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Sustainable hydrogen and chemical production via photo-electrochemical reforming of biomass-derived alcohols

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Nano Research 2016年第11期9卷 3388-3393页

作者： Liping Zhang Rong Chen Jianqiang Luo Jianwei Miao jiajian gao Bin Liu School of Chemical and Biomedical Engineering Nanyang Technological University 62 Nanyang Drive Singapore 637459 Singapore Energy Research Institute@NTU Interdisciplinary Graduate School Nanyang Technological University Singapore 637141 Singapore

Hydrogen production from steam or autothermal alcohol reforming has been widely studied, but these methods require high temperatures and emit CO2. Here, we present a new strategy for the simultaneous room-temperature production of hydrogen and other chemicals without the emission of CO2, via the photo- electrochemical reforming of biomass-derived alcohols. The measured hydrogen quantum efficiencies reach around 80% across the entire visible solar spectrum from 450 to 850 nm, achieving an ultrahigh hydrogen production rate of 7.91 μmol/（min·cm^2） under AM 1.5G illumination.

关键词： Hydrogen photo-electrochemical reforming biomass-derived alcohols alcohol oxidation

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典型应用场景下软件质量监督方法研究

电子质量 2024年第2期 84-86页

作者：王郑力李振刘思杨高佳健中国人民解放军海军装备部四川成都610036 中国船舶集团工程管理中心北京100080

随着装备体系化、信息化特征愈发明显,软件的作用越来越重要,而软件质量问题隐蔽性强、故障现象各异,质量管理难度大。为了发挥质量监督效能,预防软件质量问题,基于知识图谱技术,创新构建了软件质量监督方法框架,分析了TF-IDF、SIM模型... 详细信息

随着装备体系化、信息化特征愈发明显,软件的作用越来越重要,而软件质量问题隐蔽性强、故障现象各异,质量管理难度大。为了发挥质量监督效能,预防软件质量问题,基于知识图谱技术,创新构建了软件质量监督方法框架,分析了TF-IDF、SIM模型等智能推荐关键技术,设计了智能问答处理流程,围绕装备软件质量监督过程遇到的“新装备”、“新问题”“新验收”“新风险”4种情景,研究了具体的应用模式,为装备软件质量监督,特别是问题解决和质量风险预防提供了有效手段。

关键词：软件质量监督方法

Ni/Al_2O_3 catalysts for CO methanation: Effect of Al_2O_3 supports calcined at different temperatures

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Journal of Energy Chemistry 2013年第6期22卷 919-927页

作者： jiajian gao Chunmiao Jia Jing Li Meiju Zhang Fangna Gu Guangwen Xu Ziyi Zhong Fabing Su State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences University of Chinese Academy of Sciences Institute of Chemical Engineering and Sciences A*star

The correlation between phase structures and surface acidity of Al2O3 supports calcined at different temperatures and the catalytic performance of Ni/Al2O3 catalysts in the production of synthetic natural gas(SNG) via CO methanation was systematically investigated. A series of 10 wt% NiO/Al2O3 catalysts were prepared by the conventional impregnation method, and the phase structures and surface acidity of Al2O3 supports were adjusted by calcining the commercial γ-Al2O3 at different temperatures(600–1200 C). CO methanation reaction was carried out in the temperature range of 300–600 C at different weight hourly space velocities(WHSV = 30000 and 120000 mL·g-1h-1) and pressures(0.1 and 3.0 MPa). It was found that high calcination temperature not only led to the growth in Ni particle size, but also weakened the interaction between Ni nanoparticles and Al2O3 supports due to the rapid decrease of the specific surface area and acidity of Al2O3 supports. Interestingly, Ni catalysts supported on Al2O3 calcined at 1200 C(Ni/Al2O3-1200) exhibited the best catalytic activity for CO methanation under different reaction conditions. Lifetime reaction tests also indicated that Ni/Al2O3-1200 was the most active and stable catalyst compared with the other three catalysts, whose supports were calcined at lower temperatures(600, 800 and 1000 C). These findings would therefore be helpful to develop Ni/Al2O3 methanation catalyst for SNG production.

关键词： Ni catalyst alumina CO methanation synthetic natural gas carbon deposition

Self-assembly of three-dimensional CdS nanosphere/graphene networks for efficient photocatalytic hydrogen evolution

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Journal of Energy Chemistry 2019年第4期28卷 34-38页

作者： Zhijian Wang Zhi Liu Jiazang Chen Hongbin Yang Jianqiang Luo jiajian gao Junming Zhang Cangjie Yang Suping Jia Bin Liu State Key Laboratory of Coal Conversion Institute of Coal Chemistry Chinese Academy of Sciences School of Chemical and Biomedical Engineering Nanyang Technological University

In this work, we report the construction of three-dimensional(3D) CdS nanosphere/graphene networks by a one-step hydrothermal self-assembly route. The 3D graphene networks not only enhance the light scattering, thanks to the interconnected 3D architecture, but also improve the crystallinity of deposited CdS nanospheres, and at the same time provide a direct electron pathway to quickly separate the photogenerated electron-hole pairs from CdS, which thus dramatically improve the photocatalytic *** optimized 3D CdS nanosphere/graphene networks with 2 wt% of graphene could produce molecular hydrogen at a rate of 2310 μmol gcatalyst^(-1) h^(-1) under visible-light illumination(λ > 400 nm).

关键词： CdS nanosphere 3D graphene network Charge transfer Photocatalysis Hydrogen evolution

Design of hierarchical, three-dimensional free-standing single-atom electrode for H2O2 production in acidic media

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Carbon Energy 2020年第2期2卷 276-282页

作者： Jincheng Zhang Hongbin Yang jiajian gao Shibo Xi Weizheng Cai Junming Zhang Ping Cui Bin Liu School of Chemical and Biomedical Engineering Nanyang Technological UniversitySingaporeSingapore Institute of Chemical and Engineering Sciences Agency for ScienceTechnology and ResearchSingaporeSingapore

Electrochemical reduction of molecular O2 to hydrogen peroxide(H2O2)offers a promising solution for water purification and environmental ***,we design a hierarchical free-standing single-Co-atom(with Co-N4 coordination)electrode for oxygen reduction reaction(ORR)via a two-electron pathway to make H2O2 in acidic *** current density of the single-Co-atom electrode reached 51 mA/cm2 at 0.1 V vs reversible hydrogen electrode,lasting for more than 10 hours of continuous operation with H2O2 selectivity greater than 80%.Toward practical application,the single-Co-atom electrode was directly used to assemble an electrochemical cell to produce H2O2 at a rate of 676 mol/kgcat/h with a cell voltage of about 1.6 V.

关键词： CoN4 free-standing H2O2 oxygen reduction reaction single-atom

The thermodynamics analysis and experimental validation for complicated systems in CO_2 hydrogenation process

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Journal of Energy Chemistry 2016年第6期25卷 1027-1037页

作者： Chunmiao Jia jiajian gao Yihu Dai Jia Zhang Yanhui Yang School of Chemical and Biomedical Engineering Nanyang Technological University Institute of High Performance Computing Agency for Science Technology and Research

Catalytic conversion of COinto chemicals and fuels is an alternative to alleviate climate change and ocean *** catalytic reduction of COby Hcan lead to the formation of various products:carbon monoxide,carboxylic acids,aldehydes,alcohols and *** this paper,a comprehensive thermodynamics analysis of COhydrogenation is conducted using the Gibbs free energy minimization *** results show that COreduction to CO needs a high temperature and H/COratio to achieve a high ***,synthesis of methanol from COneeds a relatively high pressure and low temperature to minimize the reverse water-gas shift *** COhydrogenation to formic acid or formaldehyde is thermodynamically *** the contrary,production of CHfrom COhydrogenation is the thermodynamically easiest reaction with nearly 100%CH4 yield at moderate *** addition,complex reactions with more than one product are also calculated in this *** the considered carboxylic acids（HCOOH,CHCOOH and CHCOOH）,propionic acid dominates in the product stream（selectivity above 90%）.The same trend can also be found in the hydrogenation of COto aldehydes and alcohols with the major product of propionaldehyde and butanol,*** the process of COhydrogenation to alkenes,low temperature,high pressure,and high Hpartial pressure favor the *** the most thermodynamically favorable among all considered alkynes under different temperatures and *** thermodynamic calculations are validated with experimental results,suggesting that the Gibbs free energy minimization method is effective for thermodynamically understanding the reaction network involved in the COhydrogenation process,which is helpful for the development of high-performance catalysts.

关键词： CO2 hydrogenation Thermodynamics analysis Gibbs free energy minimization method

Coking-resistant Ni-ZrO_2/Al_2O_3 catalyst for CO methanation

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Journal of Energy Chemistry 2014年第6期23卷 761-770页

作者： Qing Liu Fangna Gu jiajian gao Huifang Li Guangwen Xu Fabing Su State Key Laboratory of Multiphase Complex Systems Institute of Process Engineering Chinese Academy of Sciences

Highly coke-resisting ZrO2-decorated Ni/A1203 catalysts for CO methanation were prepared by a two-step process. The support was first loaded with NiO by impregnating method and then modified with ZrO2 by deposition-precipitation method （IM-DP）. Nitrogen adsorption- desorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetdc analysis, H2 temperature- programmed reduction and desorption, NH3 temperature-programmed desorption, and zeta potential analysis were employed to characterize the samples. The results revealed that, compared with the catalysts with the same composition prepared by co-impregnation （CI） and sequential impregnation （SI） methods, the Ni/A1203 catalyst prepared by IM-DP showed much enhanced catalytic performance for syngas methanation under the condition of atmospheric pressure and a high weight hourly space velocity of 120000 mL.g-1 .h-1. In a 80 h life time test under the condition of 300-600 ~C and 3.0 MPa, this catalyst showed high stability and resistance to coking, and the amount of deposited carbon was only 0.4 wt%. On the contrary, the deposited carbon over the catalyst without ZrO2 reached 1.5 wt% after a 60 h life time test. The improved catalytic performance was attributed to the selective deposition of ZrO2 nanoparticles on the surface of NiO rather than A1203, which could he well controlled via changing the electrostatic interaction in the DP procedure. This unique structure could enhance the dissociation of CO2 and generate surface oxygen intermediates, thus preventing carbon deposition on the Ni particles in syngas methanation.

关键词： Ni/γ-A1203 ZrO2 coke resistance syngas methanation

Enhancing catalytic toluene oxidation over MnO2@Co3O4 by constructing a coupled interface

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Chinese Journal of Catalysis 2020年第12期41卷 1873-1883页

作者： Quanming Ren Shengpeng Mo Jie Fan Zhentao Feng Mingyuan Zhang Peirong Chen jiajian gao Mingli Fu Limin Chen Junliang Wu Daiqi Ye School of Environment and Energy South China University of TechnologyGuangzhou 510006GuangdongChina National Engineering Laboratory for VOCs Pollution Control Technology and Equipment South China University of TechnologyGuangzhou 510006GuangdongChina Guangdong Provincial Key Laboratory of Atmospheric Environment and Pollution Control Guangdong Provincial Engineering and Technology Research Centre for Environmental Risk Prevention and Emergency DisposalSouth China University of TechnologyGuangzhou 510006GuangdongChina School of Chemical and Biomedical Engineering Nanyang Technological University62 Nanyang DriveSingapore 637459Singapore

Herein,a bottom-down design is presented to successfully fabricate ZIF-derived Co3O4,grown in situ on a one-dimensional(1D)α-MnO2 material,denoted as α-MnO2@*** synergistic effect derived from the coupled interface constructed betweenα-MnO2 and Co3O4 is responsible for the enhanced catalytic *** resultantα-MnO2@Co3O4 catalyst exhibits excellent catalytic activity at a T90%(temperature required to achieve a toluene conversion of 90%)of approximately 229℃,which is 47 and 28℃ lower than those of the pureα-MnO2 nanowire and Co3O4-b obtained via pyrolysis of ZIF-67,*** activity is attributed to the increase in the number of surface-adsorbed oxygen species,which accelerate the oxygen mobility and enhance the redox pairs of Mn^4+/Mn^3+ and Co^2+/Co^3+.Moreover,the result of in situ diffuse reflectance infrared Fourier transform spectroscopy suggests that the gaseous oxygen could be more easily activated to adsorbed oxygen species on the surface of α-MnO2@Co3O4 than on that of α-*** catalytic reaction route of toluene oxidation over theα-MnO2@Co3O4 catalyst is as follows:toluene→benzoate species→alkanes containing oxygen functional group→CO2 and *** addition,the α-MnO2@Co3O4 catalyst shows excellent stability and good water resistance for toluene ***,the preparation method can be extended to other 1D MnO2 materials.A new strategy for the development of high-performance catalysts of practical significance is provided.

关键词： MnO2@Co3O4 Toluene oxidation Synergistic effect Coupled interface In situ DRIFTS

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测向天线基线选择对测量精度影响的研究

航天电子对抗 2023年第3期39卷 15-20页

作者：王晨航高加健徐璐张一嘉浙江理工大学信息科学与工程学院浙江杭州310018 四川九洲电器集团有限责任公司四川绵阳621000

无线电测向应用广泛,常用的天线阵列类型有线阵、圆阵和椭圆阵等。设计天线阵列时,需要考虑天线尺寸、阵列构成等因素对测向精度的影响,以保证系统性能指标。首先,构建了针对五元线阵和五元均匀圆阵的干涉测向模型,采用了一种基于平行... 详细信息

无线电测向应用广泛,常用的天线阵列类型有线阵、圆阵和椭圆阵等。设计天线阵列时,需要考虑天线尺寸、阵列构成等因素对测向精度的影响,以保证系统性能指标。首先,构建了针对五元线阵和五元均匀圆阵的干涉测向模型,采用了一种基于平行虚拟基线选择完成测向解模糊的方法,将相位测量值与测向理论数据库进行相关,相关最大值所对应的角度即为来波方向。其次,分别分析了测向过程中的频率灵敏度和角度灵敏度所引起的测向误差。最后,通过MonteCarlo仿真,分析了相位误差在15°的标准偏差条件下的测向误差,并获取测向精度分布图,为实际应用时天线阵列设计提供参考。

关键词：无线电测向阵列基线相关法测量精度