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As(V)在TiO2表面的吸附机理 被引量:7
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作者 张美一 何广智 +2 位作者 丁程程 陈灏 潘纲 《物理化学学报》 SCIE CAS CSCD 北大核心 2009年第10期2034-2038,共5页
用延展X射线吸收精细结构(EXAFS)光谱和密度泛函理论(DFT)研究了As(V)-TiO2体系的吸附机理.离子强度变化对As(V)-TiO2体系吸附无显著影响,表明吸附后形成了内层络合物.EXAFS结果表明,As(V)原子主要通过—AsO4上的O原子结合到TiO2表面上... 用延展X射线吸收精细结构(EXAFS)光谱和密度泛函理论(DFT)研究了As(V)-TiO2体系的吸附机理.离子强度变化对As(V)-TiO2体系吸附无显著影响,表明吸附后形成了内层络合物.EXAFS结果表明,As(V)原子主要通过—AsO4上的O原子结合到TiO2表面上,平均As-O原子间距(R)在吸附前后无明显变化,保持在(0.169±0.001)nm.As-Ti层的EXAFS分析结果与DFT计算的吸附构型的As-Ti原子间距对照表明,体系存在两种主要亚稳平衡吸附(MEA)结构,即对应于R1=(0.321±0.002)nm的双角(DC)强吸附构型和R2=(0.360±0.002)nm的单角(SC)弱吸附构型.而且随着吸附量由9.79mg·g-1增加至28.0mg·g-1,吸附样品中双角构型配位数与单角构型配位数的比值(CN1/CN2)从3.3降低到1.6,说明双角亚稳平衡吸附结构在低覆盖度时占优势,而在高表面覆盖度时单角亚稳平衡吸附结构占优势,即在表面覆盖度较大时,As(V)在TiO2表面上倾向于形成单角构型. 展开更多
关键词 TIO2 AS(V) 吸附 延展X射线吸收精细结 密度泛函理论 微观吸附构型
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Development of a pentaethylenehexamine-modified solid support adsorbent for CO_2 capture from model flue gas 被引量:5
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作者 韦力 靖宇 +1 位作者 高正明 王运东 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2015年第2期366-371,共6页
A novel solid support adsorbent for CO2capture was developed by loading pentaethylenehexamine(PEHA)on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method.MCM-41 samples before and af... A novel solid support adsorbent for CO2capture was developed by loading pentaethylenehexamine(PEHA)on commercially available mesoporous molecular sieve MCM-41 using wet impregnation method.MCM-41 samples before and after PEHA loading were characterized by X-ray powder diffraction,N2adsorption/desorption,thermal gravimetric analysis and scanning electron microscope to investigate the textural and thermo-physical properties.CO2adsorption performance was evaluated in a fixed bed adsorption system.Results indicated that the structure of MCM-41 was preserved after loading PEHA.Surface area and total pore volume of PEHA loaded MCM-41 decreased with the increase of loading.The working adsorption capacity of CO2could be significantly improved at 60%of PEHA loading and 75°C.The effect of the height of adsorbent bed was investigated and the best working adsorption capacity for MCM-41-PEHA-60 reached 165 mg·(g adsorbent)-1at 75°C.Adsorption/desorption circle showed that the CO2working adsorption capacity of MCM-41-PEHA kept stable. 展开更多
关键词 CO2adsorption Pentaethylenehexamine MCM-41 molecular sieve CO2adsorbent
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