Thermal Stability of Gold Catalyst Supported on Mesoporous Titania Nanofibers

Abstract

By deposition-precipitation with urea method, gold was loaded on mesoporous TiO 2 whisker, which was prepared from a potassium titanate whisker precursor through solid phase sintering process. The morphology and structure of these as-prepared catalysts were characterized by N 2 adsorption-desorption, X-ray diffraction, and transmission electron microscopy. The reduction of 4-nitrophenol to 4-aminophenol by NaBH 4 was evaluated as a probe reaction. After calcination at high temperature, the activity of the catalysts supported on mesoporous TiO 2 nanofiber was well maintained, and the particle size of gold nanoparticles was hardly changed. This might be attributed to the peculiar crystallographic structure and mesoporous nanoarchitecture of the mesoporous TiO 2 whisker. 以二钛酸钾晶须为前驱体, 通过固相烧结工艺制备了介孔 TiO 2 晶须, 然后使用沉积沉淀法将 Au 纳米颗粒担载于其上, 并采用低温 N 2 吸附-脱附 X 射线衍射及透射电镜等技术对催化剂的形貌和结构进行了表征, 以 NaBH 4 还原对硝基苯酚 (PNP) 为探针反应, 评价了催化剂的活性及稳定性. 结果表明, 500 丰C 热处理前后, 介孔 TiO 2 负载的 Au 纳米颗粒的平均粒径变化不大, 且催化 PNP 还原活性得到了很好的保持. 这主要与介孔 TiO 2 晶须独特的双晶构型及介孔结构有关. The unique crystallographic structure and mesoporous architecture of the TiO 2 whisker ensure the excellent sinter-resistant properties of gold nanoparticles. Consequently, the activity of the catalyst supported on the mb-TiO 2 is well maintained after high temperature calcination.