A 2 D-2 D titanium dioxide nanosheet-reduced graphene oxide(TNS-r GO)composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal method.The as-obtained TNS-r GO composite was furt...A 2 D-2 D titanium dioxide nanosheet-reduced graphene oxide(TNS-r GO)composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal method.The as-obtained TNS-r GO composite was further functionalized with 3-aminopropyltriethoxysilane(APTES)to provide a large amount of-NH2 groups on the surface for anchoring ultrafine Pd Ag alloy nanoparticles with an average particle size of 1.69 nm by a facile wet reduction approach.Benefiting from the combined effects of well-dispersed Pd Ag alloy nanoparticles,facilitated electron transfer from TNS-r GO to Pd,and increased electron density of active sites,the Pd8 Ag_(1)/NH_(2)-TNS-r GO catalyst exhibited excellent activity towards dehydrogenation of formic acid without adding any additives at 298 K,corresponding to an initial turn over frequency as high as 1090 h-1,which is much higher than that of most other state-of-theart catalysts.展开更多
Nano structure including pore structure and amine assembly is critical for improving sorption and desorption kinetics for adsorptive CO_(2) separation.The present work delineates(1)the influence of the nano-scale pore...Nano structure including pore structure and amine assembly is critical for improving sorption and desorption kinetics for adsorptive CO_(2) separation.The present work delineates(1)the influence of the nano-scale pore structure of amine-functionalized solid sorbents,and(2)effect of changing the assembly of amine molecules on surface of nano-porous SiO_(2) on the rates of adsorption and desorption of CO_(2).50PEI-MSN sorbent with inverted cone-shaped pores was prepared by using mesoporous silica nanospheres(MSN)with inverted cone-shaped pores for the loading of polyethyleneimine(PEI).Co-structure-directing(CSD)method was used to synthesize the sorbent with arranged amine assembly at nano-scale(2N-CSD).By comparison with 50PE卜SBA15 as a benchmark sorbent,both sorbents have improved sorption and desorption kinetics.There are significant effects of nano pore structure and amine assembly on the sorption and desorption kinetics.The inverted cone-shaped pores in MSN allow loading polymeric amines in their narrower ends and leaving larger pore mouths open for the transport of CO_(2);50PEI-MSN shows a maximum sorption rate of 81.4 mg·g^(-1)·min^(-1) with average sorption rate of 25.4mg·g^(-1)·min^(-1) at 80℃ which are 34%and 59%higher than the corresponding values for 50PEI-SBA15;a maximum desorption rate of 38.4mg·g^(-1)·min^(-1) with average desorption rate of 11.8 mg·g^(-1)·min^(-1) ramping from 30 to 95℃ which are 37%and 156%higher than the corresponding values for 50PEI-SBA15.The arranged monolayer-like amine assembly on surface of nanoporous SiO_(2) likely provides high amine sorption sites through improved accessibility of amine,and 2N-CSD shows a maximum sorption rate of 60.5 mg·g^(-1)·min^(-1),with average sorption rate of 12.8mg·g^(-1)·min^(-1) at 300C which are 108%and 205%higher than the corresponding values for 50PEI-SBA15;a lower maximum desorption rate of 9.7 mg g'1min"1 and average desorption rate of 9.8mg·g^(-1)·min^(-1) ramping from 30 to 95℃ which is 250%higher than the correspondi展开更多
In the work,we propose an efficient one-pot approach for synthesis of a new type of mesoporous silica nanoparticles(MSNs).That can be successfully realized by using tetraethylorthosilicate(TEOS) and N-[3-(trimethoxysi...In the work,we propose an efficient one-pot approach for synthesis of a new type of mesoporous silica nanoparticles(MSNs).That can be successfully realized by using tetraethylorthosilicate(TEOS) and N-[3-(trimethoxysilyl)propyl]ethylenediamine(TSD) as the silica precursors and cetyltrimethylammonium bromide(CTAB) as the structure-directing agent through a facile assembly process.The as-synthesized MSNs possess a spherical morphology with about 230 nm,a relatively high surface area of133 m^2/g,and a hierarchical pore size distribution.When applied as the sorbents,the amine-functioned MSNs demonstrate the enhanced adsorption capacity for CO2 capture(at 1 bar,15 vol% CO2,up to80.5 mg/g at 75℃),high selectivity,and good cycling durability,benefiting from the suitable modification of polyethyleneimine.展开更多
3-Aminopropyltriethoxysilane functionalized worm-like mesoporous silica monolithic（WMSM-NH2） was prepared and used as a new regenerable adsorbent for the removal of Cu2＋ ions. The analysis results show that the WMS...3-Aminopropyltriethoxysilane functionalized worm-like mesoporous silica monolithic（WMSM-NH2） was prepared and used as a new regenerable adsorbent for the removal of Cu2＋ ions. The analysis results show that the WMSM-NH2 monolithic had a high efficiency value of 99.3% for Cu2＋ remediation when the Cu2＋ solution was at an initial concentration of 10.32 mg/L. The regeneration study of the WMSM-NH2 monolithic presented that the adsorp- tion efficiency of 89.0% was remained and a mass of 92.0% was left after seven adsorption-desorption cycles were executed. The monolithic material with high resistance to the acid and good mechanical stability can facilitate the operations of adsorption and regeneration of the adsorbent.展开更多
基金the financial supports from the Shandong Provincial Natural Science Foundation(Grant No.ZR201910220216)the Key Research and Development Plan of Shandong Province(2019GGX104034)+1 种基金the Foundation of State Key Laboratory of High-efficiency Utilization of Coal,and Green Chemical Engineering(Grant No.2020-KF-18)the Taishan Scholar Program of Shandong Province(No.ts201712045)。
文摘A 2 D-2 D titanium dioxide nanosheet-reduced graphene oxide(TNS-r GO)composite with better electronic conductivity and hydrophilicity was prepared by the hydrothermal method.The as-obtained TNS-r GO composite was further functionalized with 3-aminopropyltriethoxysilane(APTES)to provide a large amount of-NH2 groups on the surface for anchoring ultrafine Pd Ag alloy nanoparticles with an average particle size of 1.69 nm by a facile wet reduction approach.Benefiting from the combined effects of well-dispersed Pd Ag alloy nanoparticles,facilitated electron transfer from TNS-r GO to Pd,and increased electron density of active sites,the Pd8 Ag_(1)/NH_(2)-TNS-r GO catalyst exhibited excellent activity towards dehydrogenation of formic acid without adding any additives at 298 K,corresponding to an initial turn over frequency as high as 1090 h-1,which is much higher than that of most other state-of-theart catalysts.
基金supported by the National Natural Science Foundation of China(21373035)Fundamental Research Funds for the Central Universities in China(DUT13YQ107)~~
基金financially supported by the National Key Research and Development Program of China(No.2016YFB0600902-4)the Fundamental Research Funds for the Central Universities(No.DUT20RC(5)002)the CUHK Research Startup Fund(No.#4930981).
文摘Nano structure including pore structure and amine assembly is critical for improving sorption and desorption kinetics for adsorptive CO_(2) separation.The present work delineates(1)the influence of the nano-scale pore structure of amine-functionalized solid sorbents,and(2)effect of changing the assembly of amine molecules on surface of nano-porous SiO_(2) on the rates of adsorption and desorption of CO_(2).50PEI-MSN sorbent with inverted cone-shaped pores was prepared by using mesoporous silica nanospheres(MSN)with inverted cone-shaped pores for the loading of polyethyleneimine(PEI).Co-structure-directing(CSD)method was used to synthesize the sorbent with arranged amine assembly at nano-scale(2N-CSD).By comparison with 50PE卜SBA15 as a benchmark sorbent,both sorbents have improved sorption and desorption kinetics.There are significant effects of nano pore structure and amine assembly on the sorption and desorption kinetics.The inverted cone-shaped pores in MSN allow loading polymeric amines in their narrower ends and leaving larger pore mouths open for the transport of CO_(2);50PEI-MSN shows a maximum sorption rate of 81.4 mg·g^(-1)·min^(-1) with average sorption rate of 25.4mg·g^(-1)·min^(-1) at 80℃ which are 34%and 59%higher than the corresponding values for 50PEI-SBA15;a maximum desorption rate of 38.4mg·g^(-1)·min^(-1) with average desorption rate of 11.8 mg·g^(-1)·min^(-1) ramping from 30 to 95℃ which are 37%and 156%higher than the corresponding values for 50PEI-SBA15.The arranged monolayer-like amine assembly on surface of nanoporous SiO_(2) likely provides high amine sorption sites through improved accessibility of amine,and 2N-CSD shows a maximum sorption rate of 60.5 mg·g^(-1)·min^(-1),with average sorption rate of 12.8mg·g^(-1)·min^(-1) at 300C which are 108%and 205%higher than the corresponding values for 50PEI-SBA15;a lower maximum desorption rate of 9.7 mg g'1min"1 and average desorption rate of 9.8mg·g^(-1)·min^(-1) ramping from 30 to 95℃ which is 250%higher than the correspondi
基金support from the Shanghai Pujiang Program (No.17PJD015)Shuguang Program supported by Shanghai Education Development Foundation and Shanghai Municipal Education Commission (No.18SG035)
文摘In the work,we propose an efficient one-pot approach for synthesis of a new type of mesoporous silica nanoparticles(MSNs).That can be successfully realized by using tetraethylorthosilicate(TEOS) and N-[3-(trimethoxysilyl)propyl]ethylenediamine(TSD) as the silica precursors and cetyltrimethylammonium bromide(CTAB) as the structure-directing agent through a facile assembly process.The as-synthesized MSNs possess a spherical morphology with about 230 nm,a relatively high surface area of133 m^2/g,and a hierarchical pore size distribution.When applied as the sorbents,the amine-functioned MSNs demonstrate the enhanced adsorption capacity for CO2 capture(at 1 bar,15 vol% CO2,up to80.5 mg/g at 75℃),high selectivity,and good cycling durability,benefiting from the suitable modification of polyethyleneimine.
基金Supported by the National Natural Science Foundation of China（Nos. 50573030 and 21171065）.
文摘3-Aminopropyltriethoxysilane functionalized worm-like mesoporous silica monolithic（WMSM-NH2） was prepared and used as a new regenerable adsorbent for the removal of Cu2＋ ions. The analysis results show that the WMSM-NH2 monolithic had a high efficiency value of 99.3% for Cu2＋ remediation when the Cu2＋ solution was at an initial concentration of 10.32 mg/L. The regeneration study of the WMSM-NH2 monolithic presented that the adsorp- tion efficiency of 89.0% was remained and a mass of 92.0% was left after seven adsorption-desorption cycles were executed. The monolithic material with high resistance to the acid and good mechanical stability can facilitate the operations of adsorption and regeneration of the adsorbent.
