金属掺杂对六铝酸镧的结构及甲烷催化燃烧性能的影响

在TX-100/正己醇/环己烷组成的反相微乳液体系中,采用反相微乳-共沉淀法制备了系列单相金属掺杂(M为一种金属)和复合金属(M为两种或两种以上金属)掺杂的六铝酸镧(LaMxAl12-xO19)催化剂。用BET、XRD、SEM进行了物性表征,以甲烷燃烧为探针反应考察了催化剂的催化活性,分析了不同的离子取代Al3 对六铝酸镧的比表面积和活性的影响。结果表明:单金属Mn的存在可以降低甲烷的起燃温度,使催化剂具有良好的低温活性,且Mn的最佳掺杂数为1;单金属Fe掺杂的六铝酸镧催化剂具有较低的完全转化温度;而Fe、Mn共同掺杂的LaMnFeAl10O19催化剂具有优越的低、高温活性和高温稳定性。

Doping effect on configuration and catalytic performance of La-hexaaluminate

Single metal and multiple metals doped La-hexaaluminate were synthesized by reverse microemulsion in the system of water / Triton X-100 / n-hexanol / cyclohexane.The effects of doped elements on the phase,specific surface area and activity for methane combustion were investigated by means of XRD and BET.The results indicated that among LaMxAl12-xO19 catalysts,the catalyst with a Mn iron(x=1) was the best,The introduction of single Mn could improve the catalytic activity at a low temperature and make methane light-off temperature shift to a lower value;Single Fe doped La-hexaaluminate could make methane completely convert at a lower temperature;Fe and Mn doped La-hexaaluminate had the highest activity at both low temperature and high temperature;The stability of LaMnFeAl10O19 at a high temperature was also excellent.