Promotional effects of samarium on Co3O4 spinel for CO and CH4 oxidation

• Published in: Journal of rare earths Vol. 32; no. 2; pp. 159 - 169
• Main Author: 徐香兰 韩红 刘建军 刘文明 李文龙 王翔
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.02.2014
• Subjects: CH4氧化; CO and CH4 oxidation; Co3O4; CO氧化; rare earths; SmCoO3; water vapor effect; X-射线粉末衍射; 催化剂制备; 四氧化三钴; 宣传效果; 尖晶石; 甲烷氧化活性; SmCoO3; CO and CH4 oxidation; water vapor effect; Co3O4; rare earths
• ISSN: 1002-0721; 2509-4963
• DOI: 10.1016/S1002-0721(14)60046-6

A series of CO3O4 spinel catalysts modified by Sm were prepared by co-precipitation method and tested for CH4 and CO oxidation. The addition of a small amount of Sm into Co3O4 led to an improvement in the catalytic activity for both reactions. Co0.98Sm0. 02 and Co0.95Sm0.05, the two samples with Co/Sm molar ratio of 0.98/0.02 and 0.95/0.05 in sequence, showed the similar and the highest activity for CH4 oxidation, with CH4 complete conversion at 450 ℃. In contrast, Coo.90Smo l0 was the most active sample for CO oxidation, with CO complete conversion at 120 ℃. The catalysts were characterized by techniques of N2 adsor- tion-desorption with Brunauer-Emmett-Teller technique （N2-BET）, X-ray powder diffraction （XRD）, thermal gravity analy- sis-differential scanning calorimetry （TGA-DSC）, Hz temperature programmed reduction （H2-TPR） and X-ray photoelectron spec- troscopy analysis （XPS）. Compared with pure Co3O4, for CO1-xSmx catalysts with 0.02≤x≤0.10, the addition of a small amount of Sm resulted in the formation of spinel Co3O4 and amorphous SmCoO3, hence increasing the number of Co3＋ and the active surface oxygen species, which was responsible for the improvement of the activity. C00.95Sm0.05 catalyst showed not only high thermal stability and activity but also good reaction durability in the presence of 5% water vapor for CH4 oxidation.