Flower-like tin oxide-supported platinum（Pt/SnOx） with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-li...Flower-like tin oxide-supported platinum（Pt/SnOx） with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles（NPs） of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde（HCHO） at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt（Pt/g-SnOx）,and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.展开更多
Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial struct...Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial structures with large pore channels and their excellent biocompatibility.In this review,we review the recent progress in research on enzyme immobilization using DMSNs with different structures,namely,flower-like DMSNs and tree-branch-like DMSNs.Three DMSN synthesis methods are briefly compared,and the distinct characteristics of the two DMSN types and their effects on the catalytic performance of immobilized enzymes are comprehensively discussed.Possible directions for future research on enzyme immobilization using DMSNs are also proposed.展开更多
基金supported by the National Natural Science Foundation of China (51320105001, 51372190, 21573170, 51272199, 21433007)the National Basic Research Program of China (973 program, 2013CB632402)+2 种基金the Natural Science Foundation of Hubei Province (2015CFA001)the Fundamental Research Funds for the Central Universities (WUT: 2015-Ⅲ-034)Innovative Research Funds of SKLWUT (2015-ZD-1)~~
文摘Flower-like tin oxide-supported platinum（Pt/SnOx） with a hierarchical structure was synthesized by a hydrothermal method and characterized by XRD,SEM,TEM,high resolution TEM,XPS and nitrogen adsorption.The flower-like Pt/SnOx microspheres of 1 μm in diameter were composed of staggered petal-like nanosheets with a thickness of 20 nm.Pt nanoparticles（NPs） of 2-3 nm were well dispersed on the SnOx nanosheets.The catalyst was tested in the catalytic oxidation of gaseous formaldehyde（HCHO） at room temperature,and exhibited enhanced activity compared to Pt NPs supported on commercial SnO and ground SnOx.HCHO removal of 87%was achieved over the hierarchical Pt/SnOx after 1 h of reaction,which was 1.5 times that over the ground SnOx-supported Pt（Pt/g-SnOx）,and the high activity was maintained after six recycles,showing the high stability of this catalyst.HCHO decomposition kinetics was modeled as a second order reaction.The reaction rate constant for Pt/SnOx was 5.6 times higher than Pt/g-SnOx.The hierarchical pore structure was beneficial for the diffusion and adsorption of HCHO molecules,and the highly dispersed Pt NPs on the SnOx nanosheets were the active sites for the oxidative decomposition of HCHO into CO2 and H2O.This study provided a promising approach for designing efficient catalysts for indoor HCHO removal at ambient temperature.
基金supported by the National Natural Science Foundation of China(No.22178083)the Natural Science Foundation of Hebei Province(C2019208174 and B2022202014)+1 种基金the S&T Program of Hebei(20372802D,21372804D,and 21372805D)the Natural Science Foundation of Tianjin City(20JCYBJC00530)
文摘Dendritic mesoporous silica nanoparticles(DMSNs)are a new class of solid porous materials used for enzyme immobilization support due to their intrinsic characteristics,including their unique open central-radial structures with large pore channels and their excellent biocompatibility.In this review,we review the recent progress in research on enzyme immobilization using DMSNs with different structures,namely,flower-like DMSNs and tree-branch-like DMSNs.Three DMSN synthesis methods are briefly compared,and the distinct characteristics of the two DMSN types and their effects on the catalytic performance of immobilized enzymes are comprehensively discussed.Possible directions for future research on enzyme immobilization using DMSNs are also proposed.
