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First-principles characterization of formate and carboxyl adsorption on stoichiometric CeO_2(111)and CeO_2(110) surfaces

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Journal of Energy Chemistry 2013年第3期22卷 524-532页

作者： donghai mei Institute for Integrated Catalysis Pacific Northwest National LaboratoryRichlandWashington 99352USA

Molecular adsorption of formate and carboxyl on stoichiometric CeO2（111） and CeO2（110） surfaces was studied using periodic density functional theory （DFT＋U） calculations. Two distinguishable adsorption modes （strong and weak） of formate are identified. The bidentate configuration is more stable than the monodentate adsorption configuration. Both formate and carboxyl bind at the more open CeO2（110） surface are stronger. The calculated vibrational frequencies of two adsorbed species are consistent with the experimental measurements. Fi- nally, the effects of U parameters on the adsorption of formate and carboxyl over both CeO2 surfaces were investigated. We found that the geometrical configurations of two adsorbed species are not affected by different U parameters （U = 0, 5, and 7）. However, the calculated ad- sorption energy of carboxyl pronouncedly increases with the U value while the adsorption energy of formate only slightly changes （〈0.2 eV）. The Bader charge analysis shows the opposite charge transfer occurs for formate and carboxyl adsorption where the adsorbed formate is neg- atively charge while the adsorbed carboxyl is positively charged. Interestingly, with the increasing U parameter, the amount of charge is also increased.

关键词： cerium oxide adsorption formate carboxyl density functional theory

La ions-enhanced NH_(3)-SCR performance over Cu-SSZ-13 catalysts

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Nano Research 2023年第10期16卷 12126-12133页

作者： Mengyang Chen Wenru Zhao Yingzhen Wei Jinfeng Han Junyan Li Chang Sun donghai mei Jihong Yu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin UniversityChangchun 130012China School of Materials Science and Engineering Tiangong UniversityTianjin 300387China International Center of Future Science Jilin UniversityChangchun 130012China

Lanthanum(La)ions are generally recognized to cause a decline of the catalytic performance for Cu-SSZ-13 zeolite in the selective catalytic reduction of NO_(x)with NH_(3)(NH_(3)-SCR).Herein,we demonstrate that the NH_(3)-SCR performance and hydrothermal stability of Cu-La-SSZ-13 zeolites can be enhanced with the incorporation of a small amount of La *** incorporation of La ions into SSZ-13 favors more Z_(2)Cu^(2+)ions at six-membered rings(6MRs),which results in higher hydrothermal stability of Cu-La-SSZ-13 than that of *** NO conversion of Cu-La-SSZ-13 achieves 5%–10%higher than that of Cu-SSZ-13 at the temperature range of 400–550℃ after hydrothermal *** introducing excess amount of La ions in SSZ-13 may cause the formation of inactive CuO_(x),leading to the decrease of catalytic activity and hydrothermal ***,the low-temperature activity of Cu-SSZ-13 with a low Cu content(≤2 wt.%)can be boosted by the introduction of La ions,which is largely due to the improved redox ability of Cu active sites modified by La *** functional theory(DFT)calculations indicate that La ions prefer to locate at eight-membered rings(8MRs)and thus promoting the formation of more Z_(2)Cu^(2+)***,the existence of La ions in SSZ-13 inhibits the dealumination process and the transformation from Z_(2)Cu^(2+)to CuO_(x),resulting in its enhanced hydrothermal *** present work sheds a new insight into the regulation of secondary metal cations for promoting high NH_(3)-SCR performance over Cu-SSZ-13 zeolite catalysts.

关键词： zeolite bimetallic catalyst Cu-SSZ-13 lanthanum ammonia selective catalytic reduction(NH_(3)-SCR)

Synergistic effect of the metal-support interaction and interfacial oxygen vacancy for CO_(2) hydrogenation to methanol over Ni/In_(2)O_(3) catalyst:A theoretical study

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Journal of Energy Chemistry 2022年第2期31卷 623-629页

作者： Chenyang Shen Qianqian Bao Wenjuan Xue Kaihang Sun Zhitao Zhang Xinyu Jia donghai mei Chang-jun Liu Collaborative Innovation Center of Chemical Science&Engineering School of Chemical Engineering and TechnologyTianjin UniversityTianjin 300072China State Key Laboratory of Membrane Separation and Membrane Processes School of Environmental Science and EngineeringTiangong UniversityTianjin 300387China

Indium oxide supported nickel catalyst has been experimentally confirmed to be highly active for CO_(2) hydrogenation towards *** this work,the reaction mechanism for CO_(2) hydrogenation to methanol has been investigated on a model Ni/In_(2)O_(3) catalyst,i.e.,Ni_(4)/In_(2)O_(3),via the density functional theory(DFT)*** possible reaction pathways,i.e.,the formate pathway,CO hydrogenation and the reverse water-gas-shift(RWGS)pathways,have been examined on this model *** has been demonstrated that the RWGS pathway is the most theoretically-favored for CO_(2) hydrogenation to *** complete RWGS pathway follows CO_(2)+6 H→COOH+5 H→CO+H_(2)O+4 H→HCO+H_(2)O+3 H→H_(2)CO+H_(2)O+2 H→H_(3)CO+H_(2)O+H→H_(3)COH+H_(2) ***,it has been also proved that the interfacial oxygen vacancy can serve as the active site for boosting the CO_(2) adsorption and charge transfer between the nickel species and indium oxide,which synergistically promotes the consecutive CO_(2) hydrogenation towards methanol.

关键词： CO_(2)hydrogenation Indium oxide Nickel Methanol synthesis Oxygen vacancy Density functional theory

Air-Steam Etched Construction of Hierarchically Porous Metal-Organic Frameworks

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Chinese Journal of Chemistry 2021年第6期39卷 1538-1544页

作者： Hongliang Huang Yuxiu Sun Xuemeng Jia Wenjuan Xue Chenxu Geng Xin Zhao donghai mei Chongli Zhong State Key Laboratory of Separation Membranes and Membrane Processes School of Chemistry and Chemical EngineeringTiangong UniversityTianjin 300387China

The introduction of mesoporosity into the microporous metal-organic frameworks(MOFs)is expected to expand their ***,we report a green and facile method to obtain hierarchically porous MOF structures by using an air-steam etching *** virtue of the protonation reaction between the imidazole moiety and water vapor,the protonated imidazole related linkers leave the framework,resulting in the formation of mesopores in the zeolitic imidazolate frameworks(ZIFs),as exemplified by *** the mild etching process,the materials'structural integrity and crystallinity are well ***,the hierarchical porous ZIF-8 exhibited enhanced performance in the dye removal as well as CO_(2) cycloaddition reaction with epichlorohydrin in comparison with microporous ZIF-8,owing to the accelerated mass transfer arising from mesoporous ***,the proposed steam etching approach is generally applicable,which can be readily extended to other ZIFs,such as ZIF-14,ZIF-69,and ZIF-71,thus representing a powerful strategy to construct hierarchically porous MOF materials.

关键词： Mesoporous materials Metal-organic frameworks Cycloaddition Steam etching Dye removal

Integrating Zeolite and Layered Double Hydroxide for Highly Selective Catalytic Production ofγ-Valerolactone

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CCS Chemistry 2024年第3期6卷 652-662页

作者： Mingkun Gao Guoju Yang Guangyuan He Risheng Bai Jialiang Li Yinghao Liu Qiang Zhang Guangrui Chen donghai mei Jihong Yu State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryInternational Center of Future ScienceJilin UniversityChangchun 130012 School of Materials Science and Engineering Tiangong UniversityTianjin 300387

The production ofγ-valerolactone(GVL)from biomass derivatives levulinic acid(LA)based on acidbase metallic catalysts offers a sustainable pathway to the synthesis of valuable chemicals and ***,the development of efficient metallic catalysts with tunable Lewis acid–base and Brønsted acid sites remains a ***,for the first time,we integrated zeolite and layered double hydroxide(LDH),in a core–shell structure,wherein zeolite and CoFe-LDH provided the Brønsted acidic sites and Lewis acid sites,***,oxygen vacancies(OV_(x))acting as Lewis bases were generated on the surface of LDH via Ga *** efficient cascade catalytic reaction from LA to GVL was successfully achieved over the designed Beta@LDH-OVx catalyst,affording a superior conversion of LA(>99.9%)and an impressive selectivity to GVL(89.18%).Importantly,the“memory effect”of LDH endowed the catalyst with excellent regeneration of metal active *** functional theory calculations revealed that the introduced OVx facilitated the adsorption of carbonyl oxygen in LA and boosted the production of GVL through the synergistic effect of acid/base sites in the composite *** work presents a rational design route for the construction of multifunctional catalysts by coupling zeolites and LDHs for highly selective catalytic conversion of biomass.

关键词： zeolite layered double hydroxide oxygen vacancies biomass γ-valerolactone

社会转型期的中国农村土地冲突分析--现状、类型与趋势

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东南学术 2008年第6期 36-41页

作者：梅东海中国社会科学院农村发展研究所社会问题研究中心访问研究人员

本文从宏观和微观两个角度探讨了农村土地冲突现状、类型和发展趋势。当前农村土地冲突是农村群体性事件焦点,数量庞大;依据冲突主体不同,农村土地冲突可大致分为农户—农户或村—村、农户—村民小组、农民—基层组织及干部、农民—较... 详细信息

本文从宏观和微观两个角度探讨了农村土地冲突现状、类型和发展趋势。当前农村土地冲突是农村群体性事件焦点,数量庞大;依据冲突主体不同,农村土地冲突可大致分为农户—农户或村—村、农户—村民小组、农民—基层组织及干部、农民—较高层政府及其土地主管部门、农民—资本持有者等五类,每类在方式、博弈过程、规模程度、争夺目标、利益诉求和政治特征上均有所差异;未来农村土地冲突将继续呈上升趋势,中西部地区将会更加明显。

关键词：社会冲突土地冲突农民维权

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锦州黑油水化物生成条件及降凝剂抑制影响

石油与天然气化工 1999年第1期28卷 41-42页

作者：樊栓狮郭天民石油大学油气藏流体高压相态及物性研究室

利用本研究室具有国际先进水平的气体水化物实验测定装置对锦州凝析气田黑油在乙二醇抑制剂存在下水化物生成规律进行了初步实验研究，分析了在现场工况下已筛选出的降凝剂对乙二醇抑制水化物生成作用的影响规律。

关键词：黑油水合物抑制剂降凝剂油气集输

Lennard-Jones 纯流体液汽界面的分子动力学模拟

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清华大学学报（自然科学版） 1998年第6期38卷 23-26页

作者：梅东海李以圭陆九芳陈健清华大学化学工程系

在表面张力长程校正公式的基础上，应用正则系综分子动力学模拟方法较为系统地对Ｌｅｎｎａｒｄ－Ｊｏｎｅｓ（ＬＪ）纯流体的液汽平衡及界面性质进行了模拟研究。在温度Ｔ＊＝ｋＢＴ／ε为０．７５～１．２０范围内，分别计算了７个温... 详细信息

在表面张力长程校正公式的基础上，应用正则系综分子动力学模拟方法较为系统地对Ｌｅｎｎａｒｄ－Ｊｏｎｅｓ（ＬＪ）纯流体的液汽平衡及界面性质进行了模拟研究。在温度Ｔ＊＝ｋＢＴ／ε为０．７５～１．２０范围内，分别计算了７个温度条件下ＬＪ纯流体的汽液相共存平衡密度、密度分布、表面张力和界面厚度。研究结果表明：文中得到的ＬＪ纯流体汽液相平衡密度与采用Ｇｉｂｂｓ系综ＭｏｎｔｅＣａｒｌｏ模拟计算结果基本一致；表面张力的模拟计算值与实验数据符合较好；另外，随着温度的升高，流体的表面张力降低而界面厚度变大。

关键词：分子动力学模拟液汽界面 L-J流体

建设国际旅游岛背景下海南城乡一体化模式探讨

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科学发展 2010年第2期 91-99页

作者：张飞方栓喜梅东海中国(海南)改革发展研究院 570208

国际旅游岛是海南发展的大战略。当前,在建设国际旅游岛的背景下,需要整合城乡旅游资源,实现城乡协调发展。本文分析了海南城乡一体化的现实需求和国际旅游岛框架下推进城乡一体化的突出矛盾,在此基础上,提出把经济一体化、社会一体化... 详细信息

国际旅游岛是海南发展的大战略。当前,在建设国际旅游岛的背景下,需要整合城乡旅游资源,实现城乡协调发展。本文分析了海南城乡一体化的现实需求和国际旅游岛框架下推进城乡一体化的突出矛盾,在此基础上,提出把经济一体化、社会一体化、行政一体化作为推进海南城乡一体化的具体思路。

关键词：国际旅游岛海南城乡一体化模式探讨