介孔Ni/CaO-ZrO2纳米复合物催化甲烷和二氧化碳重整

采用溶胶-凝胶法制备了一种具有高热稳定性的介孔Ni/CaO-ZrO2纳米复合物.此纳米复合物在甲烷/二氧化碳重整中表现出较高的活性和稳定性,且经连续运行50h后,其催化活性没有明显降低,稳定性显著高于Ni/Al2O3或Ni/SiO2负载型催化剂.这是由于反应过程中纳米Ni颗粒尺寸被有效稳定以及碱性组分CaO的存在,催化剂中相互嵌合的Ni,ZrO2和CaO的颗粒尺寸均为10nm左右,堆积形成了海绵状的介孔结构.CaO的存在使催化剂具有较强的碱性,促进了反应物CO2的化学吸附和解离.

CO2 Reforming of CH4 over Mesoporous Ni/CaO-ZrO2 Nanocomposite

A novel mesoporous Ni/CaO-ZrO2 nanocomposite was prepared by a the sol-gel method. The nanocomposite was used for CO2 reforming of CH4, and it exhibited high catalytic activity, thermal stability, and resistance to coking. After running in the fixed-bed reactor for 50 h, its catalytic activity hardly decreased, and only a small amount of carbon formed on the catalyst, meaning that the catalyst stability was better than Ni/Al2O3 or Ni/SiO2 catalyst. The nickel particles almost kept their original nanometer size during the reaction owing to that the size growth was inhibited by other components in the nanocomposite. In addition, CaO was favorable for the chemisorption of CO2 in the reaction and consequently improved the resistance to carbon deposition on the mesoporous Ni/CaO-ZrO2 nanocomposite.