Synthesis gas production using oxygen storage materials as oxygen carrier over circulating fluidized bed

A novel process for synthesis gas production over Circulating Fluidized Bed （CFB） using oxygen storage materials as oxygen carder was reported. First, oxygen in the air was chemically fixed and converted to lattice oxygen of oxygen storage materials over regenerator, and then methane was selectively oxidized to synthesis gas with lattice oxygen of oxygen storage materials over riser reactor. The results from simulation reaction of CFB by sequential redox reaction on a fixed bed reactor using lanthanum-based perovskite LaFeO3 and La0.8Sr0.2Fe0.9CO0.1O3 oxides prepared by sol-gel, suggested that the depleted oxygen species could be regenerated, and methane could be oxidized to synthesis gas by lattice oxygen with high selectivity. The partial oxidation of methane to synthesis gas over CFB using lattice oxygen of the oxygen storage materials instead of gaseous oxygen should be possibly applicable.

Boosting Hydrogen Storage Performance of MgH_(2) by Oxygen Vacancy-Rich H-V_(2)O_(5) Nanosheet as an Excited H-Pump

MgH_(2) is a promising high-capacity solid-state hydrogen storage material,while its application is greatly hindered by the high desorption temperature and sluggish kinetics.Herein,intertwined 2D oxygen vacancy-rich V_(2)O_(5) nanosheets(H-V_(2)O_(5))are specifically designed and used as catalysts to improve the hydrogen storage properties of MgH_(2).The as-prepared MgH_(2)-H-V_(2)O_(5) composites exhibit low desorption temperatures(Tonset=185℃)with a hydrogen capacity of 6.54 wt%,fast kinetics(Ea=84.55±1.37 kJ mol^(-1) H_(2) for desorption),and long cycling stability.Impressively,hydrogen absorption can be achieved at a temperature as low as 30℃ with a capacity of 2.38 wt%within 60 min.Moreover,the composites maintain a capacity retention rate of~99%after 100 cycles at 275℃.Experimental studies and theoretical calculations demonstrate that the in-situ formed VH_(2)/V catalysts,unique 2D structure of H-V_(2)O_(5) nanosheets,and abundant oxygen vacancies positively contribute to the improved hydrogen sorption properties.Notably,the existence of oxygen vacancies plays a double role,which could not only directly accelerate the hydrogen ab/de-sorption rate of MgH_(2),but also indirectly affect the activity of the catalytic phase VH_(2)/V,thereby further boosting the hydrogen storage performance of MgH_(2).This work highlights an oxygen vacancy excited“hydrogen pump”effect of VH_(2)/V on the hydrogen sorption of Mg/MgH_(2).The strategy developed here may pave a new way toward the development of oxygen vacancy-rich transition metal oxides catalyzed hydride systems.

Tailoring NH_(4)^(+)storage by regulating oxygen defect in ammonium vanadate

Defect engineering is an effective strategy for modifying the energy storage materials to improve their electrochemical performance.However,the impact of oxygen defect and its content on the electrochemical performances in the burgeoning aqueous NH_(4)^(+)storage field remains explored.Therefore,for the first time in this work,an oxygen-defective ammonium vanadate[(NH_(4))_(2)V_(10)O_(25)·8H_(2)O,denoted as Od-NHVO]with a novel 3D porous flower-like architecture was achieved via the reduction of thiourea in a mild reaction condition,which is a facile method that can realize the intention to regulate the oxygen defect content,with the capability of mass-production.The as-prepared Od_M-NHVO with moderate oxygen defect content can deliver a stable specific capacitance output(505 F g^(-1),252 mAh g^(-1)at 0.5 A g^(-1)with~80% capacitance retention after 10,000 cycles),which benefits from extra active sites,unimpeded NH_(4)^(+)-migration path and relatively high structure integrity.In contrast,low oxygen defect content will lead to the torpid electrochemical reaction kinetics while too high content of it will reduce the chargestorage capability and induce structural disintegration.The superior NH_(4)^(+)-storage behavior is achieved with the reversible intercalation/deintercalation process of NH_(4)^(+)accompanied by forming/breaking of hydrogen bond.As expected,the assembled flexible OdM-NHVO//PTCDI quasi-solid-state hybrid supercapacitor(FQSS HSC)also exhibits high areal capacitance,energy density and reliable flexibility.This work provides a new avenue for developing materials with oxygen-deficient structure for application in various aqueous non-metal cation storage systems.

The preparation and properties of N-doped carbon materials and their use for sodium storage

Defect engineering by heteroatom doping gives carbon materials some new characteristics such as a different electronic structure and a high electrochemical activity,making them suitable for high-performance applications.N-doping has been widely investigated because of its similar atom radius to carbon,high electronegativity as well as many different configurations.We summarize the preparation methods and properties of N-doped carbon materials,and discuss their possible use in sodium ion storage.The relationships between N content/configuration and crystallinity,electronic conductivity,wettability,chemical reactivity as well as sodium ion storage performance are discussed.

Phase separation-hydrogen etching-derived Cu-decorated Cu-Mn bimetallic oxides with oxygen vacancies boosting superior sodium-ion storage kinetics

Understanding the crystal phase evolution of bimetallic oxide anodes is the main concern to profoundly reveal the conversion reaction kinetics and sodium-ion storage mechanisms.Herein,an integrated selfsupporting anode of the Cu-decorated Cu-Mn bimetallic oxides with oxygen vacancies(Ov-BMO-Cu)are in-situ generated by phase separation and hydrogen etching using nanoporous Cu-Mn alloy as selfsacrificial templates.On this basis,we have elucidated the relationship between the phase evolution,oxygen vacancies and sodium-ion storage mechanisms,further demonstrating the evolution of oxygen vacancies and the inhibition effect of manganese oxides as an“anchor”on grain aggregation of copper oxides.The kinetic analyses confirm that the expanded lattice space and increased oxygen vacancies of cycled Ov-BMO-Cu synergistically guarantee effective sodium-ion diffusion and storage mechanisms.Therefore,the Ov-BMO-Cu electrode exhibits higher reversible capacities of 4.04 mA h cm^(-2)at 0.2 mA cm^(-2)after 100 cycles and 2.20 m A h cm^(-2)at 1.0 mA cm^(-2)after 500 cycles.Besides,the presodiated Ov-BMO-Cu anode delivers a considerable reversible capacity of 0.79 m A h cm^(-2)at 1.0 mA cm^(-2)after 60 cycles in full cells with Na_(3)V_(2)(PO_(4))_(3)cathode,confirming its outstanding practicality.Thus,this work is expected to provide enlightenment for designing high-capacity bimetallic oxide anodes.

Dynamic Oxygen Storage Capacity Measurements on Ceria-Based Material

Dynamic oxygen storage and release capability （OSC） measurement apparatus was designed to evaluate the OSC performance of ceria-based oxygen storage material. The optimum measurement condition was at a frequency of 0.1 Hz with the inlet gas-flow sequence CO （5S）→O2（5S）→CO→O2 and a flow rate of 300 ml·min^-1. Under this condition, similar regular square wave in the inlet and outlet of the reactor was obtained to guarantee the reliability of the dynamic OSC results. The dynamic OSC performance of the CeO2 and Ce0.67Zr0.33O2 mixed oxide prepared using the citric sol-gel method was studied at the optimum measurement condition with focus on both quantitative and qualitative analyses, The results reveal distinctly that Ce0.67Zr0.33O2 had better dynamic OSC performance because of its higher oxygen migration rate than CeO2. Under dynamic conditions, two CO2 production peaks occurred corresponding to the CO pulse and the O2 pulse, respectively, during the entire cycle. The intensity and ratio between the two CO2 productions were highly influenced by temperature and frequency indicating complex surface phenomena during the oxygen storage/release process, As a result, this set-up can be applied to the evaluation of ceria-based material on the OSC performance.

Effects of 1-MCP and Chitosan on Active Oxygen Metabolism and Quality of Fresh-cut Potato during Storage

[Objective] The research aimed to study the effects of 1-methylcyclopropene （1-MCP） and chitosan on active oxygen metabolism and quality of fresh-cut potato during storage. [Method] The fresh-cut potato slices were respectively treated with 1- MCP （2 μl/L）, chitosan or 1-MCP ＋ chitosan. During the storage period, the contents of superoxide anion （02）, malondialdehyde （MDA）, hydrogen dioxide （H202） and Vita- min C （Vc）, the activities of polyphenol oxidase （PPO）, peroxydase （POD） and super- oxide dismutase （SOD） as well as the respiratory rate of the fresh-cut potatoes in all the treatments were determined every day. The fresh-cut potato slices treated without any reagents were used as control. [Result] 1-MCP Treated could significantly de- creased the respiratory rate, PPO activity and the accumulations of 02 , H202 and MDA, increased the activities of SOD and POD and slowed down Vc content reduc- tion. On the contrary, potato treated with chitosan significantly inhibited the POD activi- ty in fresh-cut potato. Compared with the control, the combination of 1-MCP and chi- tosan showed a little but not significant better effects on potato preservation. [Conclu- sion] 1-MCP Treated showed the best effects on potato preservation.

Oxygen Vacancy-Rich 2D TiO_(2) Nanosheets:A Bridge Toward High Stability and Rapid Hydrogen Storage Kinetics of Nano-Confined MgH_(2)

MgH_(2) has attracted intensive interests as one of the most promising hydrogen storage materials.Nevertheless,the high desorption temperature,sluggish kinetics,and rapid capacity decay hamper its commercial application.Herein,2D TiO_(2) nanosheets with abundant oxygen vacancies are used to fabricate a flower-like MgH_(2)/TiO_(2) heterostructure with enhanced hydrogen storage performances.Particularly,the onset hydrogen desorption temperature of the MgH_(2)/TiO_(2) heterostructure is lowered down to 180℃(295℃ for blank MgH_(2)).The initial desorption rate of MgH_(2)/TiO_(2) reaches 2.116 wt% min^(-1) at 300℃,35 times of the blank MgH_(2) under the same conditions.Moreover,the capacity retention is as high as 98.5% after 100 cycles at 300℃,remarkably higher than those of the previously reported MgH_(2)-TiO_(2) composites.Both in situ HRTEM observations and ex situ XPS analyses confirm that the synergistic effects from multi-valance of Ti species,accelerated electron transportation caused by oxygen vacancies,formation of catalytic Mg-Ti oxides,and stabilized MgH_(2) NPs confined by TiO_(2) nanosheets contribute to the high stability and kinetically accelerated hydrogen storage performances of the composite.The strategy of using 2D substrates with abundant defects to support nano-sized energy storage materials to build heterostructure is therefore promising for the design of high-performance energy materials.

Oxygen Storage Capacity of Pt-, Pd-, Rh/CeO_2-Based Oxide Catalyst

CZO （CeO2-ZrO2） and CZYO （CeO2-ZrO2-Y2O3） series of mixed oxides were prepared by coprecipitaion, and a part of these oxides were loaded with precious metals （PM）. XRD, BET, and oxygen storage capacity （OSC） investigations were performed on samples aged at 750, 900, and 1050 ℃. It was observed that BET surface area and OSC showed a marked decrease in CeO2 aged at high temperature, and the erystallite size showed an obvious increase. The CZO samples consist of cubic- and tetragonal crvstal phases, and their crystallite size increase rapidly when aged at high temperature. The CZYO samples consist of single crystal phase when the content of Y exceeds 0.15 mol, and their erystallite size increases slowly during high-temperature aging. It is concluded that additive Y can stabilize the performance of CZYO oxides. In the aged CZO and CZYO mixed-oxide systems, addition of a small amount of precious metals （Pt, Pd, Rh） increased the rate of reduction and led to an obvious improvement in OSC. OSC of CZO and CZYO with precious metals are related to their composition and the type of precious metal.

Oxygen Evolution Reaction in Energy Conversion and Storage: Design Strategies Under and Beyond the Energy Scaling Relationship

The oxygen evolution reaction(OER)is the essential module in energy conversion and storage devices such as electrolyzer,rechargeable metal–air batteries and regenerative fuel cells.The adsorption energy scaling relations between the reaction intermediates,however,impose a large intrinsic overpotential and sluggish reaction kinetics on OER catalysts.Developing advanced electrocatalysts with high activity and stability based on non-noble metal materials is still a grand challenge.Central to the rational design of novel and high-efficiency catalysts is the development and understanding of quantitative structure–activity relationships,which correlate the catalytic activities with structural and electronic descriptors.This paper comprehensively reviews the benchmark descriptors for OER electrolysis,aiming to give an in-depth understanding on the origins of the electrocatalytic activity of the OER and further contribute to building the theory of electrocatalysis.Meanwhile,the cutting-edge research frontiers for proposing new OER paradigms and crucial strategies to circumvent the scaling relationship are also summarized.Challenges,opportunities and perspectives are discussed,intending to shed some light on the rational design concepts and advance the development of more efficient catalysts for enhancing OER performance.

Novel Oxygen Storage Components Promoted Palladium Catalysts for Emission Control in Natural Gas Powered Engines

A three-way catalyst comprised novel oxygen storage components for emission control in natural gas powered engines was prepared. The addition of novel oxygen storage components to the Pd/γ-Al2O3 catalysts resulted in improved activities of the fresh and aged catalyst by lowering the light-off temperature for methane in natural gas engines exhaust.

Oxygen Storage Capacity and Adsorptive Property of Praseodymium Oxides

Oxygen storage and adsorptive properties of praseodymium oxides were investigated by pulse experiments and temperature - programmed desportion/reduction (TPD/TPR) experiments. Pr2O3 possesses the similar oxygen storage properties to CeO2, and its dynamic oxygen storage capacity is 14.9 mumol.g(-1). The studies on TPD Of O-2, H2O and CO and TPR show that Pr2O3 provides more active surface oxygen species and at a lower temperature than CeO2. It is suggested that Pr2O3 can be a well candidate as an oxygen storage component in automobile three-way catalyst.

Role of Surface Adsorption in Fast Oxygen Storage/Release of CeO_2-ZrO_2 Mixed Oxides

Four kinds of CeO2-ZrO2 mixed oxides, i.e., a physical mixture of ceria and zirconia （CZP）, zirconia-coated ceria （ZCC）, ceria-coated zirconia （CCZ） and a chemical mixture of celia and zirconia （CZC）, were prepared. The oxygen storage capacity （OSC） measurements at 500℃ were performed under transient and stationary reaction conditions. All the curves of CO2 evolution during CO-O2 cycles presented a bimodal shape. The fast peak was primarily the result of the reaction of CO with the oxygen from the oxides, which was mainly determined by the nature of the material The sec- ond peak was mostly related to the CO2 adsorption behavior and was highly influenced by the surface area and the number of surface active sites. As a result, OSC activity of the samples followed in the order of CZC 〉 CCZ 〉 ZCC=CZP.

Modeling of the Dissolved Oxygen in a River with Storage Zone on the Banks

The prediction of water quality in terms of variables like dissolved oxygen (DO), biochemical oxygen demand (BOD), pH value, total dissolved solids (TDS) and salinity etc. is useful for evaluating the use of water for various related purposes. The widely used Streeter and Phelps models for computing biochemical oxygen demand and its impact on dissolved oxygen do not account for the settleable component of BOD and related implications. The model also does not account for the impact of storage zone on the stream’s DO. In the present work an attempt is made to develop a model which simultaneously accounts for the settleable component of BOD and the effect of storage zones onriver’s DO. An application of the model to real field data suggests that the cumulative impact of settleable BOD and presence of storage zone in the river is to shift the critical deficit closer to the point source and magnify its amount.

Nanostructured energy materials for electrochemical energy conversion and storage: A review

Nanostructured materials have received tremendous interest due to their unique mechanical/electrical properties and overall behavior contributed by the complex synergy of bulk and interfacial properties for efficient and effective energy conversion and storage. The booming development of nanotechnology affords emerging but effective tools in designing advanced energy material. We reviewed the significant progress and dominated nanostructured energy materials in electrochemical energy conversion and storage devices, including lithium ion batteries, lithium-sulfur batteries, lithium-oxygen batteries, lithium metal batteries, and supercapacitors. The use of nanostructured electrocatalyst for effective electrocatalysis in oxygen reduction and oxygen evolution reactions for fuel cells and metal-air batteries was also included. The challenges in the undesirable side reactions between electrolytes and electrode due to high electrode/electrolyte contact area, low volumetric energy density of electrode owing to low tap density, and uniform production of complex energy materials in working devices should be overcome to fully demonstrate the advanced energy nanostructures for electrochemical energy conversion and storage. The energy chemistry at the interfaces of nanostructured electrode/electrolyte is highly expected to guide the rational design and full demonstration of energy materials in a working device. (C) 2016 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. and Science Press. All rights reserved.

Preparation and Characterization of Storage and Emission Functional Material of Cs2O-doped 12CaO.7Al2O3

We provides a novel approach to generate low-temperature atomic oxygen anions （O-） emission using the cesium oxide-doped 12CaO.7Al2O3 （Cs2O-doped C12A7）. The maximal emission intensity of O- from the Cs2O-doped C12A7 at 700℃ and 800 V/cm reached about 0.54μA/cm2, which was about two times as strong as that from the un-doped C12A7 （0.23 μA/cm2） under the same condition. The initiative temperature of the O- emission from the Cs2O-doped C12A7 was about 500 ℃, which was also much lower than the initiative temperature from the un-doped C12A7 （570 ℃） in the given field of 800 V/cm. High pure O- emission close to 100% could be obtained from the Cs2O-doped C12A7 under the lower temperature （〈550℃）. The emission features of the Cs2O-doped C12A7, including the emission distribution, temperature effect, and emission branching ratio have been investigated in detail and compared with the un-doped C12A7. The structure and storage characteristics of the resulting material were also investigated via X-ray diffraction and electron paramagnetic resonance. It was found that doping Cs2Oto C12A7 will lower the initiative emission temperature and enhance the emission intensity

Enhancing hydrogen storage performance via optimizing Y and Ni element in magnesium alloy

Magnesium-based hydrogen storage materials are considered as one of the most promising candidates for solid state hydrogen storage due to their advantages of high hydrogen capacity,excellent reversibility and low cost.In this paper,Mg_(91.4)Ni_(7)Y_(1.6) and Mg_(92.8)Ni_(2.4)Y_(4.8) alloys were prepared by melting and ball milling.Their microstructures and phases were characterized by X-ray diffraction,scanning electron microscope and transmission electron microscope,and hydrogen absorbing and desorbing properties were tested by the high pressure gas adsorption apparatus and differential scanning calorimetry(DSC).In order to estimate the activation energy and growth mechanism of alloy hydride,the JMAK,Arrhenius and Kissinger methods were applied for calculation.The hydrogen absorption content of Mg_(92.8)Ni_(2.4)Y_(4.8) alloy reaches 3.84 wt.%within 5 min under 350℃,3 MPa,and the maximum hydrogen capacity of the alloy is 4.89 wt.%in same condition.However,the hydrogen absorption of Mg_(91.4)Ni_(7)Y_(1.6) alloy reaches 5.78 wt.%within 5 min,and the maximum hydrogen absorption of the alloy is 6.44 wt.%at 350℃and 3 MPa.The hydrogenation activation energy of Mg_(94.4)Ni_(7)Y_(1.6) alloy is 25.4 kJ/mol H_(2),and the enthalpy and entropy of hydrogen absorption are-60.6 kJ/mol H_(2) and 105.5 J/K/mol H_(2),separately.The alloy begins to dehydrogenate at 210℃,with the dehydrogenation activation energy of 87.7 kJ/mol H_(2).By altering the addition amount of Ni and Y elements,the 14 H-LPSO phase with smaller size and ternary eutectic areas with high volume fraction are obtained,which provides more phase boundaries and catalysts with better dispersion,and there are a lot of fine particles in the alloy,these structures are beneficial to enhance the hydrogen storage performance of the alloys.

Time-Temperature Charge Function of a High Dynamic Thermal Heat Storage with Phase Change Material

A thermal heat storage system with an energy content of 40 kWh and a temperature of 58°C will be presented. This storage system is suitable for supporting the use of renewable energies in buildings and for absorbing solar heat, heat from co-generation and heat pumps or electric heat from excess wind and solar power. The storage system is equipped with a plate heat exchanger that is so powerful that even with small temperature differences between the flow temperature and the storage temperature a high load dynamic is achieved. The storage system has a performance of 2.8 kW at 4 K and 10.6 kW at a temperature difference of 10 K. Thus, large performance variations in solar thermal systems or CHP plants can be buffered very well. Further a storage charge function Q(T, t) will be presented to characterize the performance of the storage.

The Electrochemical Performance of Ml_(0.7) Mm_(0.3) Ni(3.7) Co_(0.7) Mn_(0.4) Al_(0.2) Nanocrystalline Hydrogen Storage Alloy as Metal Hydride Electrode

Ml 0.7 Mm 0.3 Ni 3.7 Co 0.7 Mn 0.4 Al 0.2 nanocrystalline hydrogen storage materials are prepared by melt spinning (MS). X ray diffraction is used for the measurement of the nanocrystalline size. Compared to the electrode of polycrystalline alloys, the property of activation MH (metal hydride) electrode of the alloys with nanometer scale became worse and the initial discharge capacity decreased. It may be ascribed to the decrease of the total amount of rare earth metals and the increase of oxygen on the surface from the analysis of components of the alloys. After heat treatment, the electrochemical performance of MH electrode of as spun alloys could be improved, which could be attributed to the alleviation of the lattice strain.

Thermal Distribution Performance of NPCM: NaCl, NaNO₃and KNO₃in the Thermal Storage System

The experiment is studied on thermal distribution in the thermal energy storage system with non-phase change materials (NPCM): NaNO3, KNO3 and NaCl in the range of 25°C - 250°C. The cylindrical storage system was made of stainless steel with 25.6 cm-diameter and 26.8 cm-height that was contained of these NPCM. There was one pipe for heat transfer fluid (HTF) with 1.27 cm-diameter that manipulates in the storage tank and submerges to NPCM. The inner pipe was connected to the 2.27 cm-diameter outer HTF tube. The tube was further connected to the thermal pump, heater and load. The pump circulates the synthetic oil (Thermia oil) within the pipe for heat transferring purposes (charging and discharging). An electric heater is used as the heat source. The limitation of the charging oil temperature is maintained at 250°C with the flow rates in the range of 0.58 to 1.45 kg/s whereas the inlet temperature of the discharge oil is maintained at 25°C. Thermal performances of TES (thermal energy storage) such as charging and discharging times, radial thermal distribution, energy storage capacity and energy efficiency have been evaluated. The experimental results show that the radial thermal distribution of NaCl for TR inside, TR middle and TR outside was optimum of temperature down to NaNO3 and KNO3 respectively. Comparison of NPCMs with oil, flow rates for NaCl were charging and discharging heat transfer than KNO3 and NaNO3. The thermal stored NaCl ranged from 5712 - 5912 J;KNO3 ranged from 7350 - 7939 J and NaNO3 ranged from 6623 - 6930 J respectively. The thermal energy stored for experimental results got with along the KNO3, NaNO3 and NaCl respectively. The thermal energy efficiency of NaCl, KNO3 and NaNO3 was in the range 66% - 70%.