分别通过自组装法(AS)和浸渍法(WI)制备得到纳米催化剂Pt/γ-Al2O3-AS和Pt/γ-Al2O3-WI,并用于评价甲苯、异丙醇、丙酮、乙酸乙酯等易挥发性有机物(VOCs)的氧化性能.通过各种表征手段探究了催化剂形态、结构及表面性质与催化剂氧化活性...分别通过自组装法(AS)和浸渍法(WI)制备得到纳米催化剂Pt/γ-Al2O3-AS和Pt/γ-Al2O3-WI,并用于评价甲苯、异丙醇、丙酮、乙酸乙酯等易挥发性有机物(VOCs)的氧化性能.通过各种表征手段探究了催化剂形态、结构及表面性质与催化剂氧化活性的关系.结果表明,Pt/γ-Al2O3-AS在低温下即可实现VOCs的完全氧化.在气体浓度(体积分数)为1000×10-6,空速为18000 m L·g-1·h-1的条件下,甲苯、异丙醇、丙酮、乙酸乙酯被Pt/γ-Al2O3-AS催化剂完全氧化的温度分别为130、135、145、215°C,展现出了优异的氧化性能,且具有很好的稳定性.该催化剂较高的比表面积、较小的Pt纳米粒径、较好的Pt纳米颗粒分散度、更好的低温还原效果及丰富的表面羟基是具有较高催化活性的重要因素.展开更多
The promoting effect of La2O3 on Ni/γ-Al2O3 methanation catalyst was investigated by XPS, TPR and TPD methods. Results indicated that La2O3 can be partially reduced to LaOx (x＜3/2) during H2 reduction of the Ni cata...The promoting effect of La2O3 on Ni/γ-Al2O3 methanation catalyst was investigated by XPS, TPR and TPD methods. Results indicated that La2O3 can be partially reduced to LaOx (x＜3/2) during H2 reduction of the Ni catalysts with La2O3.The excess charge associated with the LaOx can be transfered to Ni. It weakened C-O bond strength, accelerated CO dissociation, proportionation and methanation reaction.The interaction between NiO and Al2O3 can be suppressed and the formation of NiAl2O4-like species can be reduced by adding La2O3. With the increase of La2O3 con tents the fraction of NiO which is easier to be reduced becomes larger.The fact that there was more residual H2 on the catalyst with La2O3 means that it is able to retain some H2. Besides, the distribution of CO adsorption sites of the Ni catalyst was shifted by adding La2O3.展开更多
基金supported by the Key Innovation Team of Science&Technology in Zhejiang Province,China(2011R50017)National HighTechnology Research and Development Program of China(863)(2013AA065005)~~
文摘分别通过自组装法(AS)和浸渍法(WI)制备得到纳米催化剂Pt/γ-Al2O3-AS和Pt/γ-Al2O3-WI,并用于评价甲苯、异丙醇、丙酮、乙酸乙酯等易挥发性有机物(VOCs)的氧化性能.通过各种表征手段探究了催化剂形态、结构及表面性质与催化剂氧化活性的关系.结果表明,Pt/γ-Al2O3-AS在低温下即可实现VOCs的完全氧化.在气体浓度(体积分数)为1000×10-6,空速为18000 m L·g-1·h-1的条件下,甲苯、异丙醇、丙酮、乙酸乙酯被Pt/γ-Al2O3-AS催化剂完全氧化的温度分别为130、135、145、215°C,展现出了优异的氧化性能,且具有很好的稳定性.该催化剂较高的比表面积、较小的Pt纳米粒径、较好的Pt纳米颗粒分散度、更好的低温还原效果及丰富的表面羟基是具有较高催化活性的重要因素.
文摘The promoting effect of La2O3 on Ni/γ-Al2O3 methanation catalyst was investigated by XPS, TPR and TPD methods. Results indicated that La2O3 can be partially reduced to LaOx (x＜3/2) during H2 reduction of the Ni catalysts with La2O3.The excess charge associated with the LaOx can be transfered to Ni. It weakened C-O bond strength, accelerated CO dissociation, proportionation and methanation reaction.The interaction between NiO and Al2O3 can be suppressed and the formation of NiAl2O4-like species can be reduced by adding La2O3. With the increase of La2O3 con tents the fraction of NiO which is easier to be reduced becomes larger.The fact that there was more residual H2 on the catalyst with La2O3 means that it is able to retain some H2. Besides, the distribution of CO adsorption sites of the Ni catalyst was shifted by adding La2O3.
