Highly efficient and selective photocatalytic dehydrogenation of benzyl alcohol for simultaneous hydrogen and benzaldehyde production over Ni-decorated Zn_(0.5)Cd_(0.5)S solid solution

Photocatalytic conversion of solar energy into hydrogen and high value-added fine chemicals has attracted increasing attention. Herein, we demonstrate an efficient photocatalytic system for simultaneous hydrogen evolution and benzaldehyde production by dehydrogenation of benzyl alcohol over Nidecorated Zn_(0.5)Cd_(0.5)S solid solution under visible light. The photocatalytic system shows an excellent hydrogen production rate of 666.3 μmol h^(-1) with high stability. The optimal apparent quantum yield of52.5% is obtained at 420 nm. This noble-metal-free photocatalytic system displays much higher activity than pure Zn_(0.5)Cd_(0.5)S and Pt-loaded Zn_(0.5)Cd_(0.5)S solid solution. Further studies reveal that the metallic Ni nanocrystals play an important role in accelerating the separation of photogenerated charge carriers and the subsequent cleavage of α-C–H bond during dehydrogenation of benzyl alcohol.

The Hydrogen Energy Potential of Solid Waste: A Case Study of Misrata City

This study presents an overview on solid waste that can be used as a source of bioenergy in Misrata including municipal solid waste (MSW), industrial solid waste (ISW), and healthcare solid waste (HSW) as biomass sources. The management of solid waste and valorization is based on an understanding of MSW’s and HSW’s composition and physicochemical characteristics. Of MSW’s, the results show that organic matter represents 59% of waste, followed by paper-cardboard 12%, miscellaneous 10%, plastic 8%, metals 7% and glass 4%. While HSW comprised of 72% general healthcare waste (non-risk) and 28% hazardous waste. The average general waste composition was: 38% organic, 24% plastics, and 20% paper. The potential of hydrogen energy produced from biogas in Misrata including MSW, and other organic feedstock such as food and kitchen waste, animal wastes, clover and reeds, wheat residues, barley residues, HSW and sewage waste as biomass sources. The total potential hydrogen output is estimated to be around 10,265 tons per year.

Recovery of valuable metals from anode material of hydrogen-nickel battery

Simultaneous recovery of rare earth,nickel and cobalt resources from the anode material of hydrogen-nickel battery was performed through a hydrometallurgical process. Most of rare earth elements are separated from nickel and cobalt in the form of sulfates when the anode material is firstly leached with sulfuric acid. Then,the precipitated rare earth sulfates are dissolved with sodium hydroxide to form rare earth hydroxides. The rare earth element,zinc and manganese ions in the lixivium are also separated from nickel and cobalt by using PC-88A extractant system,and the organic phase loaded rare earth is stripped with hydrochloric acid. By neutralizing the stripping solution with rare earth hydroxide,the rare earth chloride is obtained. Under the suitable leaching conditions of sulfuric acid 3 mol/L,leaching time 4 h and temperature 95 ℃,94.5% of rare earth in the anode material is transformed into the sulfate precipitates,and the leaching ratios of nickel and cobalt can approach 99.5%. When the pH value of the extractive system is controlled in the range of 3.0-3.5,the rare earth elements in the lixivium can be extracted completely into the organic phase,and the stripping recovery of the rare earth can reach 98% in the extraction stage. The total recoveries of rare earth,nickel and cobalt are 98.9%,98.4% and 98.5%,respectively.

Improved hydrogen storage properties of MgH_2 catalyzed with K_2NiF_6

In this study, the hydrogen storage properties of MgH-X wt% KNiF（X = 5, 10, 15, 20, and 50） were investigated for the first time. From the analysis of the onset desorption temperature and isothermal de/absorption kinetics, it was shown that MgH+ 5 wt% KNiFsample has the best performance. The 5wt% doped sample started to release hydrogen at about 260 °C, which was a reduction of about 95 °C and 157 oC compared with the as-milled and as-received MgH. In addition, the de/absorption kinetics of the MgH+ 5 wt% KNiFwere also improved significantly compared to the un-doped MgH. The apparent activation energy for hydrogen desorption exhibited the decrement from 167.0 k J/mol for as-milled MgHto 111.0 k J/mol with the addition of 5 wt% KNiF. Moreover, the X-ray diffraction spectra displayed the formation of new phases of KF, KH, MgNi and MgNiHby doping the KNiFwith MgHafter the dehydrogenation and rehydrogenation processes. The scanning electron microscope results revealed that MgHdoped with 5 wt% KNiFdemonstrated the smallest particle size compared to the as-received and as-milled MgH. It is believed that the formation of in situ active species of KF, KH, and MgNi could provide a synergetic catalytic effect in enhancing the hydrogen sorption properties of MgH.

Hydrogen-transfer conversion of furfural into levulinate esters as potential biofuel feedstock

Furfural is directly converted to levulinate esters（isopropyl levulinate and furan-2-ylmethyl-levulinate） as potential biofuel feedstocks, through a combined catalytic strategy. Nb;O;-ZrO;mixed oxide microspheres are used as bifunctional catalysts for hydrogen-transfer hydrogenation and acid-catalyzed alcoholysis in isopropanol. Bifunctional catalysts improve sustainability of furfural conversion through process intensification. Hydrogen transfer hydrogenation from isopropanol avoids dangerous hydrogen gas, and abates process and environmental costs. Isopropyl levulinate and furan-2-ylmethyl-levulinate are the main products that can be applied as blending components in biodiesel or hydrocarbon fuels.

A Novel Porphyrin-based Hydrogen-bonded Organic Framework

A novel hydrogen-bonded organic framework, HOF-TCPP(HOF = hydrogen bonded organic framework, TCPP = tetrakis(4-carboxyphenyl) porphyrin), has been synthesized via solvothermal reaction in ethylene glycol. Crystal structure was well determined by single-crystal X-ray diffraction and powder X-ray diffraction(PXRD). Topological analysis reveals that HOF-TCPP exhibits sql 2D layer and features 2D → 3D polycatenation. Fluorescence investigation shows that HOF-TCPP displays much higher photoluminescence(PL) intensity than the amorphous ligands TCPP, which can be ascribed to the crystalline structure and hydrogen bonds existing in the structure.

CATALYST DESIGN FOR METHANE DEHYDROGENATION AND BENZENE HYDROGENATION

Highly active and stable nickel catalyst for dehydrogenation of methane and hydrogenation of benzene is prepared from a precursor with hydrotalcite-like anionic clam structure by coprecipitation. The nickel particles have a narrow size distribution in several nanometers, and have a strong interaction with other components such as Al2O3. This catalyst is highly sensitive to further modification by doping and to reaction condition. On a modified catalyst, benzene hydrogenation to cyclohexane proceeds to complete at 373 K. While on another catalyst, different structured nanocarbons are obtained at moderate temperatures. It is found that the thioresistance of the nickel catalyst in hydrogenation can be improved by doping.

Application of Liquid Nitrogen Cold Trap for Purification of Hydrogen Gas Stream Generated from NaBH4

The feasibility of using liquid nitrogen cold trap （LNCT） for the removal of water vapour and alkaline mist from the hydrogen gas stream which is generated from the catalytic and acidic decomposition of sodium borohydride is investigated. Practically, the target application is mobile fuel cells based on hydrogen production from storage in chemical hydrides. The LNCT would be used as a one step purification method with less cost and space requirements instead of applying the conventional purification techniques. Two catalysts were investigated for the production of hydrogen from the aqueous solution of NaBH4 in a small scale packed bed reaction column. The hydrogen generated from the catalytic decomposition of NaBH4 was accompanied by limited quantity of water vapour and alkaline mist. Nonetheless, higher quantities were generated when applying the acidic decomposition of NaBH4 and consequently the utilization of LNCT for H2 purification has proved useful and lead to a reduction in the content of these impurities; thereby the concentration of hydrogen in the outlet stream has increased.

Three New Coordination Polymers Constructed by Adjusting the Angles of Pyridyl or Imidazolyl-based Synthons： Structures and Solid UV-vis Properties

Three new 2D metal-organic frameworks, [M（BIDPE）2（bdc）2]n（M = Co for 1, Ni for 2） and [Ni（PIDPE）2（H2O）2（bdc）]n（3）（BIDPE = 4,4A-bis（imidazol-1-yl） diphenyl ether, PIDPE =4-（pyridyl）-4A-（imidazol-1-yl） diphenyl ether, bdc2- = 1,3-benzenedicarboxylate）, were characterized by single-crystal X-ray diffraction, elemental analysis, PXRD, IR spectroscopy and TGA analysis.Complex 1 crystallizes in monoclinic, space group P21/n, with a = 9.1568（12）, b = 16.943（2）, c =15.441（2） A, β = 104.049（2）°, V = 2323.9（5） A^3, Dc = 1.420 g/cm^3, Mr = 993.83, F（000） = 1026, μ =0.440 mm-（-1） and Z = 2. Complex 2 crystallizes in monoclinic, space group P21/n, with a =9.1395（17）, b = 17.019（3）, c = 15.473（3） A, β = 104.651（2）°, V = 2328.5（7） A^3, Dc = 1.414 g/cm^3,Mr = 991.58, F（000） = 1024, μ = 0.487 mm^-1, Z = 2. Complex 3 also belongs to the monoclinic system, space group P21/n, with a = 11.4365（16）, b = 18.346（3）, c = 11.7068（17） A, β = 91.022（2）°,V = 2455.9（6） A3, Dc = 1.422 g/cm^3, Mr = 1051.66, F（000） = 1092, μ = 0.468 mm^-1, Z = 2. All complexes 1, 2 and 3 are 2D layer structures constructed from intermolecular hydrogen bonds. In addition, the solid UV-vis properties of complexes 1, 2 and 3 were also studied.

Thermodynamic Aspects of the Graphene/Graphane/Hydrogen Systems: Relevance to the Hydrogen On-Board Storage Problem

The present analytical review is devoted to the current problem of thermodynamic stability and related thermodynamic characteristics of the following graphene layers systems: 1) double-side hydrogenated graphene of composition CH (theoretical graphane) (Sofo et al. 2007) and experimental graphane (Elias et al. 2009);2) theoretical single-side hydrogenated graphene of composition CH;3) theoretical single-side hydrogenated graphene of composition C2H (graphone);4) experimental hydrogenated epitaxial graphene, bilayer graphene and a few layers of graphene on SiO2 or other substrates;5) experimental and theoretical single-external side hydrogenated single-walled carbon nanotubes, and experimental hydrofullerene C60H36;6) experimental single-internal side hydrogenated (up to C2H or CH composition) graphene nanoblisters with intercalated high pressure H2 gas inside them, formed on a surface of highly oriented pyrolytic graphite or epitaxial graphene under the atomic hydrogen treatment;and 7) experimental hydrogenated graphite nanofibers-multigraphene with intercalated solid H2 nano-regions of high density inside them, relevant to solving the problem of hydrogen on-board storage (Nechaev 2011-2012).

Semiquantitative determination of some nitrogen compounds by the formation of charge-transfer complexes of diphenylamine with p-dimethylaminobenzaldehyde by capillary solid-state spot-tests

The interactions of p-dimethylaminobenzaldehyde(p-DAB) and potassium hydrogen sulphate(PHS) in equimolar ratio with various concentration of diphenylamine(solid test material) have been investigated by capillary spot-tests technique in order to investigate the effect of temperature and volume of material in test-tube.The formation of the colored boundary in the capillary is taken for the detection of organic compounds by spot-tests at different temperature and volume of solid test material.

固体氧化物电解槽辅助煤电机组深度调峰技术可行性研究

常规的煤电机组灵活性改造方案,难以消除频繁快速变负荷对热力系统造成的潜在寿命折损与设备安全风险。为提高煤电机组参与深度调峰的长期安全性与经济性,以某国产超超临界二次再热1000 MW燃煤机组为应用对象,提出了基于氢储能系统的煤电机组“健康调峰”技术路线,并论证了调峰煤电制氢的间接碳减排意义。在此基础上,分析比较了不同制氢工艺与煤电厂生产条件的匹配程度,认为固体氧化物电解槽(SOEC)制氢为综合最优方案,据此给出了SOEC耦合煤电调峰的原理性设计方案,最后以年度负荷曲线对新方案进行了财务分析。计算结果表明,示例机组自第6年起每年可获得1.07亿元/年的净利润,每年减少碳排放281.92 t,同时获得设备延寿、降耗减碳等其他收益。相关结论对于指导调峰煤电机组的健康安全运行具有参考意义。

二硒化钴电催化剂的制备及氧还原性能测试

具有高附加值的绿色环保型氧化剂——过氧化氢(H_(2)O_(2))的需求日益增加,急需发展绿色且安全的H_(2)O_(2)合成新方法。两电子氧还原反应(2e-ORR)是一种制备H_(2)O_(2)的高效方法,其中催化剂的高效率和高选择性是2e-ORR的关键。对二硒化钴(CoSe_(2))电催化剂的制备和性能测试实验进行了探索。首先,通过联氨还原法制备钴纳米粒子;然后,通过简单的固相反应并在不同温度下退火制备CoSe_(2)电催化剂;最后,通过一系列的表征方法对CoSe_(2)电催化剂的表面形貌、晶型、电化学及其稳定性等进行了研究。为2e^(-)ORR电催化剂CoSe_(2)的进一步研究和应用开发提供借鉴。

Preparation and Characterization of Modified-ZrO_2 Catalysts for the Reaction of CO Hydrogenation

ZrO2 in different structures and CexZr4-xO8 solid solutions have been prepared by a sol-gel related method with propionic acid as the solvent. The results of their characterization and CO hydro-genation performance evaluation show that t-ZrO2 has better catalytic performance for CO hydrogenation to hydrocarbon than m-ZrO2. Cerium (Ⅲ) acetate and zirconium (Ⅳ) acetylacetonate have been chosen as the most suitable starting materials for CexZr4-xO8 solid solution preparation. Ce-Zr reducibility properties are increased by the incorporation of zirconium oxide in the ceria structure. Ce2Zr2O8 exhibits a higher activity, lower methane selectivity and higher iso-C4 selectivity than tetragonal ZrO2. This implies that the formation mechanism of C4 hydrocarbons, especially that for the iso-C4 fraction is different over Ce2Zr2O8 and t-ZrO2.

Preparation of hydrogenated microcrystalline silicon films with hot-wire-assisted MWECR-CVD system

Intrinsic hydrogenated microcrystalline silicon （μc-Si：H） films have been prepared by hot-wire-assisted microwave electron-cyclotron-resonance chemical vapour deposition （HW-MWECR-CVD） under different deposition conditions, Fourier-transform infrared spectra and Raman spectra were measured. Optical band gap was determined by Tauc plots, and experiments of photo-induced degradation were performed. It was observed that hydrogen dilution plays a more essential role than substrate temperature in microcrystalline transformation at low temperatures. Crystalline volume fraction and mean grain size in the films increase with the dilution ratio （R=H2/（H2＋SiH4））. With the rise of crystallinity in the films, the optical band gap tends to become narrower while the hydrogen content and photo-induced degradation decrease dramatically. The samples, were identified as μc-Si：H films, by calculating the optical band gap. It is considered that hydrogen dilution has an effect on reducing the crystallization activation energy of the material, which promotes the heterogeneous solid-state phase transition characterized by the Johnson-Mehl-Avrami （JMA） equation. The films with the needed structure can be prepared by balancing deposition and crystallization through controlling process parameters.

A New Cadmium(Ⅱ) Coordination Polymer Extended through Hydrogen Bonds and π-π Stacking Interactions: Synthesis and Photoluminescence Property

A new coordination polymer, {[Cd(OPY)(tdc)(HO)]·H2 O}n(OPY = 4,4?-(oxybis(4,1-phenylene))dipyridine, H2 tdc = thiophene-2,5-dicarboxylic acid), has been synthesized hydrothermally based on a V-shaped ligand OPY. The structure was fully characterized by elemental analysis, FT-IR spectroscopy, and X-ray single-crystal diffraction analysis. In1, two OPY ligands and one water molecule acted as terminal ligands coordinating to Cdcation to form [Cd(OPY)HO]units, which are then linked by tdc2-ligands to generate a one-dimensional chain. Every two adjacent chains linked by extensive O–H···O hydrogen bonds constitute one-dimensional double-chains, and such chains are extended into two-dimensional layers via O–H···N hydrogen bonds. These layers are further connected to form a three-dimensional supramolecular architecture via π-π stacking interactions. In addition, the thermal stability and solid state fluorescence property of 1 were also investigated.

Hydrogen Sensing Property of Lanthanum Complex Fluoride

Four potentiometer sensor cells have been prepared by using La0.95Pb0.05F2.95 as solid electrolyte(SE) and various materials as electrodes. The sensor cell `Bi(BiF3)|SE|Pt' exhibits the best performance with its 90% response time as short as 75 s to 100 Pa H2 in air at room temperature and with its linear decrease of electromotive force (EMF) with an increase of the logarithm of hydrogen partial pressure in the experimental range. The sensor cell shows weaker response to CO.

Structural and hydrogen storage capacity evolution of Mg_2FeH_6 hydride synthesized by reactive mechanical alloying

Mg-based metal hydrides are promising as hydrogen storage materials for fuel ce ll application. In this work,Mg2FeH6 complex hydride phase was synthesized by controlled reactive ball milling of 2Mg-Fe （atomic ratio） powder mixture in H2. Mg2FeH6 is confirmed to be formed via the following three stages: form ation of MgH2 via the reaction of Mg with H2,incubation stage and formation of Mg2FeH6 by reaction of fully refined MgH2 and Fe. The incubation stage is characterized by no traces of Mg or hydride crystalline phase by XRD. On the other hand,Mg is observed uniformly distributed in the milled powder by SEM-E DS. Also,almost the same amount of H2 as the first stage is detected stored i n the powders of the second stage by DSC and TGA.

新型MgH_(2)固态储氢装置放氢性能影响研究

为探究新型MgH_(2)固态储氢装置放氢性能的影响因素,设计构建了一种新型MgH_(2)固态储氢装置,数值研究了压力、换热流体入口温度、换热流体流速以及有无外环形换热流体层对放氢反应速率的影响。研究结果表明,当压力从0.4 MPa增加至0.6 MPa,放氢反应速率随之降低,但放氢反应完成时间几近一致;当换热流体入口温度从550 K提升至650 K,放氢反应速率迅速上升。与换热流体入口温度600 K相比,换热流体入口温度650 K下的放氢反应完成时间缩短50%;当换热流体流速从1 m/s增加至2 m/s时,放氢反应速率随之增大;增加外环形换热流体层可以大大缩短放氢反应所需时间。与未添加外环形流体层的换热装置的放氢反应时间相比,添加外环形流体层的装置的放氢反应时间可缩短31.25%。

Hydrogen production from steam reforming of ethanol over Ni/MgO-CeO_2 catalyst at low temperature

MgO,CeO2 and MgO-CeO2 with different mole ratio of Mg:Ce were prepared by solid-phase burning method.Catalysts Ni/MgO,Ni/CeO2 and Ni/MgO-CeO2 were prepared by impregnation method.The catalytic properties were evaluated in ethanol steam reforming(ESR) reaction.Specific surface areas of the supports were measured by nitrogen adsorption-desorption at 77 K,and the catalysts were characterized with X-ray diffraction(XRD),temperature programmed reduction(TPR) and thermogravimetric(TG).The results showed that well...