In the selective hydrogenation of diene (or alkyne) using heterogenized homogeneous catalyst, the high selectivity of monoene formation only appears in a very short time interval. The addition of suitable electron don...In the selective hydrogenation of diene (or alkyne) using heterogenized homogeneous catalyst, the high selectivity of monoene formation only appears in a very short time interval. The addition of suitable electron donors can decrease or even cease the monoene hydrogenation and thereby keep the high monoene selectivity after reaching its maximum.展开更多
Composites incorporating nanoparticles (NPs) within metal-organic frameworks (MOFs) find applications in many different fields.In particular,using MOF layers as molecular sieves built on the NPs could enable selec...Composites incorporating nanoparticles (NPs) within metal-organic frameworks (MOFs) find applications in many different fields.In particular,using MOF layers as molecular sieves built on the NPs could enable selectivity in heterogeneous catalysis.However,such composites typically exhibit low catalytic efficiency,due to the slow diffusion of the reactants in the long and narrow channels of the MOF shell.In order to improve the catalytic efficiency of these systems,here we report the fabrication of NPs incorporated in nanosized MOFs (NPs@nano-MOFs),obtained by reducing the size of the MOF crystals grown around the NPs.The crystal size of the composites was controlled by modulating the nucleation rate of the MOFs during the encapsulation of pre-synthesized and catalytically active NPs;in this way,NPs@MOF crystals smaller than 50 nm were synthesized and subsequently used as highly efficient catalysts.Due to the shorter path from the MOF surface to the active sites,the obtained Pt@nano-MOFs composites showed a higher conversion rate than their larger-sized counterparts in the synthesis of imines via cascade reaction of nitrobenzene and in the hydrogenation of olefins,while retaining the excellent size and shape selectivity associated with the molecular sieving effect of the MOF layer.The present strategy can also be applied to prepare other encapsulated nanostructures combining various types of NPs and nano-MOFs,thus highlighting the broad potential of this approach for developing optimized catalysts with high reactivity and selectivity.展开更多
Mesoporous N-doped carbon supported palladium catalyst Pd@CN0.132 was able to efficiently catalyze unprotected indole to indoline under mild conditions.In the aqueous system,a selectivity of 100% and conversion of 96%...Mesoporous N-doped carbon supported palladium catalyst Pd@CN0.132 was able to efficiently catalyze unprotected indole to indoline under mild conditions.In the aqueous system,a selectivity of 100% and conversion of 96% was achieved under 313 K and atmospheric hydrogen gas.展开更多
文摘In the selective hydrogenation of diene (or alkyne) using heterogenized homogeneous catalyst, the high selectivity of monoene formation only appears in a very short time interval. The addition of suitable electron donors can decrease or even cease the monoene hydrogenation and thereby keep the high monoene selectivity after reaching its maximum.
基金This work was financially supported by the National Natural Science Foundation of China (Nos. 21641005 and 21604038), the Beijing Engineering Center for Hierarchical Catalysts, the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT1205), the Jiangsu Provindal Founds for Natural Science Foundation (No. BK20160975), the Program for Outstanding Young Scholars from the Organization Department of the CPC Central Committee, and the National Basic Research Program of China (973 Program) (Nos. 2014CB932104 and 2015CB932200).
文摘Composites incorporating nanoparticles (NPs) within metal-organic frameworks (MOFs) find applications in many different fields.In particular,using MOF layers as molecular sieves built on the NPs could enable selectivity in heterogeneous catalysis.However,such composites typically exhibit low catalytic efficiency,due to the slow diffusion of the reactants in the long and narrow channels of the MOF shell.In order to improve the catalytic efficiency of these systems,here we report the fabrication of NPs incorporated in nanosized MOFs (NPs@nano-MOFs),obtained by reducing the size of the MOF crystals grown around the NPs.The crystal size of the composites was controlled by modulating the nucleation rate of the MOFs during the encapsulation of pre-synthesized and catalytically active NPs;in this way,NPs@MOF crystals smaller than 50 nm were synthesized and subsequently used as highly efficient catalysts.Due to the shorter path from the MOF surface to the active sites,the obtained Pt@nano-MOFs composites showed a higher conversion rate than their larger-sized counterparts in the synthesis of imines via cascade reaction of nitrobenzene and in the hydrogenation of olefins,while retaining the excellent size and shape selectivity associated with the molecular sieving effect of the MOF layer.The present strategy can also be applied to prepare other encapsulated nanostructures combining various types of NPs and nano-MOFs,thus highlighting the broad potential of this approach for developing optimized catalysts with high reactivity and selectivity.
基金support from the Joint Petroleum and Petrochemical Funds of the National Natural Science Foundation of ChinaChina National Petroleum Corporation (No.U1162124)+4 种基金the Zhejiang Provincial Natural Science Foundation for Distinguished Young Scholars of China (No.LR13B030001)the Specialized Research Fund for the Doctoral Program of Higher Education (No.J20130060)the National Natural Science Foundation of China (No.21206085)Excellent Middle-aged and Young Scientists Research Award Foundation of Shandong Province (No.BS2011CL023)the Fundamental Research Funds for the Central Universities,the Program for Zhejiang Leading Team of S&T Innovation,and the Partner Group Program of Zhejiang University and the Max-Planck Society are greatly appreciated
文摘Mesoporous N-doped carbon supported palladium catalyst Pd@CN0.132 was able to efficiently catalyze unprotected indole to indoline under mild conditions.In the aqueous system,a selectivity of 100% and conversion of 96% was achieved under 313 K and atmospheric hydrogen gas.