介孔Ni/ZrO2催化剂的制备及甲烷二氧化碳重整催化性能

Preparation of Mesoporous Ni/ZrO2 Catalysts and Catalytic Performance for CO2 Reforming of CH4

分别使用氨水、氢氧化钠和碳酸钠作为沉淀剂,采用共沉淀回流法制备了Ni/ZrO2催化剂,并利用氮气吸附脱附(BET)、X射线粉末衍射(XRD)、和透射电子显微镜(TEM)对催化剂的结构性质进行了表征,同时考察了不同沉淀剂制备的Ni/ZrO2催化剂的甲烷二氧化碳重整催化性能。研究结果表明,三种催化剂都形成了介孔结构,具有较大的比表面积。但是沉淀剂的种类对催化剂的结构和Ni的分散度有显著的影响。采用氢氧化钠作为沉淀剂制备的的催化剂(Ni/ZrO2-SH)具有较大的比表面积,且无定形的氧化锆形成了海绵状的介孔结构,促进了Ni的高度分散。在重整反应中Ni/ZrO2-SH具有较高的催化活性和稳定性,750℃下甲烷的转化率达到84%,并且在10h时的反应过程只有轻微的失活。

Ni/ZrO2 catalysts were prepared by coprecipitation reflux method,using ammonia,sodium hydroxide and sodium carbonate as precipitators.The structure and morphology of the catalysts were characterized by BET,XRD and TEM.The catalytic performance of Ni-ZrO2 catalysts on carbon dioxide reforming of methane was also investigated.The results show that all catalysts exhibited large specific surface area,due to the formation of mesoporous structure.However,the type of precipitant has a significant influence on the structure of samples and the dispersion of Ni.The Ni/ZrO2-SH sample prepared with sodium hydroxide as precipitant possessed higher specific surface area.It formed a spongy mesoporous structure because of the amorphous zirconia,which promotes the high dispersion of Ni.It exhibited the highest catalytic activity(methane conversion rate of 84%)and mild deactivation during the 10h test among other studied Ni/ZrO2 catalysts.