运用 AES,XPS,XRD和 TEM等手段研究了 La Co O3模型催化剂 SO2 中毒过程表面化学状态、晶相结构及表面形貌的变化状况 ,初步推断了 La Co O3钙钛矿型复合金属氧化物催化剂的 SO2 中毒机理 .在 SO2强化中毒过程中 ,SO2 与催化剂的活性组...运用 AES,XPS,XRD和 TEM等手段研究了 La Co O3模型催化剂 SO2 中毒过程表面化学状态、晶相结构及表面形貌的变化状况 ,初步推断了 La Co O3钙钛矿型复合金属氧化物催化剂的 SO2 中毒机理 .在 SO2强化中毒过程中 ,SO2 与催化剂的活性组分 La Co O3反应生成硫酸镧和氧化亚钴 ,而在催化剂膜层内部则生成硫酸镧、亚硫酸镧及氧化亚钴 . SO2 对活性组分层的侵入及硫与 La Co O3活性组分的反应破坏了催化剂的钙钛矿结构 ,使得催化剂彻底中毒 .当中毒温度较低及中毒时间较短时 ,硫在膜层中呈峰形分布 ,其浓度随中毒温度及时间的增加而增加 .随中毒温度的升高及中毒时间的增长 ,由于亚硫酸盐的分解作用 ,S在活性层中的浓度反而降低 ,中毒深度则继续增加 .展开更多
A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）,...A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, energy dispersive X-ray spectrometer （EDX）, and laser Raman spectroscopy （LRS）. The resuks showed that modulating the growth parameters, such as the addition of surfactants as well as the adding manner of the precipitator had a significant effect on the overall shape and size of the obtained nanocrystals. The nanorods with the diameter of 20 nm and spherical LaCoO3 nanocrystals with the size of about 25 nm could be obtained at a relatively low calcining temperature of 600℃. Furthermore, the Raman properties of LaCoO3 products obtained at different calcining temperatures were investigated.展开更多
文摘运用 AES,XPS,XRD和 TEM等手段研究了 La Co O3模型催化剂 SO2 中毒过程表面化学状态、晶相结构及表面形貌的变化状况 ,初步推断了 La Co O3钙钛矿型复合金属氧化物催化剂的 SO2 中毒机理 .在 SO2强化中毒过程中 ,SO2 与催化剂的活性组分 La Co O3反应生成硫酸镧和氧化亚钴 ,而在催化剂膜层内部则生成硫酸镧、亚硫酸镧及氧化亚钴 . SO2 对活性组分层的侵入及硫与 La Co O3活性组分的反应破坏了催化剂的钙钛矿结构 ,使得催化剂彻底中毒 .当中毒温度较低及中毒时间较短时 ,硫在膜层中呈峰形分布 ,其浓度随中毒温度及时间的增加而增加 .随中毒温度的升高及中毒时间的增长 ,由于亚硫酸盐的分解作用 ,S在活性层中的浓度反而降低 ,中毒深度则继续增加 .
基金Project supported by the Postdoctoral Foundation of China (20060390284)Jiangsu Planned Projects for Postdoctoral Research Funds
文摘A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, energy dispersive X-ray spectrometer （EDX）, and laser Raman spectroscopy （LRS）. The resuks showed that modulating the growth parameters, such as the addition of surfactants as well as the adding manner of the precipitator had a significant effect on the overall shape and size of the obtained nanocrystals. The nanorods with the diameter of 20 nm and spherical LaCoO3 nanocrystals with the size of about 25 nm could be obtained at a relatively low calcining temperature of 600℃. Furthermore, the Raman properties of LaCoO3 products obtained at different calcining temperatures were investigated.
