物理化学学报2009，Vol.25Issue(11)：2261-2269,9.
具有良好热稳定性的Al_2O_3改性Fe_2O_3基金催化剂
Al_2O_3-Modified Fe_2O_3 Based Gold Catalysts with Good Thermal Stability
摘要
Abstract
Al_2O_3-modified Fe_2O_3 based gold catalysts with good thermal stability were prepared by co-precipitation and deposition-precipitation method. Characterization techniques, such as transmission electron microscope (TEM), X-ray diffraction (XRD), N_2 adsorption-desorption, and thermogravimetry-differential scanning calorimetry (TG-DSC), were used to investigate the structures, and surface morphologies of the catalysts. TEM results showed that after calcination at 500℃ the size distribution of the gold particles in the catalyst without Al_2O_3 doping was wide, the average diameter of the gold particles was about 7.0 nm and the size of the support particles ranged from 50 to 100 nm. However, the size distribution of the gold particles in the Al_2O_3-doped catalysts was narrow and the average diameter of the gold particles was around 5.0 nm. The Al_2O_3-doped Fe_2O_3 based Au particle size remained in a range of 30-50 nm, which is smaller than that of the Fe_2O_3 grains that were not doped with Al_2O_3. N_2 adsorption-desorption measurements showed that Al_2O_3 doping resulted in a stable mesoporous structure for the catalysts and remained a higher specific surface area, which promoted the thermal stability of the support. XRD and TG-DSC results indicated that Al_2O_3 doping retarded the crystallization of the support and consequently inhibited the growth of gold particles during high-temperature calcination. Low temperature CO oxidation was used as a probe reaction to evaluate the catalytic activity. Even when calcined at 500℃ for 12 h, the catalyst with Al_2O_3 doping achieved complete CO conversion at 26.7℃ while the lowest temperature of the complete CO conversion (T_(100)) of the catalyst without Al_2O_3 doping was as high as 61.6℃. Apparently, thermal stability is enhanced considerably by Al_2O_3 doping.关键词
纳米结构金催化剂/氧化铁载体/热稳定性/Al_2O_3/CO低温氧化Key words
Nano-structured gold catalyst/Ferric oxide support/Thermal stability/Al_2O_3/CO oxidation at low-temperature分类
化学化工引用本文复制引用
刘瑞辉,张存满,马建新..具有良好热稳定性的Al_2O_3改性Fe_2O_3基金催化剂[J].物理化学学报,2009,25(11):2261-2269,9.基金项目
同济大学汉高教席资助(081591) （081591）
