Pt-TiO2 nanotubes with tube diameter of -120 nm and uniformly dispersed Pt particles（size of -2 nm） were successfully synthesized via a carbon nanotube（CNT） templating method followed by a photo-deposition process...Pt-TiO2 nanotubes with tube diameter of -120 nm and uniformly dispersed Pt particles（size of -2 nm） were successfully synthesized via a carbon nanotube（CNT） templating method followed by a photo-deposition processing of Pt nanoparticles. The as-obtained Pt-TiO2 NTs possess both enhanced visible light absorption and reduced recombination of photogenerated electrons and holes. These merits boost the Pt-TiO2 NTs an excellent photocatalytic material toward photooxidation of a variety of low molecular hydrocarbons under atmospheric environment.展开更多
Xe-129-NMR and TEM were used to study the location and dispersion of Pt particles in KL zeolite with lanthanum incorporation. Owing to the interaction between Pt and La, more Pt particles accompanying La3+ were locate...Xe-129-NMR and TEM were used to study the location and dispersion of Pt particles in KL zeolite with lanthanum incorporation. Owing to the interaction between Pt and La, more Pt particles accompanying La3+ were located in the inner channels of KL zeolite, rather than agglomerated in the external surface. The dispersion of Pt particles was therefore improved. Pt/KL zeolite modified by La showed a little lower reactivity for aromatization of n-hexane, but much higher resistance to sulfur-poisoning because of the existence of new acidic sites.展开更多
Constructing synergistic active sites and optimizing the cooperative adsorption energies for hydrogen and hydroxyl based intermediates are two essential strategies to improve the sluggish kinetics of hydrogen evolutio...Constructing synergistic active sites and optimizing the cooperative adsorption energies for hydrogen and hydroxyl based intermediates are two essential strategies to improve the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline medium.However,it is still in its infancy to simultaneously achieve these goals,especially for designing a well-defined carrier with multiple hydroxyl adsorption sites.Herein,the Ni(HCO_(3))_(2)nanoplates(NHC)with horizontal interfaces sites of Ni-terminated NiO,NiOOH,NiCOO,and Ni(OH)_(2)were employed as the hydroxyl adsorption active sites,which could anchor Pt particles with hydrogen adsorption active sites,constructing the synergistic active sites(NHC-Pt)for HER catalysis.Evidenced by X-ray photoelectron spectroscopy(XPS)and extended X-ray absorption fine structure(EXAFS),the NHC could affect the chemical state and electronic structure of Pt particles by forming bond of Pt-O which could reduce the reaction energy barriers,facilitate the adsorption of hydrogen and establishment of H–H bond.Furthermore,density functional theory(DFT)theoretical calculation revealed that the related process of hydroxide was the rate-determining step.It is demonstrated the hydroxyl group presents the lowest energy barrier for desorption in the process of HER when the gradual desorption process could be described as a migration from Ni(HCO_(3))_(2)·OH directly or via other Ni-based systems formed after partial decomposition of nickel hydrocarbonate to Ni(OH)_(2)…OH with following desorption.As a result,the NHC-Pt hierarchical nanostructure demonstrated superior activity towards HER in a pH-universal solution.This enhancement can be attributed to the optimized electronic structure of Pt,the migration of hydroxyl group on NHC substrates,and the synergistic effects between the NHC carrier and Pt particles.展开更多
One fundamental challenge in exploiting direct methanol fuel cells(DMFCs)is the preparation of inex-pensive,high active electrocatalysts,which are highly active and durable for the two half-reactions,i.e.,the methanol...One fundamental challenge in exploiting direct methanol fuel cells(DMFCs)is the preparation of inex-pensive,high active electrocatalysts,which are highly active and durable for the two half-reactions,i.e.,the methanol oxidation reaction(MOR)at the anode and the oxygen reduction reaction(ORR)at the cathode.Platinum group metals-based catalysts have been known the governing dual-functional electro-catalysts based on the literature reports.But these catalysts are expensive and commercialize the DMFC less attractive.In addition to the high-cost,there are also methanol crossover,CO poisoning,long-term instability,and other problems as for Pt-based spurs.For the dual-role MOR&ORR catalysts,methanol crossover is inevitable to a certain extent on the current development of DMFC with losses in terms of cell voltage.In this regard,one strategy is to exploit high selective anodic/cathodic electrocatalysts to cap-italize the energy density at a high concentration of methanol.According to the summary results,there are mainly two types of dual-role electrocatalysts:one is Pt-support/co-catalyst(designated as P-S/C)for MOR/ORR,the other is catalyst/co-catalyst(designated as C/C)for MOR/ORR.This paper aims to review the design and construction of the various dual-role catalysts and give some discussion briefly.展开更多
基金financially supported by the National Key Project on Basic Research(No.2013CB933203)the Natural Science Foundation of China(Nos.21373224 and 21577143)+1 种基金the Natural Science Foundation of Fujian Province(Nos.2014H0054 and 2015J0544)the One Hundred Talents Program of the Chinese Academy of Sciences
文摘Pt-TiO2 nanotubes with tube diameter of -120 nm and uniformly dispersed Pt particles（size of -2 nm） were successfully synthesized via a carbon nanotube（CNT） templating method followed by a photo-deposition processing of Pt nanoparticles. The as-obtained Pt-TiO2 NTs possess both enhanced visible light absorption and reduced recombination of photogenerated electrons and holes. These merits boost the Pt-TiO2 NTs an excellent photocatalytic material toward photooxidation of a variety of low molecular hydrocarbons under atmospheric environment.
文摘Xe-129-NMR and TEM were used to study the location and dispersion of Pt particles in KL zeolite with lanthanum incorporation. Owing to the interaction between Pt and La, more Pt particles accompanying La3+ were located in the inner channels of KL zeolite, rather than agglomerated in the external surface. The dispersion of Pt particles was therefore improved. Pt/KL zeolite modified by La showed a little lower reactivity for aromatization of n-hexane, but much higher resistance to sulfur-poisoning because of the existence of new acidic sites.
基金supported from Science Fund for Distinguished Young Scholars of Nanjing Forestry University(No.JC2019002)。
文摘Constructing synergistic active sites and optimizing the cooperative adsorption energies for hydrogen and hydroxyl based intermediates are two essential strategies to improve the sluggish kinetics of hydrogen evolution reaction(HER)in alkaline medium.However,it is still in its infancy to simultaneously achieve these goals,especially for designing a well-defined carrier with multiple hydroxyl adsorption sites.Herein,the Ni(HCO_(3))_(2)nanoplates(NHC)with horizontal interfaces sites of Ni-terminated NiO,NiOOH,NiCOO,and Ni(OH)_(2)were employed as the hydroxyl adsorption active sites,which could anchor Pt particles with hydrogen adsorption active sites,constructing the synergistic active sites(NHC-Pt)for HER catalysis.Evidenced by X-ray photoelectron spectroscopy(XPS)and extended X-ray absorption fine structure(EXAFS),the NHC could affect the chemical state and electronic structure of Pt particles by forming bond of Pt-O which could reduce the reaction energy barriers,facilitate the adsorption of hydrogen and establishment of H–H bond.Furthermore,density functional theory(DFT)theoretical calculation revealed that the related process of hydroxide was the rate-determining step.It is demonstrated the hydroxyl group presents the lowest energy barrier for desorption in the process of HER when the gradual desorption process could be described as a migration from Ni(HCO_(3))_(2)·OH directly or via other Ni-based systems formed after partial decomposition of nickel hydrocarbonate to Ni(OH)_(2)…OH with following desorption.As a result,the NHC-Pt hierarchical nanostructure demonstrated superior activity towards HER in a pH-universal solution.This enhancement can be attributed to the optimized electronic structure of Pt,the migration of hydroxyl group on NHC substrates,and the synergistic effects between the NHC carrier and Pt particles.
基金supported by the National Natural Science Foun-dation of China(Nos.52076152 and 21773171)the Natural Science Foundation of Shanghai(No.20ZR1461000)the Fundamental Research Funds for the Central Universities offer help to support the project.
文摘One fundamental challenge in exploiting direct methanol fuel cells(DMFCs)is the preparation of inex-pensive,high active electrocatalysts,which are highly active and durable for the two half-reactions,i.e.,the methanol oxidation reaction(MOR)at the anode and the oxygen reduction reaction(ORR)at the cathode.Platinum group metals-based catalysts have been known the governing dual-functional electro-catalysts based on the literature reports.But these catalysts are expensive and commercialize the DMFC less attractive.In addition to the high-cost,there are also methanol crossover,CO poisoning,long-term instability,and other problems as for Pt-based spurs.For the dual-role MOR&ORR catalysts,methanol crossover is inevitable to a certain extent on the current development of DMFC with losses in terms of cell voltage.In this regard,one strategy is to exploit high selective anodic/cathodic electrocatalysts to cap-italize the energy density at a high concentration of methanol.According to the summary results,there are mainly two types of dual-role electrocatalysts:one is Pt-support/co-catalyst(designated as P-S/C)for MOR/ORR,the other is catalyst/co-catalyst(designated as C/C)for MOR/ORR.This paper aims to review the design and construction of the various dual-role catalysts and give some discussion briefly.
