A carbon supported Pd（Pd/C） catalyst used as the anodic catalyst in the direct formic acid fuel cells（DFAFC） was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate（EDTA） a...A carbon supported Pd（Pd/C） catalyst used as the anodic catalyst in the direct formic acid fuel cells（DFAFC） was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate（EDTA） as stabilizer and complexing agent. This method is very simple. The average size of the Pd particles in the Pd/C catalyst prepared with the improved complex reduction method is as small as about 2.1 nm and the Pd particles in the Pd/C catalyst possess an excellent uniformity. The Pd/C catalyst shows a high electrocatalytic activity and stability for the formic acid oxidation.展开更多
Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials. For in-stance, the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide. In...Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials. For in-stance, the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide. In this study, the chemisorption of sulfur on the surface of deactivated Pd/C was detected by energy dispersive spec-trometer and X-ray photoelectron spectroscopy. Sulfur compounds poison the Pd/C catalyst and increase the forma-tion of azo deposit, reducing the activity of catalyst. We report a mild method to regenerate the Pd/C catalyst: wash the deposit by N,N-dimethylformamide and oxidize the chemisorbed sulfur by hot air. The regenerated Pd/C cata-lyst can be reused at least ten runs with stable activity.展开更多
The copolymerization of CO and styrene catalyzed by Pd/C toward the formation of polyketones （PK）was studied in the N-valeronitrile-N＆#39;-methylimidazolium hexafluorophosphate （[C4CNmim]＋PF6-） medium. The synth...The copolymerization of CO and styrene catalyzed by Pd/C toward the formation of polyketones （PK）was studied in the N-valeronitrile-N＆#39;-methylimidazolium hexafluorophosphate （[C4CNmim]＋PF6-） medium. The synthe-sized PK was characterized by Fourier transform infrared（FTIR）, elemental analysis, 13C-nuclear magnetic resonance （13C-NMR）, differential scanning calorimetry （DSC）, thermogravimetric analysis （TGA） and gel permeation chro-matography （GPC）. The supported ionic liquid film on the surface of Pd/C catalyst can prevent the products from covering the hole of active carbon due to its chemical stability and weak coordination ability with metal ions, and thus efficiently improve the catalytic activity. The effects of different amounts of ionic liquid on the catalytic activity and reusability of the catalyst and the molecular weight of PK were discussed. When the usage of ionic liquid is 10wt%（0.1 g ionic liquid/1 g active carbon carrier） and the theoretical content of Pd2＋is 5wt%（0.05 g Pd2＋/1 g active car-bon carrier）, the highest catalytic activity 2 963.64 gSTCO/（gPd＆#183;h） is achieved with the molecular weight and polydispersity index of PK as Mn=9 684, Mw=13 452 and Mw/Mn=1.389.展开更多
基金Supported by the "863" Program of Science and Technology Ministry of China(Nos.2006AA05Z137, 2007AA05Z143 and 2007AA05Z159)National Natural Science Foundation of China(Nos.20433060, 20473038, 20573057 and 20703043)the Natural Science Foundation of Jiangsu Province, China(No.BK2006224).
文摘A carbon supported Pd（Pd/C） catalyst used as the anodic catalyst in the direct formic acid fuel cells（DFAFC） was prepared via the improved complex reduction method with sodium ethylenediamine tetracetate（EDTA） as stabilizer and complexing agent. This method is very simple. The average size of the Pd particles in the Pd/C catalyst prepared with the improved complex reduction method is as small as about 2.1 nm and the Pd particles in the Pd/C catalyst possess an excellent uniformity. The Pd/C catalyst shows a high electrocatalytic activity and stability for the formic acid oxidation.
基金Supported by the Natural Science Foundation of Zhejiang Provincial （LYI2B03009） and Program for Zhejiang Leading Team of Science and Technology Innovation （2011 R09020-03）.
文摘Deactivation of Pd/C catalyst often occurs in liquid hydrogenation using industrial materials. For in-stance, the Pd/C catalyst is deactivated severely in the hydrogenation of N-(3-nitro-4-methoxyphenyl) acetamide. In this study, the chemisorption of sulfur on the surface of deactivated Pd/C was detected by energy dispersive spec-trometer and X-ray photoelectron spectroscopy. Sulfur compounds poison the Pd/C catalyst and increase the forma-tion of azo deposit, reducing the activity of catalyst. We report a mild method to regenerate the Pd/C catalyst: wash the deposit by N,N-dimethylformamide and oxidize the chemisorbed sulfur by hot air. The regenerated Pd/C cata-lyst can be reused at least ten runs with stable activity.
基金Supported by the Tianjin Natural Science Foundation(No.07JCYBJC00600)
文摘The copolymerization of CO and styrene catalyzed by Pd/C toward the formation of polyketones （PK）was studied in the N-valeronitrile-N＆#39;-methylimidazolium hexafluorophosphate （[C4CNmim]＋PF6-） medium. The synthe-sized PK was characterized by Fourier transform infrared（FTIR）, elemental analysis, 13C-nuclear magnetic resonance （13C-NMR）, differential scanning calorimetry （DSC）, thermogravimetric analysis （TGA） and gel permeation chro-matography （GPC）. The supported ionic liquid film on the surface of Pd/C catalyst can prevent the products from covering the hole of active carbon due to its chemical stability and weak coordination ability with metal ions, and thus efficiently improve the catalytic activity. The effects of different amounts of ionic liquid on the catalytic activity and reusability of the catalyst and the molecular weight of PK were discussed. When the usage of ionic liquid is 10wt%（0.1 g ionic liquid/1 g active carbon carrier） and the theoretical content of Pd2＋is 5wt%（0.05 g Pd2＋/1 g active car-bon carrier）, the highest catalytic activity 2 963.64 gSTCO/（gPd＆#183;h） is achieved with the molecular weight and polydispersity index of PK as Mn=9 684, Mw=13 452 and Mw/Mn=1.389.
