Pt-WO3 nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method.The morphology,composition,nanostructure,electrochemical characteristics and electrocatalytic activity ...Pt-WO3 nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method.The morphology,composition,nanostructure,electrochemical characteristics and electrocatalytic activity were characterized,and the formation mechanism was investigated.The average particle size was 2.3 nm,the same as that of Pt/C catalyst.The W/Pt atomic ratio was 1/20,much lower than the design of 1/3.The deposition of WO3·xH2O nanoparticles on Vulcan XC-72R carbon black was found to be very difficult by TEM.From XPS and XRD,the Pt nanoparticles were formed in the colloidal solution of Na2WO4,the EG insoluble Na2WO4 resulted in the decreased relative crystallinity and increased crystalline lattice constant compared with those of Pt/C catalyst and,subsequently,the higher specific electrocatalytic activity as determined by CV.The Pt-mass and Pt-electrochemically-active-specific-surface-area based anodic peak current densities for ethanol oxidation were 422.2 mA·mg-1Pt and 0.43 mA·cm-2Pt,1.2 and 1.1 times higher than those of Pt/C catalyst,respectively.展开更多
A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting ...A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting the ultraviolet-visible spectroscopy technology and H+ concentration detector. Moreover, the amount of Na OH that effectively coordinates Pt4+ has been tentatively qualified and the heating parameters during the preparation process of Pt/C have also been optimized. As investigated, the optimized 20-(1/22)-140-2 Pt/C(20 wt%Pt;m(Pt):m(Na OH)=1/22;heating temperature: 140 °C, heating time: 2 h) exhibits higher electrocatalytic activity towards oxygen reduction reaction(ORR) than the commercial 20 wt% Pt/C(E-TEK) in acidic media. This work provides a theoretical reserve and technical accumulation for industrialized mass production of highly efficient Pt/C catalysts for ORR in proton exchange membrane fuel cells.展开更多
基金Funded by the National Basic Research Program of China (No. 2009CB220100)the Beijing Excellent Talent Support Program (No. 20071D1600300396)
文摘Pt-WO3 nanoparticles uniformly dispersed on Vulcan XC-72R carbon black were prepared by an ethylene glycol method.The morphology,composition,nanostructure,electrochemical characteristics and electrocatalytic activity were characterized,and the formation mechanism was investigated.The average particle size was 2.3 nm,the same as that of Pt/C catalyst.The W/Pt atomic ratio was 1/20,much lower than the design of 1/3.The deposition of WO3·xH2O nanoparticles on Vulcan XC-72R carbon black was found to be very difficult by TEM.From XPS and XRD,the Pt nanoparticles were formed in the colloidal solution of Na2WO4,the EG insoluble Na2WO4 resulted in the decreased relative crystallinity and increased crystalline lattice constant compared with those of Pt/C catalyst and,subsequently,the higher specific electrocatalytic activity as determined by CV.The Pt-mass and Pt-electrochemically-active-specific-surface-area based anodic peak current densities for ethanol oxidation were 422.2 mA·mg-1Pt and 0.43 mA·cm-2Pt,1.2 and 1.1 times higher than those of Pt/C catalyst,respectively.
文摘A solvothermal assisted ethylene glycol reduction method is a common technology for Pt/C catalysts preparation. Here, the coordination mechanism of the Pt-containing species is deeply studied by innovatively adopting the ultraviolet-visible spectroscopy technology and H+ concentration detector. Moreover, the amount of Na OH that effectively coordinates Pt4+ has been tentatively qualified and the heating parameters during the preparation process of Pt/C have also been optimized. As investigated, the optimized 20-(1/22)-140-2 Pt/C(20 wt%Pt;m(Pt):m(Na OH)=1/22;heating temperature: 140 °C, heating time: 2 h) exhibits higher electrocatalytic activity towards oxygen reduction reaction(ORR) than the commercial 20 wt% Pt/C(E-TEK) in acidic media. This work provides a theoretical reserve and technical accumulation for industrialized mass production of highly efficient Pt/C catalysts for ORR in proton exchange membrane fuel cells.
