合成方法对Co基介孔二氧化硅纳米球丙烷脱氢性能的影响

Effect of synthetic method on Co-containing mesoporous silica nanospheres for propane dehydrogenation

以树枝状介孔二氧化硅纳米球为载体、Co为活性组分,分别采用等体积浸渍法、嫁接法和掺杂法制备了含Co介孔二氧化硅纳米球催化剂,利用XRD、SEM、N_(2)吸附-脱附、XPS等方法对催化剂进行表征,考察了催化剂的丙烷脱氢制丙烯的催化活性。实验结果表明,在嫁接法和掺杂法制备的催化剂中,活性组分Co的分散性更好,主要以Co^(2+)形式存在并与载体产生较强的相互作用;掺杂法合成过程简单,催化剂中树枝状介孔二氧化硅纳米球载体的结构保持更完整,催化剂表现出良好的丙烷脱氢活性和稳定性。

The dendritic mesoporous silica nanospheres(DMSNs)was used as the support and Co was chosen as the active component,the Co-containing DMSNs(Co-DMSNs)catalysts were prepared by the incipient wetness impregnation,grafting and doping method,respectively.The catalysts were characterized by XRD,SEM,N_(2) adsorption-desorption and XPS,and their catalytic activities for propane dehydrogenation to propylene were investigated.The experimental results indicate that the Co-DMSNs catalysts prepared by grafting or doping methods show higher dispersity of the active component Co which mainly exists in the form of Co^(2+)and interacts strongly with the support.Particularly,the synthetic process of doping method is relatively simple and the structure of DMSNs in the catalyst is maintained more regularly.The catalyst prepared by doping method exhibits good catalytic activity and stability for propane dehydrogenation.