助剂CuO和La2O3对NiO/α-Al2O3甲烷催化部分氧化制合成气引发过程的影响

采用分步浸渍法制备了NiO/α-Al₂O₃、NiO-CuO/α-Al₂O₃和NiO-La₂O₃/α-Al₂O₃三种催化剂，运用程序升温表面反应（TPSR）技术考察了助剂CuO和La₂O₃对NiO/α-Al₂O₃甲烷催化部分氧化（CPOM）反应引发过程的影响。结果表明，无论是否经过预还原处理，NiO/α-Al₂O₃催化剂在CH₄/O₂混合气氛下进行程序升温表面反应（CH₄/O₂-TPSR）时，即使升高到910℃也不能引发CPOM反应。添加助剂CuO或La₂O₃后，NiO-CuO/α-Al₂O₃和NiO-La₂O₃/α-Al₂O₃催化剂在CH₄/O₂-TPSR过程中均可以引发CPOM反应。原因分别是CuO促进了CH₄对NiO的还原以及抑制了O₂对Ni0的再氧化，La₂O₃减小了Ni晶粒粒径和还原时扩散阻力促进NiO的还原。

Effects of CuO and La2O3 promoters on the ignition process of NiO/α-Al2O3 catalyst for catalytic partial oxidation of methane to syngas

NiO/α-Al₂O₃, NiO-CuO/α-Al₂O₃ and NiO-La₂O₃/α-Al₂O₃ catalysts were prepared by multistep impregnation method. The effects of CuO and La₂O₃ promoters on the ignition process of NiO/α-Al₂O₃ catalyst for catalytic partial oxidation of methane (CPOM) to synthesis gas were studied by temperature-programmed surface reaction (TPSR) technique as well. The results indicated that the CPOM reaction could not be ignited over the NiO/α-Al₂O₃ catalyst with or without pre-reduction during the CH₄/O₂-TPSR process till 910℃. The CPOM reaction could be ignited on the NiO-CuO/α-Al₂O₃ catalysts, which ascribed to the addition of CuO was beneficial to reduction of NiO with CH₄ and restraining the re-oxidation of Ni0 by O₂. The CPOM reaction could be ignited on the NiO-La₂O₃/α-Al₂O₃ catalysts too, which should be due to fact that the addition of La₂O₃ was beneficial to decrease the diffused resistance during the reduction process for reducing the size of nickel crystal.