Increasing Volumetric CO2 Uptake of Hypercrosslinked Polymers through Composite Formation

To overcome the drawbacks of solid microporous materials for CO₂ capture, this proof‐of‐concept study demonstrates a low‐cost and rapid method for producing composites consisting of hypercrosslinked polymers (HCP) with a polyethyleneimine (PEI) binder. The resulting materials capture CO₂ through physical and chemical absorption simultaneously. Compared with HCP, the composites exhibit higher CO₂ uptake, higher volumetric density, and improved tolerance to water which is attributed to the PEI binder.     

Hypercrosslinked polymers incorporated with imidazolium salts for enhancing CO2 capture

Hypercrosslinked polymers (ILHCPs) incorporated with imidazolium salts were prepared using 4‐vinylbenzyl chloride, divinylbenzene, and imidazole ionic liquid monomers with various alkyl groups and anions by free radical copolymerization and Friedel‐Crafts alkylation reaction. The structures of ILHCPs were characterized by using FT‐IR, solid state ¹³C CP/MAS NMR spectroscopy, TGA, and gas adsorption. ILHCPs exhibit excellent capability of CO₂ adsorption compared with that of nonfunctional hypercrosslinked polymers (HCPs), although both the BET surface area (447–667 m²/g) and pore volume (0.24–0.28 cm³/g) of ILHCPs are less than HCPs. The synergistic effect from mirco/mesopore structures and imidazolium salts are proved to play a key role in enhancing the CO₂ adsorption capability and selectivity over other gases for ILHCPs. It can be found that the imidazolium salts content in HCPs is more important compared with the pore texture for adsorbing CO₂. An optimal molar content of imidazolium salts groups is found to be 10.5% with the maximum CO₂ uptake capability of 7.56 wt% and best CO₂ adsorption selectivity (CO₂/N₂) of 47.9/1 (273 K, 1 bar), while those of the HCPs are only 5.93 wt% and 27.9/1. Such results strongly suggest that ILHCPs can be promising applied in selective CO₂ separation. POLYM. ENG. SCI., 56:573–582, 2016. © 2016 Society of Plastics Engineers     

Facile Synthesis of Activated Carbon-Supported Porous Manganese Oxide via in situ Reduction of Permanganate for Ozone Decomposition

Lichen-like porous manganese oxides (MnO_x) with birnessite-type structure, which were assembled with curled nanosheets (less than 10 nm in thickness), were deposited in situ on the surface of activated carbon (AC) via facile reduction of permanganate by AC, and were tested for the decomposition of ozone, a common air pollutant. Despite the low Mn loading (typically 0.04%–0.14%), the as-synthesized MnO_x/AC catalysts exhibited high catalytic activity and stability for ozone decomposition at room temperature and high relative humidity, which can be attributed to the enrichment of the Mn element on the catalyst surface and a well-organized porous surface morphology of MnO_x.     

聚苯胺基多孔炭制备及 CO 捕集性能研究

以聚苯胺为原料,采用NaOH活化法,在原料与活化剂质量比为1砄4的情况下,研究了不同的活化时间（0.5 h、1 h、2 h）对多孔炭孔隙结构和CO2吸附性能的影响。通过N2吸附脱附、扫描电子显微镜（SEM）、透射电子显微镜（TEM）,对样品的孔隙结构和形貌进行了表征。采用变压吸附法在常温常压下测试了样品对CO2的吸附性能。结果表明：当活化时间为1 h时,比表面积达到最大值2024 m2／g,微孔孔容达到最大值0.926 cm3／g。然而,当活化时间为0.5 h时, CO2吸附量达到了最大值159 mg／g,表明了CO2吸附量与窄微孔孔径分布有直接关系。     

Photocatalytic Reduction of CO2 with H2O on Ti-Containing Porous Silica Thin Film Photocatalysts

Two different Ti-containing porous silica thin films having a hexagonal and cubic pore structure were synthesized and used as photocatalysts for the reduction of CO₂ with H₂O at 323 K. UV irradiation of the Ti-containing porous silica thin films in the presence of CO₂ and H₂O led to the formation of CH₄ and CH₃OH with a high quantum yield of 0.28%. These porous silica thin film photocatalysts having a hexagonal pore structure exhibited higher reactivity than the Ti-MCM-41 powder photocatalysts with the same pore structure.     

高温合成结晶多孔氧化钴及其催化苯的燃烧

通过高温水热技术制备高度晶化的多孔氧化钴并研究其在催化苯类VOCs消除中的应用。多孔结构的形成通过硝酸钴与聚四乙烯基吡啶酸碱对自组装实现,经过高温水热处理(180℃)完成孔壁晶化。XRD测试表面该材料具有高度晶化的孔壁结构。电子显微镜技术测试发现制备的氧化钴材料具有丰富的表面纳米多孔结构。催化性能测试发现该材料在温和的条件下即可以实现苯类VOCs的完全催化氧化,该材料将在催化氧化VOCs具有重要的应用价值。     

Porous MoxCy/SiO2 Material for CO2 Hydrogenation

The synthesis and characterization of an inexpensive porous Mo_xC_y/SiO₂ material is presented, which was obtained by mixing ammonium hexamolybdate, sucrose, and a mesoporous silica (SBA-15), with a subsequent heat treatment under inert atmosphere. This porous material presented a specific surface area of 170 m²/g. The catalytic behavior in CO₂ hydrogenation was compared with that of Mo₂C and α-MoC_1?x obtained from ammonium hexamolybdate and sucrose, using different Mo/C ratios. CO₂ hydrogenation tests were performed at moderate (100 kPa) and high pressures (2.0 MPa), and it was found that only CO, H₂O and CH₄ are formed at moderate pressures by the three materials, while at higher pressures, methanol and hydrocarbons (C₂H₆, C₃H₈) are also obtained. Differences in selectivity were observed at the high pressure tests. Mo₂C presented higher selectivity to CO and methanol compared with MoC_1?x, which showed preferential selectivity to hydrocarbons (CH₄, C₂H₆). The porous Mo_xC_y/SiO₂ material showed the highest CO₂ hydrogenation activity at high temperatures (270 and 300 °C), being a promising material for the conversion of CO₂ to CO and CH₄.

     

4-丙硫基-2-硝基苯胺CO选择还原合成-4-丙硫基邻苯二胺

首次将Ru3(CO)9(TPP)3配合物催化剂用于4 丙硫基 2 硝基苯胺(Ⅰ)的CO选择还原反应,考察了反应条件对反应转化率和选择性的影响。PCO=5 0MPa,θ=140℃,t=20h,n(Ⅰ)/n(Ru)=300的反应条件下,转化率为83%,选择性达98%,为合成高效广谱驱虫药阿苯达唑(Albendazole)关键中间物4 丙硫基邻苯二胺提供了一条环境友好新路线。     

卧式CO_2压缩机减振技术

介绍了二氧化碳回收装置二氧化碳压缩机组,在运行过程中出现振动引起一系列问题及采取的减振技术措施。该技术解决了振动问题,使得压缩机组维护频次及开、停压缩机频次减少。     

Application of Optical-fiber Photoreactor for CO2 Photocatalytic Reduction

An optical-fiber photoreactor, comprised of 216 catalyst-coated fibers, was designed and assembled to transmit and spread light uniformly inside the reactor. The power loss of light transmission inside an optical fiber was calculated using beam propagation method. The optimum length of optical fiber was estimated to be near 11 cm long in order to entirely spread out light energy over surface catalyst. Vapor-phase CO₂ was photocatalytically reduced to methanol using the photoreactor under UV irradiation in a steady-state flow system. The solutions of metal-loaded titania were prepared by thermal hydrolysis method. Metal-loaded TiO₂ film was coated on optical fibers by dip-coating method. TiO₂, Cu/TiO₂ and Ag/TiO₂ films were uniformly on the fibers and their thicknesses ranged from 27 to 33 nm. The films consisted of very fine spherical particles with diameters of 10–20 nm. The XRD spectra indicated anatase phase for all films. Methanol yield increased with UV irradiative intensity. Maximum methanol rate was 4.12 μmole/g-cat h using 1.0 wt%-Ag/TiO₂ catalyst at 1.13 bar of CO₂, 0.03 bar of H₂O pressures, and 5,000 s mean residence time under 10 W/cm² UV irradiation.     

金属有机骨架在电催化还原CO2中的应用

金属有机骨架是一种复合材料,其具有高比表面积、单位质量体积小、官能团结构能够调节的性质.这些特性使金属有机骨架在电催化还原二氧化碳领域有广泛的应用前景.本文介绍了单金属基有机骨架和多金属基有机骨架在电催化还原CO2领域的应用,最后讨论了金属有机骨架材料面临的局限性.     

Synthesis of a Porous Nano‐CaO/MgO‐Based CO2 Adsorbent

A porous nano‐CaO/MgO‐based adsorbent was prepared using MgO as a support in order to increase the sorption capacity and durability. The magnesium sol prepared by reacting MgO slurry with citric acid was added to nano‐CaCO₃ slurry and the mixture was calcinated to obtain the nano‐CaO/MgO‐based adsorbent. The influence of MgO content on the structure and sorption performance of the resulting adsorbent was studied in detail. The pore radius and specific surface area of the adsorbent increased with higher MgO content. The adsorbent exhibited superior sorption performance during calcium looping and maintained a good durability at the calcination temperature, thus being an interesting candidate for future work.     

Design of Functionalized Room-Temperature Ionic Liquid-Based Materials for CO2 Separations and Selective Blocking of Hazardous Chemical Vapors

The design and synthesis of several new types of functionalized room-temperature ionic liquids (RTILs), ionic polymers based on RTILs (i.e., poly(RTIL)s), poly(RTIL)-RTIL solid-liquid composites, and gelled RTIL systems for gas separations and reactive vapor transport applications are presented. The design concepts behind these new RTIL materials are discussed in the context of first, CO₂ removal from CH₄ and N₂ for natural gas purification and greenhouse gas reduction, respectively; and second selective blocking or sorption of chemical warfare agent simulant and toxic industrial compound vapors from water vapor for protection applications. The role of the RTIL components and their unique properties in these two separations areas will be highlighted.     

Separation of N2O and CO2 using Room-Temperature Ionic Liquid [bmim][Ac]

We have developed a ternary equation of state (EOS) model for the N₂O/CO₂/1-butyl-3-methylimidazolium acetate ([bmim][Ac]) system in order to understand the separation of N₂O and CO₂ using room-temperature ionic liquids (RTILs). The present model is based on a generic RK (Redlich-Kwong) EOS, with empirical interaction parameters for each binary system. The interaction parameters have been determined using our measured VLE (vapor-liquid-equilibrium) data for N₂O/[bmim][Ac] and literature data for CO₂/[bmim][Ac] and N₂O/CO₂. The binary EOS model for the N₂O/[bmim][Ac] system correctly predicted the liquid-liquid phase separation found in VLLE experiments. The validity of the ternary EOS model has been checked by conducting VLE experiments for the N₂O/CO₂/[bmim][Ac] system over a temperature range from 296 to 313 K. With this EOS model, solubility (VLE) behavior has been calculated for various (T, P, and feed compositions) conditions. Over a range of N₂O/CO₂ feed ratios, the N₂O/CO₂ gas selectivity [α _{N 2 O/CO 2}  = (y _{N 2 O} /x _{N 2 O} )/(y _{CO 2} /x _{CO 2} )] increases by at least 5 orders of magnitude when adding [bmim][Ac] (α = 1 × 10² to 1 × 10⁷), compared with the absence of the ionic liquid (α = 0.96 to 0.98). The addition of [bmim][Ac] may provide a practical means of separating CO₂ and N₂O.

Supplemental materials are available for this article. Go to the publisher's online edition of Separation Science and Technology to view the free supplemental file.     

Photo-Electrochemical Reduction of CO2 to Methanol on Quaternary Chalcogenide Loaded Graphene-TiO2 Ternary Nanocomposite Fabricated via Pechini Method

Journal of Inorganic and Organometallic Polymers and Materials - Nano-sized catalysts have been widely studied for CO2 reduction to hydrocarbon fuels. Herein, we study the new-modeled ternary...     

荔枝核淀粉接枝丙烯酸合成高吸水树脂

采用静态水溶液聚合法成功制备了一种水凝胶型荔枝核淀粉接枝丙烯酸高吸水树脂(SAP)。研究发现,乙二胺四乙酸二钠(EDTA)的加入不仅显著提高淀粉/高岭土复合吸水性树脂的产率,而且使其吸水性得到提高。详细研究了不同反应条件对产物吸水性和产率的影响,获得了复合吸水性树脂的最佳合成工艺,在最优条件下合成的树脂吸收自来水、纯水、生理盐水和人工尿液的倍率分别为(764±21)、(3 152±26)、(128±2)、(110±1)g/g。分别利用傅里叶变换红外光谱仪(FTIR)、热重分析仪、扫描电镜、能谱和碘染色等对复合吸水性树脂进行定性分析,结果表明:丙烯酸成功接枝到淀粉分子链上,同时保留了部分淀粉的分子链结构;高岭土成功与淀粉基高吸水树脂复合,产物热稳定性有所提高。     

Synthesis of Novel Polyamide-Hyperbranched Polymers via Self Condensing Atom Transfer Radical Polymerization

Novel inimer was synthesized from p-amino phenol via successive preparative methods by using both bromoisobutyrylbromide and acryloyl chloride. The new inimer was well characterized via Infrared Spectra (IR) and ¹ Fréchet , J.M.J. ; Tomalia , D.A. , Ed. Dendrimers and Other Dendritic Polymers , Wiley : West Sussex , 2001 .[Crossref] , [Google Scholar]H nuclear magnetic resonance (NMR). New hyperbranched polyamide (H₁) was prepared via Atom Transfer Radical Polymerization (ATRP). Several reaction conditions (ligands, solvents, temperatures, etc.) were studied. However, the N,N,N′,N″,-pentamethyldiethylenetriamine (PMDETA)/CuBr catalytic system showed good results in toluene at 100°C. Three arm star methylmethacrylate (MMA) homopolymers reacted with (H₁) in different percentages to form copolymers with low polydispersity values, especially at 1:115 for poly MMA:H₁. The formed polymers were characterized via Gel Permeation Chromatography (GPC), ¹ Fréchet , J.M.J. ; Tomalia , D.A. , Ed. Dendrimers and Other Dendritic Polymers , Wiley : West Sussex , 2001 .[Crossref] , [Google Scholar]HNMR, thermal analyses, and Transmission Electron Microscopy (TEM).     

基于半经验模型的CO_2在聚合物中的溶解度计算

为了评价CO2在聚合物中溶解度计算的5种半经验模型,通过计算CO2在10种聚合物中溶解度的误差平均值和标准差,比较了各个模型的性能。结果表明:预测效果的主要影响因素是模型方程式复杂程度及方程式的变量。从预测结果看,A-L模型优于Chrastil模型及其修正的密度型模型;5种模型中,Gordillo模型的预测精度及预测稳定性较好。     

Synthesis and Characterization of SnO2 on Porous Silicon for Photoconversion

Silicon - A photoconversion device was fabricated based on SnO2 film prepared by a chemical spray pyrolysis technique. The SnO2 nanofilms were grown on the porous silicon (PS) nanosurface. Various...