This paper reviews the recent achievements in the immobilization of metal nanoparticles on ion-exchange resins and the related catalytic application. The focus is on the production processes for fine and commodity che...This paper reviews the recent achievements in the immobilization of metal nanoparticles on ion-exchange resins and the related catalytic application. The focus is on the production processes for fine and commodity chemicals for which a low environmental impact has been demonstrated. The most significant papers that appeared in the literature from January 2010 to July 2014 have been covered. Their uses in unselective processes, bulk chemicals production, fuel cells components, as well as the use of metal-free ion-exchange resins in acid / base-catalysed reactions, were not included.展开更多
Palladium based catalysts are the most active for methane oxidation. The tuning of their composition, structure and morphology at macro and nanoscale can alter significantly their catalytic behavior and robustness wit...Palladium based catalysts are the most active for methane oxidation. The tuning of their composition, structure and morphology at macro and nanoscale can alter significantly their catalytic behavior and robustness with a strong impact on their overall performances. Among the several combinations of supports and promoters that have been utilized, Pd/CeO2 has attracted a great attention due to its activity and durability coupled with the unusually high degree of interaction between Pd/Pd O and the support. This allows the creation of specific structural arrangements which profoundly impact on methane activation characteristics. Here we want to review the latest findings in this area, and particularly to envisage how the control(when possible) of Pd-CeO2 interaction at nanoscale can help in designing more robust methane oxidation catalysts.展开更多
Few layer graphene （FLG）, multi-walled carbon nanotubes （CNTs） and a nanotube-graphene composite （CNT-FLG） were used as supports for palladium nanoparticles. The catalysts, which were characterized by transmissi...Few layer graphene （FLG）, multi-walled carbon nanotubes （CNTs） and a nanotube-graphene composite （CNT-FLG） were used as supports for palladium nanoparticles. The catalysts, which were characterized by transmission electron microscopy, Raman spectroscopy and X-ray diffraction, were used as anodes in the electrooxidation of ethanol, ethylene glycol and glycerol in half cells and in passive direct ethanol fuel cells. Upon Pd deposition, a stronger interaction was found to occur between the metal and the nanotube-graphene composite and the particle size was significantly smaller in this material （6.3 nm）, comparing with nanotubes and graphene alone （8 and 8.4 nm, respectively）. Cyclic voltammetry experiments conducted with Pd/CNT, Pd/FLG and Pd/CNT-FLG in 10 wt% ethanol and 2 M KOH solution, showed high specific currents of 1.48, 2.29 and 2.51 mA-/zgp-d, respectively. Moreover, the results obtained for ethylene glycol and glycerol oxidation highlighted the excellent electrocatalytic activity of Pd/CNT-FLG in terms of peak current density （up to 3.70 mAgd for ethylene glycol and 1.84 mAfor glycerol, respectively）. Accordingly, Pd/CNT-FLG can be considered as the best performing one among the electrocatalysts ever reported for ethylene glycol oxidation, especially considering the low metal loading used in this work. Direct ethanol fuel cells at room temperature were studied by obtaining power density curves and undertaking galvanostatic experiments. The power density outputs using Pd/CNT, Pd/FLG and Pd/CNT-FLG were 12.1, 16.3 and 18.4 mW.cm-2, respectively. A remarkable activity for ethanol electrooxidation was shown by Pd/CNT-FLG anode catalyst. In a constant current experiment, the direct ethanol fuel cell containing Pd/CNT-FLG could continuously deliver 20 mA.cm-2 for 9.5 h during the conversion of ethanol into acetate of 30%, and the energy released from the cell was about 574 J.展开更多
Hydrogen production via water electrolysis defines the novel energy vector for achieving a sustainable society.However,the true progress of the given technology is hindered by the sluggish and complex hydrogen evoluti...Hydrogen production via water electrolysis defines the novel energy vector for achieving a sustainable society.However,the true progress of the given technology is hindered by the sluggish and complex hydrogen evolution reaction(HER)occurring at the cathodic side of the system where overpriced and scarce Pt-based electrocatalysts are usually employed.Therefore,efficient platinum group metals(PGMs)-free electrocatalysts to carry out HER with accelerated kinetics are urgently demanded.In this scenario,molybdenum disulfide(MoS_(2))owing to efficacious structural attributes and optimum hydrogen-binding free energy(ΔG_(H*))is emerging as a reliable alternative to PGMs.However,the performance of MoS_(2)-based electrocatalysts is still far away from the benchmark performance.The HER activity of MoS_(2)can be improved by engineering the structural parameters i.e.,doping,defects inducement,modulating the electronic structure,stabilizing the 1 T phase,creating nanocomposites,and altering the morphologies using appropriate fabrication pathways.Here,we have comprehensively reviewed the majority of the scientific endeavors published in recent years to uplift the HER activity of MoS_(2)-based electrocatalysts using different methods.Advancements in the major fabrication strategies including hydrothermal synthesis methods,chemical vapor deposition,exfoliation techniques,plasma treatments,chemical methodologies,etc.to tune the structural parameters and hence their ultimate influence on the electrocatalytic activity in acidic and/or alkaline media have been thoroughly discussed.This study can provide encyclopedic insights about the fabrication routes that have been pursued to improve the HER performance of MoS_(2)-based electrocatalysts.展开更多
1 Results The development of the concepts of nanotechnology has given an important impact on the design of new polymer based materials which are in most cases characterized by a multiphase morphology. When at least on...1 Results The development of the concepts of nanotechnology has given an important impact on the design of new polymer based materials which are in most cases characterized by a multiphase morphology. When at least one phase has nanometric dimension(s) the system can be considered as a nanocomposite where the interface is not only determining for the adhesion but also may play a role in some bulk properties. Indeed in nanostructured multiphase solids the interface is significant as a bulk component. The...展开更多
Hydrocarbons separation in petrochemical industries is a key,energy-consuming stage in the manufacture of high-quality added-value products—hence the need for more efficient materials and environmentally friendly met...Hydrocarbons separation in petrochemical industries is a key,energy-consuming stage in the manufacture of high-quality added-value products—hence the need for more efficient materials and environmentally friendly methodologies to improve this process.In this context,we have studied the effect of metal-organic frameworks(MOFs)pore functionalization in hexane isomers separation,isolating the robust isoreticular zinc(ll)bipyrazolates Zn(BPZ),showing no pore decoration,Zn(Me_(2)BPZ),the pores of which are decorated with apolar methyl groups,and Zn(BPZ(NH_(2))_(2)),the spacers of which possess polar Lewis-basic functions(H_(2)BPZ=1H,1'H-4,4'-bipyrazole;H_(2)Me_(2)BPZ=3,3'-dimethyl-1H,1'H-4,4'-bipyrazole;H_(2)BPZ(NH_(2))_(2)=3,5-diamino-1H,1'H-4,4'-bipyrazole;DMF=dimethylformamide).After characterizing Zn(BPZ(NH_(2))_(2))as per its crystal structure and thermal behaviour,and all the three MOFs as per their textural properties,we investigated,from the experimental and computational points of view,the impact of the square one-dimensional channels decoration on the separation of the hexane isomers,demonstrating the relevance of pore constrictions in the resolution of the title alkanes mixture.展开更多
The rational design of complex nanostructures is of paramount importance to gain control over their chemical and physical properties.Recently,magnetic-plasmonic heterostructured nanocrystals have been recognized as ke...The rational design of complex nanostructures is of paramount importance to gain control over their chemical and physical properties.Recently,magnetic-plasmonic heterostructured nanocrystals have been recognized as key players in nanomedicine as multifunctional therapeutic-diagnostic tools and in catalysis.Here we show how the properties of gold-iron oxide heterostructured nanocrystals can be tuned by chemical doping of the magnetic subunit.The divalent cations in the iron oxide were substituted with cobalt and manganese to obtain a general formula Au-MFe2O4(M=Fe,Co,Mn).Magnetic properties of the heterostructures could be tuned,while maintaining well-defined plasmon resonance signatures,confirming the dual magnetic-plasmonic functional capability of these nanostructures.展开更多
A frontier topic in nanotechnology is the realization of multifunctional nanoparticles （NPs） via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nano...A frontier topic in nanotechnology is the realization of multifunctional nanoparticles （NPs） via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine, and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here, we describe the synthesis of Fe-doped Ag NPs via laser ablation in liquid solution, bypassing thermodynamics constraints. These NPs have an innovative structure consisting of a scaffold of face-centered cubic metal Ag alternating with disordered Ag-Fe alloy domains, all arranged in a truffle-like morphology. The Fe-Ag NPs exhibit the plasmonic properties of Ag and the magnetic response of Fe-containing phases, and the surface of the Fe-Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe-Ag NPs, the magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept surface-enhanced Raman scattering and photothermal heating experiments. The synthetic approach is of general applicability and virtually permits the preparation of a large variety of multi-element NPs in one step.展开更多
文摘This paper reviews the recent achievements in the immobilization of metal nanoparticles on ion-exchange resins and the related catalytic application. The focus is on the production processes for fine and commodity chemicals for which a low environmental impact has been demonstrated. The most significant papers that appeared in the literature from January 2010 to July 2014 have been covered. Their uses in unselective processes, bulk chemicals production, fuel cells components, as well as the use of metal-free ion-exchange resins in acid / base-catalysed reactions, were not included.
文摘Palladium based catalysts are the most active for methane oxidation. The tuning of their composition, structure and morphology at macro and nanoscale can alter significantly their catalytic behavior and robustness with a strong impact on their overall performances. Among the several combinations of supports and promoters that have been utilized, Pd/CeO2 has attracted a great attention due to its activity and durability coupled with the unusually high degree of interaction between Pd/Pd O and the support. This allows the creation of specific structural arrangements which profoundly impact on methane activation characteristics. Here we want to review the latest findings in this area, and particularly to envisage how the control(when possible) of Pd-CeO2 interaction at nanoscale can help in designing more robust methane oxidation catalysts.
基金supported by the MATTM (Italy) for the PIRODE Project No 94the MSE for the PRIT Project Industria 2015the MIUR (Italy) for the FIRB 2010 Project RBFR10J4H7 002 and HYDROLAB2
文摘Few layer graphene （FLG）, multi-walled carbon nanotubes （CNTs） and a nanotube-graphene composite （CNT-FLG） were used as supports for palladium nanoparticles. The catalysts, which were characterized by transmission electron microscopy, Raman spectroscopy and X-ray diffraction, were used as anodes in the electrooxidation of ethanol, ethylene glycol and glycerol in half cells and in passive direct ethanol fuel cells. Upon Pd deposition, a stronger interaction was found to occur between the metal and the nanotube-graphene composite and the particle size was significantly smaller in this material （6.3 nm）, comparing with nanotubes and graphene alone （8 and 8.4 nm, respectively）. Cyclic voltammetry experiments conducted with Pd/CNT, Pd/FLG and Pd/CNT-FLG in 10 wt% ethanol and 2 M KOH solution, showed high specific currents of 1.48, 2.29 and 2.51 mA-/zgp-d, respectively. Moreover, the results obtained for ethylene glycol and glycerol oxidation highlighted the excellent electrocatalytic activity of Pd/CNT-FLG in terms of peak current density （up to 3.70 mAgd for ethylene glycol and 1.84 mAfor glycerol, respectively）. Accordingly, Pd/CNT-FLG can be considered as the best performing one among the electrocatalysts ever reported for ethylene glycol oxidation, especially considering the low metal loading used in this work. Direct ethanol fuel cells at room temperature were studied by obtaining power density curves and undertaking galvanostatic experiments. The power density outputs using Pd/CNT, Pd/FLG and Pd/CNT-FLG were 12.1, 16.3 and 18.4 mW.cm-2, respectively. A remarkable activity for ethanol electrooxidation was shown by Pd/CNT-FLG anode catalyst. In a constant current experiment, the direct ethanol fuel cell containing Pd/CNT-FLG could continuously deliver 20 mA.cm-2 for 9.5 h during the conversion of ethanol into acetate of 30%, and the energy released from the cell was about 574 J.
基金the Italian Ministry of University and Research(MUR)through the“Rita Levi Montalcini 2018”Fellowship(Grant number PGR18MAZLI)ENEA–UNIMIB PNRR agreement(Attività1.1.3 del PNRR POR H2)+1 种基金the Ministry of Science and Technology(State of Israel)and the Ministry of Foreign Affairs and International Cooperation–Directorate General for Cultural and Economic Promotion and Innovation(Italian Republic),respectively,within the bilateral project Italy-Israel(WE-CAT)the Italian ministry MUR for funding through the FISR 2019 project AMPERE(FISR2019_01294)。
文摘Hydrogen production via water electrolysis defines the novel energy vector for achieving a sustainable society.However,the true progress of the given technology is hindered by the sluggish and complex hydrogen evolution reaction(HER)occurring at the cathodic side of the system where overpriced and scarce Pt-based electrocatalysts are usually employed.Therefore,efficient platinum group metals(PGMs)-free electrocatalysts to carry out HER with accelerated kinetics are urgently demanded.In this scenario,molybdenum disulfide(MoS_(2))owing to efficacious structural attributes and optimum hydrogen-binding free energy(ΔG_(H*))is emerging as a reliable alternative to PGMs.However,the performance of MoS_(2)-based electrocatalysts is still far away from the benchmark performance.The HER activity of MoS_(2)can be improved by engineering the structural parameters i.e.,doping,defects inducement,modulating the electronic structure,stabilizing the 1 T phase,creating nanocomposites,and altering the morphologies using appropriate fabrication pathways.Here,we have comprehensively reviewed the majority of the scientific endeavors published in recent years to uplift the HER activity of MoS_(2)-based electrocatalysts using different methods.Advancements in the major fabrication strategies including hydrothermal synthesis methods,chemical vapor deposition,exfoliation techniques,plasma treatments,chemical methodologies,etc.to tune the structural parameters and hence their ultimate influence on the electrocatalytic activity in acidic and/or alkaline media have been thoroughly discussed.This study can provide encyclopedic insights about the fabrication routes that have been pursued to improve the HER performance of MoS_(2)-based electrocatalysts.
文摘1 Results The development of the concepts of nanotechnology has given an important impact on the design of new polymer based materials which are in most cases characterized by a multiphase morphology. When at least one phase has nanometric dimension(s) the system can be considered as a nanocomposite where the interface is not only determining for the adhesion but also may play a role in some bulk properties. Indeed in nanostructured multiphase solids the interface is significant as a bulk component. The...
基金R.V.and S.G.acknowledge Universita delFInsubria for partial funding.J.A.R.N.is very grateful to Spanish MINECO(No.CTQ2017-84692-R)and EU Feder funding.C.D.N.and C.P.acknowledge University of Cam erinofor partial funding.
文摘Hydrocarbons separation in petrochemical industries is a key,energy-consuming stage in the manufacture of high-quality added-value products—hence the need for more efficient materials and environmentally friendly methodologies to improve this process.In this context,we have studied the effect of metal-organic frameworks(MOFs)pore functionalization in hexane isomers separation,isolating the robust isoreticular zinc(ll)bipyrazolates Zn(BPZ),showing no pore decoration,Zn(Me_(2)BPZ),the pores of which are decorated with apolar methyl groups,and Zn(BPZ(NH_(2))_(2)),the spacers of which possess polar Lewis-basic functions(H_(2)BPZ=1H,1'H-4,4'-bipyrazole;H_(2)Me_(2)BPZ=3,3'-dimethyl-1H,1'H-4,4'-bipyrazole;H_(2)BPZ(NH_(2))_(2)=3,5-diamino-1H,1'H-4,4'-bipyrazole;DMF=dimethylformamide).After characterizing Zn(BPZ(NH_(2))_(2))as per its crystal structure and thermal behaviour,and all the three MOFs as per their textural properties,we investigated,from the experimental and computational points of view,the impact of the square one-dimensional channels decoration on the separation of the hexane isomers,demonstrating the relevance of pore constrictions in the resolution of the title alkanes mixture.
基金The financial support of European Union's Horizon2020 Research and Innovation program under Grant agreements No.737093 and No.720853
文摘The rational design of complex nanostructures is of paramount importance to gain control over their chemical and physical properties.Recently,magnetic-plasmonic heterostructured nanocrystals have been recognized as key players in nanomedicine as multifunctional therapeutic-diagnostic tools and in catalysis.Here we show how the properties of gold-iron oxide heterostructured nanocrystals can be tuned by chemical doping of the magnetic subunit.The divalent cations in the iron oxide were substituted with cobalt and manganese to obtain a general formula Au-MFe2O4(M=Fe,Co,Mn).Magnetic properties of the heterostructures could be tuned,while maintaining well-defined plasmon resonance signatures,confirming the dual magnetic-plasmonic functional capability of these nanostructures.
文摘A frontier topic in nanotechnology is the realization of multifunctional nanoparticles （NPs） via the appropriate combination of different elements of the periodic table. The coexistence of Fe and Ag in the same nanostructure, for instance, is interesting for nanophotonics, nanomedicine, and catalysis. However, alloying of Fe and Ag is inhibited for thermodynamic reasons. Here, we describe the synthesis of Fe-doped Ag NPs via laser ablation in liquid solution, bypassing thermodynamics constraints. These NPs have an innovative structure consisting of a scaffold of face-centered cubic metal Ag alternating with disordered Ag-Fe alloy domains, all arranged in a truffle-like morphology. The Fe-Ag NPs exhibit the plasmonic properties of Ag and the magnetic response of Fe-containing phases, and the surface of the Fe-Ag NPs can be functionalized in one step with thiolated molecules. Taking advantage of the multiple properties of Fe-Ag NPs, the magnetophoretic amplification of plasmonic properties is demonstrated with proof-of-concept surface-enhanced Raman scattering and photothermal heating experiments. The synthetic approach is of general applicability and virtually permits the preparation of a large variety of multi-element NPs in one step.
