Ni-ZrO2/CNTs对CO2甲烷化的催化性能
Catalytic Performance of Ni-ZrO2/CNTs in CO2 Methanation
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摘要: 采用浸渍法制备负载型催化剂Ni-ZrO2/CNTs, 考察金属Ni和ZrO2负载量对CO2甲烷化催化性能.利用X射线衍射, N2吸附, 扫描电子显微镜和H2-TPR (氢气程序升温还原) 等手段表征Ni-ZrO2/CNTs样品.与金属镍负载量7%催化剂Ni (7) /CNTs相比, ZrO2掺杂的催化剂Ni-ZrO2/CNTs对CO2甲烷化具有更高的催化活性, 且随着ZrO2掺杂量的增加先增大后减小, ZrO2负载掺杂量为15%的催化剂Ni (7) -ZrO2 (15) /CNTs的催化性能最好.这归因于ZrO2能够提高催化剂载体的Lewis碱度和抑制金属镍粒子在高温还原过程中烧结, 从而改善CO2在催化剂表面的吸附能力和提供更多的反应活性位.Abstract: The supported catalysts Ni-ZrO2/CNT was prepared by means of impregnation so as to find out about the catalytic performance of Ni and ZrO2 in CO2 methanation.Several techniques such as X-ray diffraction, N2-sorption, scanning electron microscope, and H2-temperature-programmed reduction were employed to characterize the thus-obtained samples.Compared with Ni (7) /CNTs with 7% metallic nickel loading, ZrO2-doped Ni-ZrO2/CNTs catalysts exhibited higher catalytic activity, which increased and then decreased with the increase of ZrO2 doping.Ni (7) -ZrO2 (15) /CNTs with 15% of ZrO2 doping was found to have the best catalytic activity.It’s ascribed to the enhanced Lewis basicity of catalyst support and the restrained sintering of metallic nickel in high-temperature reduction system, which has led to the improved sorption capacity of CO2 on the Ni (7) -ZrO2 (15) /CNTs surface and sufficient reactive sites for CO2 methanation