Ce掺杂对Co基LDO臭氧催化剂的效能影响研究

Effects of Ce doping on the performance of Co-LDO ozone catalyst

钴基层状双金属氧化物(Co-LDO)是一类具有催化臭氧而实现苯胺深度降解功能的类水滑石型催化剂;铈(Ce)作为一种稀土元素,其掺杂对金属氧化物类催化剂性能提升方面一直是研究的热点。而从晶体结构改变的方式评判Ce掺杂对Co-LDO类臭氧催化剂效能影响的报道极为少见。为此,以两种不同Co-LDO类催化剂为掺杂对象制备了不同比例Ce掺杂的Ce@Co/Fe-LDO和Ce@Co/Al-LDO两类臭氧催化剂,通过XRD测试和苯胺降解测试共同探讨Ce掺杂对Co-LDO晶体结构与催化效能之间的关系。结果表明:在Co∶[Fe(Al)+Ce]摩尔比为3∶1的情况下,Ce取代铁或铝元素掺杂方式可提升LDO晶体结晶度并具有提高催化效能的作用,但在Co∶Fe(Al)摩尔比为3∶1时Ce的额外掺杂对LDO催化剂结晶度和效能上有抑制作用。

As a typical hydrotalcite-like catalyst,Co-based layered double-metallic oxide(Co-LDO)possesses a great capability in catalyzing ozone for the deep degradation of aniline;as a rare earth element,cerium(Ce)doping has been a research hotspot in improving the performance of metal-oxide catalysts.However,the effect of Ce doping on the performance of Co-LDO ozone catalysts from the perspective of the change of the crystal structure has been rarely reported.Therefore,various ratios of Ce doping were applied in the preparation of two different Co-LDO catalysts,i.e.,Ce@Co/Fe-LDO and Ce@Co/Al-LDO.The effect of Ce doping on the crystal structure and catalytic activity of Co-LDO is investigated by XRD and aniline degradation tests.The results show that in the case of m(Co)∶m([Fe(or Al)+Ce])=3∶1,the Ce doping Co-LDO catalysts,i.e.Ce@Co/Fe-LDO and Ce@Co/Al-LDO,can enhance the crystallinity and improve the catalytic efficiency,while the doping of Ce under the constant ratio of m(Co)∶m(Fe or Al)=3∶1 can inhibit the crystallinity and catalytic efficiency of LDO catalysts.