Photocatalytic oxidative desulfurization(PODS)over efficient earth-abundant catalysts to obtain clean fuel oil is of great importance for the environmental protection.In this work,a series of Ce-doped MIL-125-NH_(2)ph...Photocatalytic oxidative desulfurization(PODS)over efficient earth-abundant catalysts to obtain clean fuel oil is of great importance for the environmental protection.In this work,a series of Ce-doped MIL-125-NH_(2)photocatalysts were successfully prepared via a simple in-situ doping method and exhibited superior PODS performance of dibenzothiophene(DBT)under mild reaction conditions.The 1.0 mol%Ce/MIL-125-NH_(2)catalyst achieved 100%sulfur removal within 22 min at 30℃ under visible light illumination,which is mainly attributed to the high surface area and the formation of Ce-Ti-oxo clusters due to electronic coupling.The valence transformation of Ce^(4+)/Ce^(3+)and Ti^(4+)/Ti^(3+)redox mediators could not only expose abundant Lewis acid sites,but also promote the separation and transfer of photogenerated charges.In addition,increasing the reaction temperature has been demonstrated to be effective in promoting the PODS performance.Additionally,a thermo-enhanced PODS mechanism was proposed over Ce/MIL-125-NH_(2),demonstrating the great potential of thermal energy to promote the desulfurization activity.展开更多
Efficient hydrogen production via photocatalysis with high utilization efficiency of Pt cocatalyst is of great importance for sustainable development. In this work, we report an in situ auto-reduction strategy to enca...Efficient hydrogen production via photocatalysis with high utilization efficiency of Pt cocatalyst is of great importance for sustainable development. In this work, we report an in situ auto-reduction strategy to encapsulate highly dispersed Pt clusters inside the cages of MIL-125-NH_(2). The amino groups in MIL-125-NH_(2) first react with formaldehyde to form reducing groups (i.e.,–NH-CH_(2)OH), which can in situ auto-reduce the confined Pt^(2+) ions to ultrasmall Pt clusters within the cavities. With optimized Pt content, photocatalytic H_(2) production over the obtained Pt(1.5)/MIL-125-NH-CH_(2)OH catalyst with 1.43 wt.% Pt loading achieved as high as 4,496.4 µmol·g^(-1)·h^(-1) under visible light (λ > 420 nm) due to the facilitated transfer and separation of the photo-induced charger carriers arising from the synergetic effects between highly dispersed Pt clusters and MIL-125-NH-CH_(2)OH framework. This in situ auto-reduction strategy may be extended to encapsulate various kinds of metal or alloy clusters/nanoparticles within amino-functioned metal-organic frameworks (MOFs) with superior properties and excellent performance.展开更多
基金supported by the National Key Research and Development Program of China(No.2021YFB3500700)the National Natural Science Foundation of China(No.21976054)Fundamental Research Funds for the Central Universities(No.FRFTP-20-005A3)。
文摘Photocatalytic oxidative desulfurization(PODS)over efficient earth-abundant catalysts to obtain clean fuel oil is of great importance for the environmental protection.In this work,a series of Ce-doped MIL-125-NH_(2)photocatalysts were successfully prepared via a simple in-situ doping method and exhibited superior PODS performance of dibenzothiophene(DBT)under mild reaction conditions.The 1.0 mol%Ce/MIL-125-NH_(2)catalyst achieved 100%sulfur removal within 22 min at 30℃ under visible light illumination,which is mainly attributed to the high surface area and the formation of Ce-Ti-oxo clusters due to electronic coupling.The valence transformation of Ce^(4+)/Ce^(3+)and Ti^(4+)/Ti^(3+)redox mediators could not only expose abundant Lewis acid sites,but also promote the separation and transfer of photogenerated charges.In addition,increasing the reaction temperature has been demonstrated to be effective in promoting the PODS performance.Additionally,a thermo-enhanced PODS mechanism was proposed over Ce/MIL-125-NH_(2),demonstrating the great potential of thermal energy to promote the desulfurization activity.
基金We acknowledge the financial supports from the National Natural Science Foundation of China(No.51802015)Fundamental Research Funds for the Central Universities(No.FRF-TP-20-005A3)Interdisciplinary Research Project for Young Teachers of USTB(Fundamental Research Funds for the Central Universities)(No.FRF-IDRY-19-020).
文摘Efficient hydrogen production via photocatalysis with high utilization efficiency of Pt cocatalyst is of great importance for sustainable development. In this work, we report an in situ auto-reduction strategy to encapsulate highly dispersed Pt clusters inside the cages of MIL-125-NH_(2). The amino groups in MIL-125-NH_(2) first react with formaldehyde to form reducing groups (i.e.,–NH-CH_(2)OH), which can in situ auto-reduce the confined Pt^(2+) ions to ultrasmall Pt clusters within the cavities. With optimized Pt content, photocatalytic H_(2) production over the obtained Pt(1.5)/MIL-125-NH-CH_(2)OH catalyst with 1.43 wt.% Pt loading achieved as high as 4,496.4 µmol·g^(-1)·h^(-1) under visible light (λ > 420 nm) due to the facilitated transfer and separation of the photo-induced charger carriers arising from the synergetic effects between highly dispersed Pt clusters and MIL-125-NH-CH_(2)OH framework. This in situ auto-reduction strategy may be extended to encapsulate various kinds of metal or alloy clusters/nanoparticles within amino-functioned metal-organic frameworks (MOFs) with superior properties and excellent performance.
文摘寻找具有高效、高吸附量、高选择性的吸附剂处理放射性的含铀废水,对环境保护具有现实意义.通过溶剂热法合成两种金属有机框架材料MIL-125和NH2-MIL-125,并用X-射线衍射仪(XRD)、扫描电镜(SEM)、傅里叶变换红外光谱仪(FT-IR)、热重分析仪(TGA/DSC)等仪器对两种材料的结构和形貌分别进行表征,探究不同的初始pH、初始铀浓度、吸附时间等条件下两种材料分别对UO2^2+吸附性能的影响.结果表明:本实验成功合成了MIL-125和NH2-MIL-125两种材料;当初始pH分别为5和8时,MIL-125和NH2-MIL-125材料对UO2^2+的吸附效果最好.通过Langmuir和Freundlich方程进行热力学拟合可知,两种材料的吸附过程更符合Langmuir方程,在25℃时MIL-125、NH2-MIL-125对UO2^2+的最大吸附量分别为264.4 mg·g^-1和327.3 mg·g^-1,最佳吸附时间分别为480 min和70 min.
