ma Yuxiang Yang Zhanxu Kang Lei | 2019 | China Petroleum Processing & Petrochemical Technology2019，21，2： | 6 |
| 8 | Catalytic activity of Cu-SSZ-13 prepared with different methods for NH_3-SCR reaction显示文摘A series of Cu-SSZ-13 catalysts with the same Cu loading were prepared by different methods of incipient wetness impregnation [Cu-SSZ-13(IWI)], ion exchange[Cu-SSZ-13(IE)] and hydro-thermal synthesis [Cu-SSZ-13(HTS)]. Their activity for selective catalytic reduction of nitrogen oxides(NO_x) with NH3 was determined. The results show that the Cu-SSZ-13(HTS) catalyst exhibits a better ammonia selective catalytic reduction(NH3-SCR)activity compared with the other two catalysts, over which more than 90% NO conversion is obtained at 215-600℃under the space velocity of 180,000 h^(-1). The characterization results reveal that the Cu-SSZ-13(HTS) catalyst possesses more amount of stable Cu^(2+) in the six-membered ring and high ability for NH3 and NO adsorption, leading to its high NH3-SCR activity, although this catalyst has low surface area. On the other hand, the activity of Cu-SSZ-13(IE) catalyst is almost the same as that of Cu-SSZ-13(IWI) catalyst at the temperature lower than 400 ℃, but the activity of the former is much higher than that of the latter at > 400 ℃ due to the high activity of Cu-SSZ-13(IWI) catalyst for NH3 oxidation. | Meng-Jie Han Yun-Lei Jiao Chun-Hong Zhou Yang-Long Guo Yun Guo Guan-Zhong Lu Li Wang Wang-Cheng Zhan | 2019 | Rare Metals2019，38，3： | 6 |
| 9 | Metal loaded zeolite adsorbents for hydrogen cyanide removal显示文摘Metal(Cu,Co,or Zn) loaded ZSM-5 and Y zeolite adsorbents were prepared for the adsorption of hydrogen cyanide(HCN) toxic gas.The results showed that the HCN breakthrough capacity was enhanced significantly when zeolites were loaded with Cu.The physical and chemical properties of the adsorbents that influence the HCN adsorption capacity were analyzed.The maximal HCN breakthrough capacities were about the same for both zeolites at 2.2 mol of HCN/mol of Cu.The Cu2p XPS spectra showed that the possible species present were Cu2O and CuO.The N1s XPS data and FT-IR spectra indicated that CNwould be formed in the presence of Cu+/Cu2+ and oxygen gas,and the reaction product could be adsorbed onto Cu/ZSM-5 zeolite more easily than HCN. | Ping Ning Juan Qiu Xueqian Wang Wei Liu Wei Chen | 2013 | Journal of Environmental Sciences2013，25，4： | 6 |
| 10 | A new sorbent that simultaneously sequesters multiple classes ofpollutants from water: Surfactant modified zeolite显示文摘A zeolite (ZFA) was synthesized from coal fly ash and then modified using hexadecyltrimethylammonium. The surfactant modified ZFA (SMZFA) was evaluated for its versatility to sequester multiple classes of pollutants from water. The target pollutants include ionic inorganic pollutants (ammonium and phosphate), ionic organic pollutants (methylene blue and humic acid), ionizable organic pollutants (bisphenol A,-chlorophenol and phenol, with different pKa), and electrically neutral or-ganic pollutants (aniline, nitrobenzene, and naphthalene, with different hydrophobicity). The SMZFA showed high potential for the retention of ammonium and phosphate, being comparable with ZFA. While the negative charge in the internal pores of zeolite was responsible for the retention of ammonium, the oxides of CaO, Al2O3and Fe2O3in the non-zeolite fraction, which originated from coal fly ash but received modification during zeolite synthesis, accounted for the removal of phosphate. Results also showed that while ZFA had little affinity for humic acid, the ionizable, and the electrically neutral organic compounds, SMZFA exhibited greatly enhanced adsorption capacity. Thus, the surfactant modified external surface, which formed a bilayer micelle of zeolite, imparts a hydrophobic characteristic that enables the uptake of the organic pollutants. We showed that SMZFA is a promising versatile sorbent for water treatment. | XIE Qiang XIE Jie CHI LiNa LI ChunJie WU DeYi ZHANG ZhenJia KONG HaiNan | 2013 | Science China(Technological Sciences)2013，56，7： | 5 |
| 11 | High adsorption of Cd(Ⅱ)by modification of synthetic zeolites Y,A and mordenite with thiourea显示文摘Zeolites Y,A and mordenite(ZY,ZA and ZM)were obtained from diatomite in a template-free system,and the products were modified by thiourea(TU).Characterization studies results indicated that the TU molecules were loaded onto the exterior surfaces of the synthetic zeolites as well as the channels.Elemental analysis and energy-dispersive X-ray spectrometer proved that the TU molecules loaded on to ZA were more than ZY and ZM.Removal of Cd(Ⅱ)was investigated,and itwas found that themodified zeolites have higher removal capacity,modified ZA is especially noticeable.In the adsorption experiments,the effects of various parameters such as sorbent content,contact time,concentration of cadmium solution,pH,selectivity and regeneration were discussed.At the best removal efficiency by modified zeolites,the maximum adsorption capacity is 94.3 mg·g^−1,103.2 mg·g^−1 and 89.7 mg·g^−1 at 25℃,respectively.The sorbents show good efficiency for the removal of Cd(Ⅱ)in the presence of different multivalent cations and have good regeneration effect.For the modified samples,removal experiments take place via ion exchange and complexation processes. | Shaoqing Zhang Tianming Lv Yang Mu Jiqi Zheng Changgong Meng | 2020 | Chinese Journal of Chemical Engineering2020，28，12： | 5 |
| 12 | Using ultrasound to improve the sequential post-synthesis modification method for making mesoporous Y zeolites显示文摘Mesoporous Y zeolites were prepared by the sequential chemical dealumination(using chelating agents such as ethylenediaminetetraacetic acid,H EDTA,and citric acid aqueous solutions)and alkaline desilication(using sodium hydroxide,NaOH,aqueous solutions)treatments.Specifically,the ultrasound-assisted alkaline treatment(i.e.,ultrasonic treatment)was proposed as the alternative to conventional alkaline treatments which are performed under hydrothermal conditions.In comparison with the hydrothermal alkaline treatment,the ultrasonic treatment showed the comparatively enhanced efficiency(with the reduced treatment time,i.e.,5 min vs.30 min,all with 0.2 mol·L NaOH at 65°C)in treating the dealuminated Y zeolites for creating mesoporosity.For example,after the treatment of a dealuminated zeolite Y(using 0.1 mol·L H EDTA at 100°C for 6 h),the ultrasonic treatment produced the mesoporous zeolite Y with the specific external surface area()of 160 m·g and mesopore volume()of 0.22 cm·g,being slightly higher than that by the conventional method(i.e.,=128 m·g and=0.19 cm·g).The acidic property and catalytic activity(in catalytic cracking of-octane)of mesoporous Y zeolites obtained by the two methods were comparable.The ultrasonic desilication treatment was found to be generic,also being effective to treat the dealuminated Y zeolites by citric acid.Additionally,the first step of chemical dealumination treatment was crucial to enable the effective creation of mesopores in the parent Y zeolite(with a silicon-to-aluminium ratio,Si/Al=2.6)regardless of the subsequent alkaline desilication treatment(i.e.,ultrasonic or hydrothermal).Therefore,appropriate selection of the condition of the chemical dealumination treatment based on the property of parent zeolites,such as Si/Al ratio and crystallinity,is important for making mesoporous zeolites effectively. | Rongxin Zhang Peinan Zhong Hamidreza Arandivan Yanan Guan Jinmin Liu Na Wang Yilai Jiao Xiaolei Fan | 2020 | Frontiers of Chemical Science and Engineering2020，14，2： | 5 |
| 13 | Optimizing zeolite stabilized Pt-Zn catalysts for propane dehydrogenation显示文摘Propane dehydrogenation(PDH)provides an alternative route to non-petroleum based propylene and eligible catalysts with good overall performance are still being explored.Herein,we report the construction of zeolite stabilized Pt-Zn catalysts Pt-Zn/Si-Beta for PDH.Characterization results from transmission electron microscopy(TEM),ultraviolet-visible(UV-vis)and Fourier transform infrared(FTIR)spectroscopy reveal that highly-dispersed Zn species are stabilized by the silanols from zeolite framework dealumination,which then act as the anchoring sites for Pt species.The close contact between Pt-Zn species and the electronic interaction thereof make Pt-Zn/Si-Beta robust PDH catalysts.Under optimized conditions,a high propylene production rate of 4.11 molmol_(Pt)^(-1)s^(-1),high propylene selectivity of 98% and a sustainable deactivation rate of~0.02 h^(-1)can be simultaneously achieved at 823 K.Coke deposition is not the key reason for the catalytic deactivation,while the loss of Zn species and the resulting aggregation of Pt species under high temperatures are responsible for the irreversible deactivation of Pt-Zn/Si-Beta catalyst in PDH reaction. | Linjun Xie Yuchao Chai Lanlan Sun Weili Dai Guangjun Wu Naijia Guan Landong Li | 2021 | Journal of Energy Chemistry2021，30，6： | 5 |
| 14 | Adsorption Thermodynamics and Diffusion Kinetics of PX over Na Y Zeolite Synthesized by In-Situ Crystallization from Kaolin Microsphere显示文摘Para-xylene was chosen as the probe molecule to study adsorption thermodynamics and diffusion kinetics on NaY zeolite and composite structured NaY zeolite synthesized by in-situ crystallization from kaolin microsphere(designated as Na Y/kaolin composites) separately, using a high precision intelligent gravimetric analyzer(IGA). The adsorption isotherms showed normal Langmuir type-Ⅰ behaviors. The increased adsorption heat with an increasing p-xylene coverage supported a mechanism of phase transition, diffusion and re-arrangement of p-xylene molecules during the adsorption process. The rearrangement seemed to be most pronounced at an adsorption loading of 2.13 and 2.29 mmol/g for Na Y zeolite and Na Y/kaolin composites respectively. Compared with Na Y zeolite, a 2—3 times higher in the diffusion coefficient of p-xylene was observed on Na Y/kaolin composites when the pressure was more than 50 Pa. Temperature-programmed desorption(TPD) of p-xylene on two samples from room temperature to 450 ℃ at a special loading has also been investigated by IGA. Results showed only single desorption peak appeared for Na Y zeolite, indicating that adsorption can only occur in the super-cage structure. Comparably, there were two different peaks for in-situ synthesized Na Y zeolite, corresponding to the two thermo desorption processes in both super-cage structure and the channels provided by kaolin, respectively.Key words: | Zhao Hua Song Lijuan Qin Yucai Duan Linhai Sun Zhaolin | 2014 | China Petroleum Processing & Petrochemical Technology2014，16，4： | 5 |
| 15 | A novel insight into enhanced propane combustion performance on PtUSY catalyst显示文摘Platinum was supported on c-Al_2O_3 and ultrastable Y zeolite(USY) by an incipient wetness impregnation method. The catalysts were characterized by nitrogen physisorption, transmission electron microscopy(TEM),CO/C_3H_8 isothermal oxidations, NH_3 temperature-programmed desorption(NH_3–TPD) and infrared(IR) spectroscopy of adsorbed probe molecules(CO, C_3H_8 and C_3H_8+ O_2). Compared with Pt/Al_2O_3, Pt USY catalyst shows obviously higher activity for the combustion of propane. After estimating the size effect of Pt particles and propane adsorption capacity of USY, the excellent activity of Pt USY is also attributed to the strong interactions between the precious metal and the acidic zeolite. It inhibits the oxidation of Pt in an oxygen-rich atmosphere at high temperatures, which facilitate the initial oxidation step involving the C–H bond activation on metallic Pt as reflected by in situ diffuse reflectance infrared Fouriertransformed(DRIFT) spectra. | Hui Luo Xiao-Dong Wu Duan Weng Shuang Liu Rui Ran | 2017 | Rare Metals2017，36，1： | 5 |
| 16 | Research Progress in Catalytic Cracking Reaction of Tetralin and Decalin显示文摘The integrated catalytic hydrogenation and catalytic cracking process has been gradually adopted by refineries to satisfy the requirements for manufacture of light and clean petroleum products. To explore the reaction laws of hydrogenated aromatics in hydrotreated oil, the catalytic cracking reaction laws of hydrogenated aromatics have been reviewed by taking tetralin and decalin as examples of different degrees of hydrogenated aromatics. Moreover, the reaction mechanism of tetralin and decalin has been analyzed emphatically. The effects of zeolite pore structure, acid properties and process parameters on reaction laws have been analyzed carefully. It is considered that the catalytic cracking performance of hydrogenated aromatics with different hydrogen saturation degrees is quite different. It is necessary to control the hydrogenation depth, optimize the hydrocarbon composition of catalytic cracking feed materials for maximizing the yield of target products. | Li Xiao Xie Chaogang Wei Xiaoli | 2017 | China Petroleum Processing & Petrochemical Technology2017，19，4： | 5 |
| 17 | A comparative study of hydrothermal aging effect on cerium and lanthanum doped Cu/SSZ-13 catalysts for NH_(3)-SCR显示文摘Ce-or La-doped Cu/SSZ-13 catalysts were prepared by a hydrothermal method and Cu,Ce or La ions were incorporated through stepwise ion exchange,The catalyst activity was measured for the ammonia selective catalytic reduction reaction.The structure and composition of catalyst were characterized by using X-ray diffraction,scanning electron microscopy,inductively coupled plasma mass spectrometry solid-state NMR,NH_(3)-TPD techniques,and the active components were examined by XPS and XANES.The results indicate that the Ce and La doping can both completely preserve the SCR activity of Cu/SSZ-13 above 300℃,but there is also a decrease of activity below 200℃.On the other hand,Ce doping is beneficial to the formation of framework aluminum,stabilizes molecular sieve framework and Cu active sites of Cu/SSZ-13,thereby improves the catalyst hydrothermal stability.But La doping will decrease the amount of framework aluminum and Cu active sites of Cu/SSZ-13 after hydrothermally aging,even destroy zeolite CHA structure.This is quite harmful to the catalyst hydrothermal stability. | Di Deng Shujun Deng Dandan He Zhiheng Wang Zhipeng Chen Yi Ji Guoping Yan Guangjin Hou Licheng Liu Hong He | 2021 | Journal of Rare Earths2021，39，8： | 5 |
| 18 | Hydrothermal synthesis of zeolites-calcium silicate hydrate composite from coal fly ash with co-activation of Ca(OH)_(2)-NaOH for aqueous heavy metals removal显示文摘Coal fly ash is a typical secondary aluminum/silicon resource.The preparation of zeolite-type absorbent is a potential way for its value-added utilization,while the purity and adsorption property of zeolite are limited due to the occurrence of side reactions in the synthesis process.In this study,a designated composite consisted of crystalline zeolites and amorphous calcium silicate hydrate was selected,which was direct synthesized from fly ash under conditions of a Ca/Si molar ratio of 0.8,an initial NaOH concentration of 0.5 mol/L,a hydrothermal temperature of 170℃and a liquid–solid ratio of 15 mL/g.The results indicated that this composite had superior adsorption property for a variety of heavy metals,which was based on the exchange of calcium and sodium ions in zeolites and calcium silicate hydrate.Its adsorption capacities for Pb^(2+),Ni^(2+),Cd^(2+),Zn^(2+),Cu^(2+)and Cr^(3+)attained 409.4,222.4,147.5,93.2,101.1 and 157.0 mg/g,respectively,in single solution with a pH of 4.5.After regulating the synthesis conditions,the transformation of amorphous calcium silicate hydrate into crystallized tobermorite weakened the adsorption capacity of the composite.Besides,due to the competitive adsorption in a multiple ions solution,the adsorption capacities for these heavy metals had a reduction. | Guanghui Li Min Li Xin Zhang Pengxu Cao Hao Jiang Jun Luo Tao Jiang | 2022 | International Journal of Mining Science and Technology2022，32，3： | 5 |
| 19 | Engineering Covalent Organic Framework Membranes显示文摘CONSPECTUS:Membrane technology plays an increasingly important role for sustainable development of our society owing to its huge capability to tackle the energy crisis,water scarcity,environmental pollution,and carbon neutrality.To fully unlock the potential of membranes,it is in high demand to develop advanced membrane materials that significantly outperform conventional polymer membrane materials in separation performance and longterm stability.The emergent covalent organic frameworks(COFs)have been deemed as potent membrane materials because of their unique structure and properties in comparison with polymers,zeolites,and metal organic frameworks(MOFs).(i)First,the highly tunable and ordered crystalline pore structure,high porosity,and excellent stability render COFs an ideal membrane material.COFs are more stable than MOFs and,in some cases,are even more stable than zeolite.Moreover,it is easier to introduce functional groups into the COF nanochannels compared with zeolite and MOFs.Further,COFs are ideally suitable for constructing ordered nanochannels with size in the range of 0.6−3 nm which is difficult to be realized by other materials.(ii)Second,along with the unremitting discovery of diverse platform chemistries such as reticular chemistry,the in-depth understanding of nucleation/growth mechanisms of COFs as well as the rapid progress of manufacturing technologies and various routes to fabricating COF membranes with favorable physical and chemical structures inside the nanochannels are being actively exploited.COFs generally show better membrane-formation ability owing to their abundant 2D structures,which make it easier to fabricate ultrathin membranes compared with zeolite and MOFs.(iii)Last,a great number of COF membranes exhibit exceptionally high separation performance and stability,establishing their position as the next-generation membranes.In this Account,we discuss three types of engineering toward COF membranes based on Schiff base reaction for high-efficiency molecules/ion separations,i.e.,reticular engineering,crystal engineering,and nanochannel engineering.First,we discuss the reticular engineering of COF membranes with a focus on the bond types,chemical structure,and architecture design.The membraneformation ability and methods of COFs are also analyzed.Second,we discuss the crystal engineering of COF membranes with a focus on the key thermodynamical and kinetic factors to drive the disorder-to-order transition where we attempt to dig deeper into the crystallization habit of COF membranes.Third,we discuss nanochannel engineering of COF membranes with a focus on the construction and modulation of the physical and chemical microenvironments of nanochannels for efficient and selective transport of molecules/ions.Last,we conclude with a perspective on the opportunities and major challenges in the R&D of COF membranes,targeting at identifying the future directions. | Guangwei He Runnan Zhang Zhongyi Jiang | 2021 | Accounts of Materials Research2021，2，8： | 4 |
| 20 | Recyclable Fenton-like catalyst based on zeolite Y supported ultrafine,highly-dispersed Fe_2O_3 nanoparticles for removal of organics under mild conditions显示文摘A versatile wet impregnation method was employed to conveniently and controllably deposit Fe_2O_3 nanoparticles on zeolites including commercial Y, mordenite and ZSM-5 with the similar framework Si/Al ratios and crystal sizes, respectively. The ultrafine Fe_2O_3 nanoparticles in size of 5 nm can be highly dispersed on zeolite Y matrix due to its much better wettability than ZSM-5 and mordenite. By using the obtained Fe_2O_3/zeolite composite as the heterogeneous Fenton-like catalysts, the degradation of phenol as a model reaction was systematically investigated, including the zeolite supports, particle size and dispersion of Fe_2O_3, and reaction conditions of H_2O_2 concentration, temperature, and pH value. The catalyst based on zeolite Y with Fe loading of 9% exhibited the best phenol degradation efficiency (> 90%)in neutral pH within 2 h. Its high catalytic activity in Fenton reaction can be attributed to the bifunctional properties of strong surface BrФnsted acidity and high reactivity of octahedral Fe^(3+) in the highlydispersed ultrafine Fe_2O_3 nanoparticles in size of 5 nm, which were the primary active centers to quickly decompose H_2O_2 into hydroxyl radicals. Since phenol degradation can be performed under mild conditions of ambient temperature (283-323 K) and a wide pH range (4.0-7.0), the catalysts can be easily recovered for recyclable use with stable degradation activity, which own the immense potential in deep treatment of organic pollutants in industrial wastewater. | Xuanyu Yang Xiaowei Cheng Ahmed A.Elzatahry Jinyang Chen Abdulaziz Alghamdi Yonghui Deng | 2019 | Chinese Chemical Letters2019，30，2： | 4 |
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