【摘要】 采用冷等离子体炬技术制备了以水滑石为前驱体的Ni/Mg/Al催化剂,考察了La和Ce助剂的添加对催化剂结构及其对CH₄和CO₂重整催化性能的影响。利用XRD、BET、XPS及TG对催化剂进行了表征和性能测试。结果表明:冷等离子体炬能快速分解Ni/Mg/Al水滑石前驱体,生成具有介孔特性的水镁石相Mg（Ni,Al）O固溶体,并生成Ni0晶粒。在温度700℃、空速30 000 m L/（h·gcat）、V（CH4）∶V（CO2）=4∶6时,CH₄和CO₂的转化率分别为76.6%和61.8%。助剂Ce的添加增加了晶格氧的含量,促进了催化剂表面碳物种的消除,CH₄和CO₂的转化率分别提高了4%和7%。La的加入,抑制了Ni0晶粒的团聚,增加了Ni0的分散度,与未添加La的催化剂相比,非活性碳的生成量减少70%,表现出良好的抗积炭性能。更多还原

【Abstract】 Ni/Mg/Al catalysts doped with rare earth metals were prepared by cold plasma decomposition and reduction of hydrotalcite-like compound,and the effects of introduction of La and Ce on physico-chemical properties of prepared catalysts and catalytic performance of dry reforming of methane were studied.The catalysts were characterized by means of XRD,BET,XPS and TG techniques.The results suggested that hydrotalcite-like precursors were fastly decomposed by cold plasma torch to form mesoporous Mg（Ni,Al） O solid solution,and which generated Ni⁰ grain.In addition,the conversion of methane and carbon dioxide were 76.6% and 61.8% at 700 ℃ with V（CH₄） ∶ V（CO₂） = 4 ∶ 6,GHSV of 30 000 m L/（h ·gcat）.The introduction of Ce into the catalyst improved the concentration of lattice oxygen and promoted the elimination of carbon species on the catalyst surface,which made the conversion of methane and carbon dioxide increase by 4% and 7%,respectively.However,the introduction of La into the catalyst inhibited the agglomeration of Ni⁰ and improved the dispersion of Ni⁰,which caused non- active carbon deposition decrease by 70%,indicating that the catalyst possessed a better anti-coke property.更多还原