To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content ...To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.展开更多
采用高温固相法制备了SrZrSi_(2)O_(7):Ce^(3+),Mn^(2+)荧光粉。通过X射线衍射(X-ray Power Diffractometer,XRD)、激发和发射光谱及电子显微分析对材料的分子结构、显微形貌、发光特性和能量传递机理进行了研究。结果表明,荧光粉的主...采用高温固相法制备了SrZrSi_(2)O_(7):Ce^(3+),Mn^(2+)荧光粉。通过X射线衍射(X-ray Power Diffractometer,XRD)、激发和发射光谱及电子显微分析对材料的分子结构、显微形貌、发光特性和能量传递机理进行了研究。结果表明,荧光粉的主晶相是单斜晶系的SrZrSi_(2)O_(7),Ce^(3+)离子和Mn^(2+)离子占据一部分Sr^(2+)离子的晶体学格位。在296 nm激发下,可以观察到来自Ce^(3+)离子的蓝光发射峰,归属于Ce^(3+)离子的5d→4f能级跃迁。在544 nm处,有来自Mn^(2+)离子的绿光发射峰,归因于Mn^(2+)离子的^(4)T_(1)(4G)-^(6)A_(1)(6S)自旋禁止跃迁,表明发生了从Ce^(3+)离子到Mn^(2+)离子的能量传递过程,为设计蓝光到绿光之间可控制备的新型荧光粉提供了理论和实验的信息。展开更多
基金Supported by the Science and Technology Cooperation and Exchange special project of Cooperation of Shanxi Province(202404041101014)the Fundamental Research Program of Shanxi Province(202403021212333)+3 种基金the Joint Funds of the National Natural Science Foundation of China(U24A20555)the Lvliang Key R&D of University-Local Cooperation(2023XDHZ10)the Initiation Fund for Doctoral Research of Taiyuan University of Science and Technology(20242026)the Outstanding Doctor Funding Award of Shanxi Province(20242080).
文摘To elucidate the effect of calcite-regulated activated carbon(AC)structure on low-temperature denitrification performance of SCR catalysts,this work prepared a series of Mn-Ce/De-AC-xCaCO_(3)(x is the calcite content in coal)catalysts were prepared by the incipient wetness impregnation method,followed by acid washing to remove calcium-containing minerals.Comprehensive characterization and low-temperature denitrification tests revealed that calcite-induced structural modulation of coal-derived AC significantly enhances catalytic activity.Specifically,NO conversion increased from 88.3%of Mn-Ce/De-AC to 91.7%of Mn-Ce/De-AC-1CaCO_(3)(210℃).The improved SCR denitrification activity results from the enhancement of physicochemical properties including higher Mn^(4+)content and Ce^(4+)/Ce^(3+)ratio,an abundance of chemisorbed oxygen and acidic sites,which could strengthen the SCR reaction pathways(richer NH_(3)activated species and bidentate nitrate active species).Therefore,NO removal is enhanced.
文摘采用高温固相法制备了SrZrSi_(2)O_(7):Ce^(3+),Mn^(2+)荧光粉。通过X射线衍射(X-ray Power Diffractometer,XRD)、激发和发射光谱及电子显微分析对材料的分子结构、显微形貌、发光特性和能量传递机理进行了研究。结果表明,荧光粉的主晶相是单斜晶系的SrZrSi_(2)O_(7),Ce^(3+)离子和Mn^(2+)离子占据一部分Sr^(2+)离子的晶体学格位。在296 nm激发下,可以观察到来自Ce^(3+)离子的蓝光发射峰,归属于Ce^(3+)离子的5d→4f能级跃迁。在544 nm处,有来自Mn^(2+)离子的绿光发射峰,归因于Mn^(2+)离子的^(4)T_(1)(4G)-^(6)A_(1)(6S)自旋禁止跃迁,表明发生了从Ce^(3+)离子到Mn^(2+)离子的能量传递过程,为设计蓝光到绿光之间可控制备的新型荧光粉提供了理论和实验的信息。
