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
In the preparation of catalyst for propylene polymerization, the Mg(OEt) 2 support was activated with ethanol/CO 2 system followed by solidification, and treated with TiCl 4 in the presence of ethylbenzoate as an inte...In the preparation of catalyst for propylene polymerization, the Mg(OEt) 2 support was activated with ethanol/CO 2 system followed by solidification, and treated with TiCl 4 in the presence of ethylbenzoate as an internal donor(ID). The chemical compositions of the activated support and the prepared catalyst were examined in detail. During the dissolution of Mg(OEt) 2 support in ethanol medium with CO 2 bubbling, the structure of support changed to magnesium hydrocarbyl carbonate, (CH 3CH 2O) 2- x Mg(O (C O) OCH 2CH 3) x ( x = 1,2). The content of carbonated CO 2 in the activated support was dependent on the heat treatment in the solidification of support. In the preparation procedure of polymerization catalyst, the activated support was treated with TiCl 4 so that the structure of support was converted to MgCl 2 with the incorporation of ID. The polymerization behavior of the pre-pared catalyst was also studied in the presence of phenyltriethoxysilane as an external donor.展开更多
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.
文摘In the preparation of catalyst for propylene polymerization, the Mg(OEt) 2 support was activated with ethanol/CO 2 system followed by solidification, and treated with TiCl 4 in the presence of ethylbenzoate as an internal donor(ID). The chemical compositions of the activated support and the prepared catalyst were examined in detail. During the dissolution of Mg(OEt) 2 support in ethanol medium with CO 2 bubbling, the structure of support changed to magnesium hydrocarbyl carbonate, (CH 3CH 2O) 2- x Mg(O (C O) OCH 2CH 3) x ( x = 1,2). The content of carbonated CO 2 in the activated support was dependent on the heat treatment in the solidification of support. In the preparation procedure of polymerization catalyst, the activated support was treated with TiCl 4 so that the structure of support was converted to MgCl 2 with the incorporation of ID. The polymerization behavior of the pre-pared catalyst was also studied in the presence of phenyltriethoxysilane as an external donor.
