通过超声浸渍法在堇青石表面固载石墨烯涂层从而制备得到Pd/石墨烯/堇青石催化剂,并研究其催化甲苯燃烧的性能。研究表明,石墨烯涂层显著提高了Pd粒子的分散度以及载体表面的疏水性。与Pd/堇青石催化剂相比,Pd/石墨烯/堇青石催化剂的甲...通过超声浸渍法在堇青石表面固载石墨烯涂层从而制备得到Pd/石墨烯/堇青石催化剂,并研究其催化甲苯燃烧的性能。研究表明,石墨烯涂层显著提高了Pd粒子的分散度以及载体表面的疏水性。与Pd/堇青石催化剂相比,Pd/石墨烯/堇青石催化剂的甲苯的起燃温度从180℃降至120℃,而且在水蒸气存在的情况下表现出更好的稳定性。动力学研究表明,Pd/石墨烯/堇青石催化剂上甲苯催化燃烧符合一级反应动力学规律,活化能为60.93 k J/mol。展开更多
Three-dimensionally ordered macro-/mesoporous alumina（3DOM Al2O3）-supported cobalt oxide and platinum nanocatalysts（xPt/yCo3O4/3DOM Al2O3,Pt mass fraction（x%）= 0-1.4%,Co3O4 mass fraction（y%） = 0-9.2%） were pre...Three-dimensionally ordered macro-/mesoporous alumina（3DOM Al2O3）-supported cobalt oxide and platinum nanocatalysts（xPt/yCo3O4/3DOM Al2O3,Pt mass fraction（x%）= 0-1.4%,Co3O4 mass fraction（y%） = 0-9.2%） were prepared using poly（methyl methacrylate） templating,incipient wetness impregnation and polyvinyl alcohol-protected reduction.The resulting xPt/yCo3O4/3DOM Al2O3 samples displayed a high-quality 3DOM architecture with macropores（180-200 nm in diameter） and mesopores（4-6 nm in diameter） together with surface areas in the range of 94 to 102m^2/g.Using these techniques,Co3O4 nanoparticles（NPs,18.3 nm） were loaded on the 3DOM Al2O3 surface,after which Pt NPs（2.3-2.5 nm） were uniformly dispersed on theyCo3O4/3DOM Al2O3.The1.3Pt/8.9Co3O4/3DOM Al2O3 exhibited the best performance for toluene oxidation,with a T（90%） value（the temperature required to achieve 90%toluene conversion） of 160 ℃ at a space velocity of20000 mL g^（-1） h^（-1）.It is concluded that the excellent catalytic performance of the 1.3Pt/8.9Co3O4/3DOM Al2O3 is owing to well-dispersed Pt NPs,the high concentration of adsorbed oxygen species,good low-temperature reducibility,and strong interaction between the Pt and Co3O4 NPs,as well as the unique bimodal porous structure of the support.展开更多
The copper based catalysts, CuO/T-Al2O3, CuO/y-Al2O3-cordierite （Cord） and CuO/Cord, were prepared by impregnation method. The catalytic activity of the catalysts was tested in absence and presence of water vapor,an...The copper based catalysts, CuO/T-Al2O3, CuO/y-Al2O3-cordierite （Cord） and CuO/Cord, were prepared by impregnation method. The catalytic activity of the catalysts was tested in absence and presence of water vapor,and the catalysts were characterized. Temperature program desorption （TPD） experiments or toluene and water on the catalysts were carried out. The influence of water vapor on the activity of the catalysts was discussed. Results showed that addition of the water vapor has a significant negative effect on the catalytic activity of the catalysts.The higher the concentration of the Water vapor in feed steam was, the lower the catalytic activity of the copper based catalysts became, which could be mainly ascribed to the competition of water molecules with toluene molecules for adsorption on the catalyst surfaces. TPD experiments showed that the strength of the interaction between water molecules and three catalysts followed the order： CuO/γ-Al2O3〉CuO/γ-Al2O3-Cord〉CuO/Cord. As a consequence of that, the degree of degradation in the catalytic activity of these three catalysts by the water vapor followed the order： CuO/γ-Al2O3〉CuO/y-Al2O3-Cord〉CuO/Cord. However, the negative effect of the water vapor was reversible.展开更多
Featuring an assembly of identical pores, through-pore anodic alumina （AAO） makes an ideal monolith-like cat- alyst support for volatile organic compound （VOC） combustion. This work employs the oxidation of toluen...Featuring an assembly of identical pores, through-pore anodic alumina （AAO） makes an ideal monolith-like cat- alyst support for volatile organic compound （VOC） combustion. This work employs the oxidation of toluene as a model reaction to investigate the applicability of AAO supported Pt catalysts in VOC catalytic combustion. In order to modify the microstructure of AAO, some AAO samples were exposed to hot water treatment （HWT） firstly. Re- sults show that the optimum HWT time is 18 h. Pt/HWT18 gives a toluene conversion of95%; at 200 ℃, which is comparable to the initial activity of commercial γ-A1203 particle supported Pt catalyst. Considering its confine- ment effect for the supported metal and its monolith-like compact unit, AAO support offers potential applications in VOC catalytic combustion.展开更多
文摘通过超声浸渍法在堇青石表面固载石墨烯涂层从而制备得到Pd/石墨烯/堇青石催化剂,并研究其催化甲苯燃烧的性能。研究表明,石墨烯涂层显著提高了Pd粒子的分散度以及载体表面的疏水性。与Pd/堇青石催化剂相比,Pd/石墨烯/堇青石催化剂的甲苯的起燃温度从180℃降至120℃,而且在水蒸气存在的情况下表现出更好的稳定性。动力学研究表明,Pd/石墨烯/堇青石催化剂上甲苯催化燃烧符合一级反应动力学规律,活化能为60.93 k J/mol。
基金supported by the National High Technology Research and Development Program of China(863 Program,2015AA034603)the National Natural Science Foundation of China(21377008)Foundation on the Creative Research Team Construction Promotion Project of Beijing Municipal Institutions
文摘Three-dimensionally ordered macro-/mesoporous alumina（3DOM Al2O3）-supported cobalt oxide and platinum nanocatalysts（xPt/yCo3O4/3DOM Al2O3,Pt mass fraction（x%）= 0-1.4%,Co3O4 mass fraction（y%） = 0-9.2%） were prepared using poly（methyl methacrylate） templating,incipient wetness impregnation and polyvinyl alcohol-protected reduction.The resulting xPt/yCo3O4/3DOM Al2O3 samples displayed a high-quality 3DOM architecture with macropores（180-200 nm in diameter） and mesopores（4-6 nm in diameter） together with surface areas in the range of 94 to 102m^2/g.Using these techniques,Co3O4 nanoparticles（NPs,18.3 nm） were loaded on the 3DOM Al2O3 surface,after which Pt NPs（2.3-2.5 nm） were uniformly dispersed on theyCo3O4/3DOM Al2O3.The1.3Pt/8.9Co3O4/3DOM Al2O3 exhibited the best performance for toluene oxidation,with a T（90%） value（the temperature required to achieve 90%toluene conversion） of 160 ℃ at a space velocity of20000 mL g^（-1） h^（-1）.It is concluded that the excellent catalytic performance of the 1.3Pt/8.9Co3O4/3DOM Al2O3 is owing to well-dispersed Pt NPs,the high concentration of adsorbed oxygen species,good low-temperature reducibility,and strong interaction between the Pt and Co3O4 NPs,as well as the unique bimodal porous structure of the support.
基金Supported by the National-Natural Science Foundation of China （20936001）, the Natural Science Foundation of Guangdong Province, and the State Key Lab of Subtropical Building Science, South China University of Technology （x2yj C709028Z）.
文摘The copper based catalysts, CuO/T-Al2O3, CuO/y-Al2O3-cordierite （Cord） and CuO/Cord, were prepared by impregnation method. The catalytic activity of the catalysts was tested in absence and presence of water vapor,and the catalysts were characterized. Temperature program desorption （TPD） experiments or toluene and water on the catalysts were carried out. The influence of water vapor on the activity of the catalysts was discussed. Results showed that addition of the water vapor has a significant negative effect on the catalytic activity of the catalysts.The higher the concentration of the Water vapor in feed steam was, the lower the catalytic activity of the copper based catalysts became, which could be mainly ascribed to the competition of water molecules with toluene molecules for adsorption on the catalyst surfaces. TPD experiments showed that the strength of the interaction between water molecules and three catalysts followed the order： CuO/γ-Al2O3〉CuO/γ-Al2O3-Cord〉CuO/Cord. As a consequence of that, the degree of degradation in the catalytic activity of these three catalysts by the water vapor followed the order： CuO/γ-Al2O3〉CuO/y-Al2O3-Cord〉CuO/Cord. However, the negative effect of the water vapor was reversible.
基金Supported by the National Natural Science Foundation of China(21106189,21036009)the Natural Science Foundation(S2011040001767)the Foundation from the Educational Commission(LYM11004)of Guangdong Province
文摘Featuring an assembly of identical pores, through-pore anodic alumina （AAO） makes an ideal monolith-like cat- alyst support for volatile organic compound （VOC） combustion. This work employs the oxidation of toluene as a model reaction to investigate the applicability of AAO supported Pt catalysts in VOC catalytic combustion. In order to modify the microstructure of AAO, some AAO samples were exposed to hot water treatment （HWT） firstly. Re- sults show that the optimum HWT time is 18 h. Pt/HWT18 gives a toluene conversion of95%; at 200 ℃, which is comparable to the initial activity of commercial γ-A1203 particle supported Pt catalyst. Considering its confine- ment effect for the supported metal and its monolith-like compact unit, AAO support offers potential applications in VOC catalytic combustion.
