以正硅酸乙酯为硅源,合成了具有MFI结构的球形和六方片状silicalite-1全硅分子筛,并将其作为载体制备了负载型催化剂用于丙烷脱氢制丙烯反应;采用SEM、XRD、TEM、N_(2)吸附-脱附、Py-FTIR、NH_(3)-TPD、^(29)Si MAS NMR和H_(2)-TPR等方...以正硅酸乙酯为硅源,合成了具有MFI结构的球形和六方片状silicalite-1全硅分子筛,并将其作为载体制备了负载型催化剂用于丙烷脱氢制丙烯反应;采用SEM、XRD、TEM、N_(2)吸附-脱附、Py-FTIR、NH_(3)-TPD、^(29)Si MAS NMR和H_(2)-TPR等方法对两种分子筛载体及负载型催化剂的结构和表面性质进行表征,研究了不同形貌silicalite-1载体对催化剂性能的影响机制。实验结果表明,球形silicalite-1分子筛载体具有更大的外比表面积和更多的表面硅羟基,进而增强了活性组分与载体间的相互作用,提高了活性金属在载体表面的分散度,因此在丙烷脱氢制丙烯反应中球形silicalite-1载体负载的催化剂具有更高的活性。展开更多
Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional therm...Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs.展开更多
文摘以正硅酸乙酯为硅源,合成了具有MFI结构的球形和六方片状silicalite-1全硅分子筛,并将其作为载体制备了负载型催化剂用于丙烷脱氢制丙烯反应;采用SEM、XRD、TEM、N_(2)吸附-脱附、Py-FTIR、NH_(3)-TPD、^(29)Si MAS NMR和H_(2)-TPR等方法对两种分子筛载体及负载型催化剂的结构和表面性质进行表征,研究了不同形貌silicalite-1载体对催化剂性能的影响机制。实验结果表明,球形silicalite-1分子筛载体具有更大的外比表面积和更多的表面硅羟基,进而增强了活性组分与载体间的相互作用,提高了活性金属在载体表面的分散度,因此在丙烷脱氢制丙烯反应中球形silicalite-1载体负载的催化剂具有更高的活性。
基金the“National Natural Science Foundation of China(No.22122202)”.
文摘Inducing the classic strong metal-support interaction(SMSI)is an effective approach to enhance the performance of supported metal catalysts by encapsulating the metal nanoparticles(NPs)with supports.Conventional thermal reduction method for inducing SMSI processes is often accompanied by undesirable structural evolution of metal NPs.In this study,a mild electrochemical method has been developed as a new approach to induce SMSI,using the cable structured core@shell CNT@SnO_(2) loaded Pt NPs as a proof of concept.The induced SnO_(x) encapsulation layer on the surface of Pt NPs can protect Pt NPs from the poisoned of CO impurity in hydrogen oxidation reaction(HOR),and the HOR current density could still maintain 85% for 2000 s with 10,000 ppm CO in H_(2),while the commercial Pt/C is completely inactivated.In addition,the electrons transfer from SnO_(x) to Pt NPs improved the HOR activity of the E-Pt-CNT@SnO_(2),achieving the excellent exchange current density of 1.55 A·mgPt^(-1).In situ Raman spectra and theoretical calculations show that the key to the electrochemical-method-induced SMSI is the formation of defects and the migration of SnO_(x) caused by the electrochemical redox operation,and the weakening the SneO bond strength by Pt NPs.
