掺杂氧化物对Ni-ZrO2-Al2O3催化剂的性能影响

The Effect of the Oxide Doping on the Property of Ni-ZrO2-Al2O3 Catalyst

关键词:  掺杂氧化物  二氧化碳  甲烷  重整

Key words:  doped oxide  carbon dioxide  methane  reforming

摘要:

用水热合成法分别制备Ni-ZrO₂-Al₂O₃和Ni-M_xO_y-ZrO₂-Al₂O₃催化剂,并用XRD、H₂-TPR、H₂-TPD和CO₂-TPD方法对对催化剂的晶相结构、活性中心、表面酸碱性等进行表征,同时以CO₂重整CH₄反应为探针考察催化剂的活性及稳定性。结果表明,在Ni-ZrO₂-Al₂O₃催化剂中掺杂不同的金属氧化物M_xO_y能改变催化剂的晶相结构,对催化剂表面活性和碱性中心有一定程度的调控作用。掺杂BaO、CeO2和K₂O后的催化剂反应的初活性明显增加,在850℃时,使CH₄的转化率分别达到92.31%、90.29%和90.06%,CO₂的转化率分别达到94.37%、93.94%和93.22%。800℃条件下反应100h后,Ni-BaO-ZrO₂-Al₂O₃催化剂上的CH₄转化率基本上维持在85%。

Abstract:

Hydrothermal method was applied to prepare Ni-ZrO₂-Al₂O₃ and Ni-M_<em>xO_<em>y-ZrO₂-Al₂O₃.Crystalline structures, active centers and alkalinity of the catalysts were characterized by XRD, H₂-TPR, H₂-TPD and CO₂-TPD.The CO₂ reforming of CH₄ reaction was chosen to investigate the catalytic activity and stability of the catalysts.The results show that the phase of every ingredient in the catalysts which was prepared by hydrothermal method is singleness.The results of the activity of catalytic show that the activity of Ni-BaO-ZrO₂-Al₂O₃, Ni-CeO₂-ZrO₂-Al₂O₃ and Ni-K₂O-ZrO₂-Al₂O₃ in the beginning of the reaction was better than others at 850℃, CH₄ conversion rate was reached 92.31%, 90.29% and 90.06% respectively, and CO₂ conversion rate was reached 94.37%, 93.94% and 93.22%.The results of the stability of catalytic show that the Ni-BaO-ZrO₂-Al₂O₃ catalyst displays higher stability than others for CO₂ reforming of CH₄:CH₄ conversion rate was maintained 85% after reacted 100h at 800℃.