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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CH_4和CO_2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,CH_4和CO_2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,CH_4和CO_2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。
Hydrotalcite was used as precursor to prepare Ni / Mg / Al catalyst by cold plasma torch technology. The effects of La and Ce promoters on the structure of catalyst and its catalytic performance for CH_4 and CO_2 reforming were investigated. The catalysts were characterized and characterized by XRD, BET, XPS and TG. The results show that the cold plasma torch can rapidly decompose the Ni / Mg / Al hydrotalcite precursor to form the magnesian matrix Mg (Ni, Al) O solid solution with mesoporous properties and generate Ni0 grains. The conversion rates of CH 4 and CO 2 were 76.6% and 61.8% at the temperature of 700 ℃, the space velocity of 30 000 m L / (h · gcat) and V (CH 4): V (CO 2) = 4: 6, respectively. The addition of Ce, as an auxiliary, increased the content of lattice oxygen and promoted the elimination of carbon species on the surface of the catalyst. The conversion of CH 4 and CO 2 increased by 4% and 7%, respectively. The addition of La restrains the agglomeration of Ni0 grains and increases the dispersion of Ni0. Compared with the catalyst without La addition, the formation of non-activated carbon decreases by 70% and shows good anti-carbon deposition performance.