(中南大學(xué) 材料科學(xué)與工程學(xué)院，長沙 410083)
摘 要: 以正硅酸乙酯和硝酸鎳為原料、乙二醇為還原劑，采用溶膠−凝膠法和超臨界干燥工藝制備負載金屬Ni納米線的SiO2復(fù)合氣凝膠。通過BET、XRD、TEM、TPR和H2-TPD等技術(shù)，對其物相組成和活性比表面進行表征。結(jié)果表明：負載Ni主要以金屬Ni單質(zhì)納米線的形態(tài)均勻分布在SiO2氣凝膠三維網(wǎng)絡(luò)骨架結(jié)構(gòu)上，該納米線直徑為1~5 nm、長度為10~80 nm，載體骨架結(jié)構(gòu)上存在尚未還原完全的Ni；隨Ni負載量的增加，Ni與載體SiO2 之間的相互作用逐漸減弱，催化劑的Ni活性中心點增多；負載Ni納米線顯示出較強的熱穩(wěn)定性。
關(guān)鍵字: 復(fù)合氣凝膠；微觀結(jié)構(gòu)；金屬納米線；原位法；熱穩(wěn)定性
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The silica composite aerogels doped with Ni nanowire were prepared by sol-gel and supercritical drying technique using orthosilicate ethyl ester and nickel nitrate as raw materials and ethylene glycol as reductant. The phase component and activity of specific surface of Ni-based catalysts were characterized with BET, XRD, TEM, TPR and H2-TPD techniques. The results show that, Ni nanowire and unreduced pure nickel distribute homogenously in the tri-dimensional SiO2 aerogel skeleton, the size of nanowire is 1−5 nm in diameter and 10−80 nm in length. With the increase of Ni content, the interaction between nickel species and SiO2 becomes weaker, and the active specific surface area of the catalyst increases. Ni nanowire/SiO2 aerogel catalysts have good thermal stability.
Key words: composite aerogel; microstructure; Ni nanowires; in-situ method; thermal stability
