CeO2的形貌对CuO/CeO2催化剂CO2加氢制甲醇性能的影响

采用水热法制备CeO₂纳米颗粒（W-CeO₂）、CeO₂纳米片（S-CeO₂）、CeO₂纳米棒（B-CeO₂）及CeO₂纳米八面体（O-CeO₂）,用浸渍法负载相同质量分数的铜形成CuO/CeO₂催化剂。通过扫描电镜（SEM）、高分辨透射电子显微镜（TEM）、X射线衍射（XRD）、拉曼光谱（Raman）、自动吸附分析仪（BET）、H₂程序升温还原（H₂-TPR）、N₂O滴定等表征技术对催化剂进行表征,并在可控温控压的固定床石英管反应器中对催化剂的催化性能进行评价。研究了不同形貌CuO/CeO₂催化剂对CO₂加氢制备甲醇的影响;结果表明,CuO/CeO₂催化剂的催化活性存在明显的形貌依赖性,催化剂的暴露晶面、比表面积、表面碱性位点、表面氧缺陷的差异均会对CO₂转化率、甲醇选择性和产率产生影响。其中,不同形貌CeO₂优先暴露晶面的活性顺序为S-CeO₂（{100}+{110}）>W-CeO₂{100}>B-CeO₂{111}≈O-CeO₂{111},暴露晶面活性越高,催化剂表面氧缺陷越多,CuO-CeO₂间相互作用越强,则催化活性越好。当为CuO/S-CeO₂时,催化剂表面中碱性位点最多,催化剂比表面积为88.8m²/g,铜分散度为19.2%,CO₂转化率为6.56%,甲醇选择性和收率为96.3%和0.063g/(g_cat·h),催化活性最好,由活性评价试验得转化率由高到低依次为S-CeO₂>B-CeO₂>W-CeO₂>O-CeO₂,可知CeO₂形貌差异会决定CuO/CeO₂催化剂的物化性能和催化活性,从而提升对不同形貌CuO/CeO₂催化剂催化CO₂加氢制甲醇的基础认识。     

Iron(III) tetramethoxyphenylporphyrin(FeTMPP) as methanol tolerant electrocatalyst for oxygen reduction in direct methanol fuel cells

Carbon supported iron (III) tetramethoxyphenylporphyrin (FeTMPP) heat treated at 800°C under argon atmosphere was used as catalysts for the electroreduction of oxygen in direct methanol polybenzimidazole (PBI) polymer electrolyte fuel cells that were operated at 150°C. The electrode structure was optimized in terms of the composition of PTFE, polymer electrolyte and carbon-supported FeTMPP catalyst loading. The effect of methanol permeation from anode to cathode on performance of the FeTMPP electrodes was examined using spectroscopic techniques, such as on line mass spectroscopy (MS), on line Fourier transform infrared (FTIR) spectroscopy and conventional polarization curve measurements under fuel cell operating condition. The results show that carbon supported FeTMPP heat treated at 800°C is methanol tolerant and active catalyst for the oxygen reduction in a direct methanol PBI fuel cell. The best cathode performance under optimal condition corresponded to a potent ial reached of 0.6V vs RHE at a current density of 900 mAcm–2.     

Poly(vinyl alcohol)/Cu(II) complex anion exchange membranes prepared using chemical fiber for direct methanol fuel cells

PVA/Cu (II) complex anion exchange membranes (AEMs) were prepared for direct methanol fuel cells. The complex was for the first time used as membrane material of AEMs. Glutaraldehyde as a crosslinking agent was introduced to control water uptake and swelling of the membranes. The membranes with thickness of 1 μm were fabricated using chemical fibers based on the solution surface tension. The complex membranes show good ionic conductivity and low methanol permeability in the magnitude of 10^?2 S · cm^?1 and 10^?7 cm^?2 · S^?1, respectively. This is a facile, efficient, green, and fast way to prepare new AEMs for direct methanol fuel cells. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 130: 1172‐1178, 2013     

Iron(III) tetramethoxyphenylporphyrin (FeTMPP-C1) as electrocatalyst for oxygen reduction in direct methanol fuel cells

Iron(III) tetramethoxyphenylporphyrins (FeTMPP-C1) adsorbed on high-area carbons were heat treated in an inert atmosphere at various temperatures ranging from 200–1000 °C to produce catalyst for the electroreduction of oxygen in acid electrolytes. It was found that the specific surface area of the FeTMPP-C1/C catalysts linearly decreases with increase of the FeTMPP-C1 loading on RB carbon. The electrical resistivity of the catalyst decreases with the increase of heat treatment temperature in the range of 200 to 800 °C, then it increases beyond 800 °C. The results obtained with elemental analysis, FTIR spectroscopy and XPS techniques indicate that the onset temperature for partial decomposition for the FeTMPP chelate occurs at temperatures of about 400–500 °C. The surface concentrations of both iron and nitrogen on the carbon support increase as the heat treatment temperature increases, and the maximum occurs at 700 °C. Some possibilities about the nature of active sites in the catalyst are discussed.     

高效可见光响应微生物/光电化学耦合人工光合作用系统

人工光合作用系统可以利用太阳能将二氧化碳转化为高附加值的化学产品,能够有效地解决人类面临的能源与环境问题,极具发展前景。然而,人工光合作用系统面临产物选择性差、过电位高、太阳能利用率低等重大挑战。本文提出了一种新型微生物/光电化学耦合人工光合作用系统,该系统由固碳产甲烷微生物阴极和复合光阳极组成,其中复合光阳极由TiO₂电极与硅太阳能电池串联组成。该耦合系统在仅输入太阳能且不施加外部偏压的条件下,可实现化学燃料甲烷的产生。甲烷产量高达（10.7±0.2） L·d^-1·m^-2,相比已有研究高出13倍,同时该耦合系统固碳产甲烷的法拉第效率高达98.5%±2.1%,远高于传统的人工光合作用系统。该新型人工光合作用系统的提出,为制取具有高附加值的化学产品和发展可再生能源提供了新的思路。     

Cu2O/TiO2 heterostructure nanotube arrays prepared by an electrodeposition method exhibiting enhanced photocatalytic activity for CO2 reduction to methanol

Cu₂O/TiO₂ composite nanotube arrays demonstrating enhanced photocatalytic performance were synthesized using an electrodeposition method to impregnate the p-type Cu₂O into the n-type titanium dioxide nanotube arrays (TNTs). The morphological results confirmed that the TNTs are wrapped by the Cu₂O nanoparticles and the UV–Vis absorption spectra showed that the Cu₂O/TNTs display a better ability for visible light absorption compared to the pure TNTs. CO₂ photocatalytic reduction experiments carried out by using Cu₂O/TNT nanocomposites proved that Cu₂O/TNTs exhibit high photocatalytic activity in conversion of CO₂ to methanol, while pure TNT arrays were almost inactive. Furthermore, Cu₂O/TNTs also exhibited augmented activity in degradation of target organic pollutant like acid orange (AO) under visible light irradiation. The ultra enhanced photocatalytic activity noticed by using Cu₂O/TNTs in CO₂ reduction and degradation of organic pollutant could be attributed to the formation of Cu₂O/TiO₂ heterostructures with higher charge separation efficiency.     

Photocatalytic activity of Cu2O supported on multi layers graphene for CO2 reduction by water under batch and continuous flow

The photocatalytic activity of Cu₂O supported on multi-layers graphene for CO₂ reduction by water was studied under two hydrodynamic environments, in a slurry batch reactor and in a capillary reactor with the catalyst immobilized on the wall. Under both conditions, the major photoproduct was hydrogen observed in the gas phase, accompanied by lesser amounts of ethanol present in the aqueous solution. The maximum production rates were 2031 and 545 μmol g^− 1 h^− 1 for H₂ and CH₃CH₂OH, respectively, and were found under the hydrodynamic mode attained in the capillary reactor.     

Si掺杂对Cu/ZrO2催化CO2加氢制甲醇性能的影响

为了提高Cu/ZrO₂催化剂在二氧化碳加氢制甲醇中的催化活性,制备了一系列不同Si/Zr的Si-ZrO₂载体并负载5%（质量分数）Cu得到了Cu/Si-ZrO₂催化剂。对所制备的催化剂进行了X射线衍射（XRD）、N₂物理吸脱附（BET）、X射线光电子能谱（XPS）、氢气程序升温还原（H₂-TPR）、二氧化碳程序升温脱附（CO₂-TPD）及高分辨透射电子显微镜 （HRTEM） 的表征。结果表明,Si的掺杂使得Cu/ZrO₂体系获得了稳定的晶相,大的比表面积和更多的碱性位点,尤其是中强碱性位点,同时产生了更多的氧空位,促进了CO₂的吸附和转化,因此得到了更高活性的催化剂。当Si与Zr的摩尔比为0.2时,在质量空速为6000 ml·g^-1·h^-1,温度为220℃、压力为3.0 MPa,V（H₂）∶V（CO₂）=3∶1（体积比）条件下,催化剂的CO₂转化率为4.6%,CH₃OH选择性为85%。     

Si掺杂对Cu/ZrO2催化CO2加氢制甲醇性能的影响

为了提高Cu/ZrO₂催化剂在二氧化碳加氢制甲醇中的催化活性,制备了一系列不同Si/Zr的Si-ZrO₂载体并负载5%（质量分数）Cu得到了Cu/Si-ZrO₂催化剂。对所制备的催化剂进行了X射线衍射（XRD）、N₂物理吸脱附（BET）、X射线光电子能谱（XPS）、氢气程序升温还原（H₂-TPR）、二氧化碳程序升温脱附（CO₂-TPD）及高分辨透射电子显微镜 （HRTEM） 的表征。结果表明,Si的掺杂使得Cu/ZrO₂体系获得了稳定的晶相,大的比表面积和更多的碱性位点,尤其是中强碱性位点,同时产生了更多的氧空位,促进了CO₂的吸附和转化,因此得到了更高活性的催化剂。当Si与Zr的摩尔比为0.2时,在质量空速为6000 ml·g^-1·h^-1,温度为220℃、压力为3.0 MPa,V（H₂）∶V（CO₂）=3∶1（体积比）条件下,催化剂的CO₂转化率为4.6%,CH₃OH选择性为85%。     

Strongly visible-light responsive plasmonic shaped AgX:Ag (X = Cl, Br) nanoparticles for reduction of CO(2) to methanol

Plasmonic shaped AgX:Ag (X = Cl, Br) nanoparticles have been synthesized by a facile and versatile glycerol-mediated solution route. The as-prepared AgX:Ag nanoparticles exhibit regular shapes, i.e., cube-tetrapod-like AgCl:Ag nanoparticles and AgBr:Ag nanoplates. Compared with the pristine AgX, AgX:Ag nanocomposites display stronger absorption in the visible region due to the surface plasmon resonance of silver nanoparticles. The calculation of bandgaps and band positions indicates the as-achieved AgX:Ag nanoparticles can be used as a class of potential photocatalyst for the reduction of CO(2). For example, reduction of CO(2) under visible light irradiation with the assistance of the anisotropic AgX:Ag nanoparticles yields as much as 100 μmol methanol in the products. Furthermore, the AgX:Ag nanoparticles can maintain its structure and activity after 3 runs of reactions. Therefore, the present route opens an avenue to acquire plasmonic photocatalysts for conversion of CO(2) into useful organic compounds.     

Sulfonated poly(arylene ether sulfone) membranes based on biphenol for direct methanol fuel cells

A series of sulfonated poly(arylene ether sulfone) (PAES) were synthesized through direct aromatic nucleophilic substitution polycondensation of 3,3′-disulfonate-4,4′-dichlorodiphenylsulfone (SDCDPS), 4,4-dichlorodiphenylsulfone (DCDPS) and 4,4-biphenol (BP). With increasing sulfonate groups in the polymer, water uptake, ion exchange capacity (IEC) and proton conductivities increased, resulting from enhanced membrane hydrophilicity. The membranes exhibited higher thermal stability up to 300 °C, verified by thermogravimetric analysis (TGA). A maximum proton conductivity of 0.11 S/cm at 50 mol% of sulfonation degree was measured at 30 °C, which is slightly higher than Nafion®117 membrane (0.0908 S/cm). However, the methanol permeability of the PAES membrane was much lower than that of Nafion®117 membrane. As a result, a single cell performance test demonstrated that PAES-BP with 50 mol% sulfonation degree exhibited higher power density than Nafion®117.     

Improving electrochemical performance of (Cu,Sm)CeO2 anode with anchored Cu nanoparticles for direct utilization of natural gas in solid oxide fuel cells

Development of solid oxide fuel cell (SOFC) anode with high resistance to coking and sulfur poisoning is highly desirable for the direct application of natural gas in SOFC. Herein, a (Cu, Sm)CeO₂ anode with anchored Cu nanoparticles has been prepared. Most of Cu nanoparticles particle size ranges from 20 to 50 nm, which can increase the conductivity and catalytic activity of the anode. The Cu/CSCO10 supported cell exhibits a maximum power density of 404.6 mW/cm² at 600 °C when dry methane is used as fuel while its ohmic resistance is only 0.39 Ω cm². The single SOFC shows good stability when H₂S content in the fuel is less than 150 ppm. Up to 900 h of continuous stable operation with simulated natural gas and commercial natural gas as fuel prove the advantages and application potential of this anode.     

Self-assembly of thiourea intercalated graphene oxide based dual IIP for the SPE coupled FAAS method development of Cu(II) and Pb(II) determination

A new dual-template surface imprinted polymer for Cu(II) and Pb(II) was synthesized in one pot. Magnetic graphene oxide was self-assembled with low cost and environmentally benign thiourea. Presence of sulfur and nitrogen donor atoms provide hooks for coordination and partial reduction of graphene oxide matrix. It was used as an solid-phase extraction adsorbent for extraction, preconcentration, and coupled with flame atomic absorption spectrometry to manifest performance comparable with inductively coupled plasma atomic emission spectrometry (ICPAES) both in terms of quantification limit as well as interference. The critical experimental parameters such as pH; 4.6, contact time of 15 min and initial concentration of 777 (Q_e; 227 mg g⁻¹) and 800 μg L⁻¹ (Q_e; 273 mg g⁻¹) for Cu(II) and Pb(II), respectively, were optimized using RSM-CCD and artificial neural network. The adsorption process was kinetically faster (50% adsorption in 5 min), following fractal-like-pseudo-second-order (FLPSO) kinetics and Brouers–Sotolongo isotherm model owing to the heterogenous energy landscape. The imprinting factors were in the range of 4–7 in the presence of all coexisting ions. The proposed method was robust in the determination and removal of Cu(II) and Pb(II) from food, ground water, and industry effluents with low limit of detection (Cu(II); 1.03 μg L⁻¹ & Pb(II); 1.79 μgL⁻¹). Spiking and recovery tests were used to assess the method's accuracy. Cu(II)/Pb(II) loaded dual template IIP (DIIP) was utilized to remove anionic dyes with >95% efficiency. Thorough examination of the method and material selectivity (in binary, ternary, and multielement system), multi fold applications of determination, removal of Cu(II), Pb(II), and removal of anionic dyes makes DIIP a promising candidate for environmental remediation.     

Annulated dinuclear palladium(II) phthalocyanine complex as an effective photo-oxidation catalyst for near-infrared region light

An annulated dinuclear palladium(II) phthalocyanine complex (1) was synthesized and characterized. It was found that 1 worked as a photo-catalyst for the decomposition of 1,3-diphenylisobenzofuran (DPBF) in aerated toluene under the irradiation of the light in the near-infrared (NIR) region (λ > 780 nm).     

Electrocatalysis for the reduction of O2 and H2O2 based on complex of copper(II) with the tris(3-aminopropyl)amine and imidazole ligands

The Cu(II) complex of [tris(3-aminopropyl)][imidazole]Cu(II)perchlorate was synthesized. This complex can adsorb on a pyrolytic graphite electrode surface where it functions as an electrocatalyst for the reduction of O2 and H2O2. The electrocatalytic kinetics of both substrate reductions were studied by cyclic voltammetric and rotating disc electrode methods. The catalyst accomplishes the four-electron reduction of O2 to H2O at a significantly greater rate than it catalyses the two-electron reduction of H2O2, so that the latter cannot be an intermediate in the reduction of O2.     

Anion exchange membranes based on poly(vinyl alcohol) and quaternized polyethyleneimine for direct methanol fuel cells

The semi‐interpenetrating polymer network technique was applied in the preparation of anion exchange membranes for direct methanol fuel cells (DMFCs). Poly(vinyl alcohol) was chosen as the polymer matrix and quaternized polyethyleneimine was used as the cationic polyelectrolyte. To modify the polymer membranes for achieving desirable properties, 1,2‐bis(triethoxysilyl) ethane was used as a precursor to fabricate a set of organic–inorganic hybrid membranes. The hybrid membranes were characterized using X‐ray diffraction, scanning electron microscopy, and thermogravimetric analysis. The ionic conductivity, methanol permeability and stability under oxidative and alkaline conditions were measured to evaluate the applicability in DMFCs. © 2012 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013     

The NHR2/CO2 system as a metal ion extraction reagent from aqueous solution into hydrocarbons: copper(II) and zinc(II)

A substantially quantitative transfer of copper(II) or zinc(II) salts from aqueous solution into a hydrocarbon (heptane or toluene) promptly occurs under carbon dioxide in the presence of a dialkylamine (NHR₂, R = Bu, Bz). Recovery of the metal complexes from the organic phase affords copper dialkylcarbamates of the formula Cu(O₂CNR₂)₂(NHR₂)₂ or μ-oxo tetranuclear zinc carbamato complexes, Zn₄(μ₄-O)(O₂CNR₂)₆, respectively, in high yield and purity. An X-ray diffraction study on a single crystal of Cu(O₂CNBz₂)₂(NHBz₂)₂ 1 has shown the compound to be mononuclear with tetracoordinated copper in an almost perfect square-planar geometry. The zinc derivative has the well-established oxo-centred tetranuclear structure (R = Bu, 2).     

Saccharide derived dinuclear Cu(II) complex: An efficient catalyst for oxidation of catechol and benzylic alcohols

Catalytical aspect of 4,6-O-ethylidene-β-D-glucopyranosylamine derived dinuclear Cu(II) complex has been explored. The complex exhibits good catecholase like activity and oxidizes model substrate 3,5-di-tert-butylcatechol to 3,5-di-tert-butyl-o-quinone. The complex also acts as selective catalyst to oxidize the primary and secondary alcohols to corresponding carbonyl compounds in excellent yield (65–82%) under mild conditions.     

A new selective fluorescent chemosensor for Cu(II) ion based on zinc porphyrin-dipyridylamino

A new fluorescent chemosensor 5-(p-N,N′-bis(2-pyridyl)amino)phenyl-10,15,20-tris(p-methoxyphenyl)porphyrin zinc has been designed and synthesized by the Ullmann-type coupling. It displays high selectivity for Cu²⁺ ion and exhibits fluorescence quenching upon binding of Cu²⁺ ion with an “on–off” type fluoroionophoric switching property, and its fluorescence can be revived by addition of EDTA disodium solution.