Taymaz TABARI
,
Haman TAVAKKOLI
催化学报
doi:10.1016/S1872-2067(11)60442-7
LaFe0.9Co0.1O3(LFCO) perovskite nanoparticles were prepared using a sol-gel method. The physical and chemical properties of the catalyst were determined using X-ray diffraction (XRD), transmission electron microscopy, scanning electron microscopy, scanning tun-neling microscopy, energy dispersive X-ray spectroscopy, thermogravimetric analysis, and Fourier transform infrared spectroscopy. The catalytic activity of the sample was evaluated using aerobic oxidation of thiols to disulfides. The XRD results indicated that the LFCO had a good crystalline phase at 750°C. The experimental data revealed that the LFCO particles were nano-sized. LFCO nanoparticles can catalyze the oxidation of various thiols, including aromatic and aliphatic thiols. The effects of reaction parameters such as temperature, solvent, and the amount of catalyst on the oxidation of 4-chlorothiophenol were investigated. In comparison with reactions using the corresponding neat complexes, i.e., Co(NO3)2·6H2O and Fe(NO3)3·9H2O, higher yields were obtained in the oxidation reaction catalyzed by LFCO nanoparti-cles.
关键词:
perovskite-type oxide
,
nanopowder
,
oxidation of thiols
,
sol-gel method
周嵬
,
薛小平
,
葛磊
,
郑尧
,
邵宗平
,
金万勤
无机材料学报
doi:10.3724/SP.J.1077.2007.00657
在EDTA-柠檬酸联合络合法制备LSCF复合氧化物的过程中, 利用浓硝酸对LSCF的固态前驱体进行处理, 实现前驱体低温自燃烧反应. 以H2O2分解作为模型反应考察不同制备条件对催化性能的影响到响. 通过系统研究固态前驱体水溶液的pH值和固态前驱体的FT-IR结果, 对其分解过程进行了, 并解释了自燃发生的原因. 通过XRD考察了初级粉体经高温焙烧后产物的晶体结构. 研究结果表明: 硝酸处理可以抑制LSCF晶粒生长, 并且提高LSCF的双氧水催化性能, 其中LSCF-40-900的催化性能最好.
关键词:
钙钛矿型氧化物
,
La0.6Sr0.4Co0.2Fe0.8O3-δ
,
HNO3 treatment
,
decomposition of peroxide hydrogen
杨晓龙
,
夏春谷
,
熊绪茂
,
慕新元
,
胡斌
催化学报
doi:10.1016/S1872-2067(09)60055-3
采用柠檬酸法合成了BaCeO_3和掺杂Y~(3+)的BaCe_(0.9)Y_(0.9)O_(3-δ)复合氧化物,以Ru_3(CO)_(12)为前体,利用浸渍法制备了Ru/BaCeO_3和Ru/BaCe_(0.9)Y_(0.1)O_(3-δ)催化剂.通过X射线衍射、扫描电镜和透射电镜技术对样品进行了表征,并在固定床反应器中考察了催化剂的氨合成反应活性.结果表明,载体BaCeO_3的稳定性优于BaCe_(0.9)Y_(0.1)O_(3-δ),但Ru/BaCe_(0.9)Y_(0.1)O_(3-δ)催化剂的氨合成活性明显高于Ru/BaCeO_3,在3.0MPa,15 000h~(-1),425℃反应时,Ru/BaCe_(0.9)Y_(0.1)O_(3-δ)催化剂上氨合成反应速率达到432.5ml/(g·h),是Ru/BaCeO_3催化剂的1.6倍.这种活性和稳定性的显著差异来自载体中Ce~(4+)与Ru纳米粒子间的电子作用.
关键词:
氨合成
,
钌
,
铈酸钡
,
钇
,
钙钛矿型氧化物
,
电子作用
