基于Ni/Ce_(1-x)Ni_x O_(2-δ)催化剂的甲烷部分氧化

Partial oxidation of methane based on Ni/Ce_(1-x)Ni_xO_(2-δ) catalyst

通过柠檬酸-EDTA联合络合法合成了具有萤石相结构的Ce_(1-x)Ni_xO_(2-δ)复合氧化物,并将其应用于甲烷部分氧化反应。XRD分析表明,当x≤0.3时,Ce_(1-x)Ni_xO_(2-δ)能形成纯相萤石结构,并且随着镍含量的增加,Ce_(1-x)Ni_xO_(2-δ)晶胞参数有逐步减小的趋势。在Ce_(1-x)Ni_xO_(2-δ)催化的甲烷部分氧化反应中,850℃时,甲烷转化率可达97.4%,H_2选择性达到98.9%,显示出良好的甲烷部分氧化催化活性,Ce_(1-x)Ni_xO_(2-δ)载体也具有较高的甲烷部分氧化催化活性,但其催化性能低于Ni/Ce_(1-x)Ni_xO_(2-δ),说明在Ni/Ce_(1-x)Ni_xO_(2-δ)表面负载的镍物种仍然是主要活性部位。

Ce1-xNixO2-δ mixed oxides with fluorite structure were synthesized by citric acid-EDTA combined complexing method and used as the catalyst for partial oxidation of methane. XRD results showed that Ce1-xNixO2-δ with purely fluorite phase could be synthesized while x〈~0.3, and crystal cell of Ce1-xNixO2-δ declined with content of nickel. Methane conversion of 97.4% and selectivity to H2 of 98.9% was obtained over Ce1-xNixO2-δ at 850 ℃. Ni/Ce1-xNixO2-δ support also exhibited relatively high catalytic activity, but was inferior to that of Ni/Ce1-xNixO2-δ, indicating that nickel species over surface of the catalyst were the main active sites.