Cobalt (30%wt.) oxide catalysts supported over ceria-modified (3-18%wt.) alumina supports were examined for the combustion of lean methane. The prepared samples were characterised by wavelength dispersive X-ray fluorescence, N₂ physisorption, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, temperature-programmed reduction with hydrogen and temperature-programmed reaction with methane. A significant enhancement of the activity was evidenced with respect to the catalyst supported over bare alumina, with an optimal cerium loading of 12%wt. and a resultant T₅₀ value of 480 °C. The ceria modification was found to induce a dual positive effect on the performance of the cobalt catalysts. On one hand, it acted as a physical barrier between deposited cobalt and alumina, thus inhibiting the cobalt-alumina interaction and the subsequent cobalt aluminate formation. On the other hand, the insertion of cerium ions in the spinel lattice led to a distortion of the structure that in turn resulted in an enhanced mobility of the oxygen species. The optimised catalyst exhibited a relatively good thermal stability for prolonged reaction time intervals (150 h) under dry conditions. The presence of water vapour markedly affected the catalytic performance although this negative effect was partially reversible.

检查了负载在二氧化铈改性的（3-18％wt。）氧化铝载体上的钴（30％wt。）氧化物催化剂的贫甲烷燃烧。通过波长色散X射线荧光，N ₂物理吸附，X射线衍射，拉曼光谱，X射线光电子能谱，透射电子显微镜，氢的程序升温还原以及与甲烷的程序升温反应来表征所制备的样品。对于负载在裸露的氧化铝上的催化剂，活性的显着提高被证明，铈的最佳载量为12％wt。和结果T ₅₀值480°C。发现二氧化铈改性对钴催化剂的性能产生双重积极影响。一方面，它充当沉积的钴和氧化铝之间的物理屏障，从而抑制了钴-氧化铝的相互作用以及随后的铝酸钴的形成。另一方面，铈离子在尖晶石晶格中的插入导致结构变形，进而导致氧物种的迁移率提高。优化的催化剂在干燥条件下延长的反应时间间隔（150 h）表现出相对较好的热稳定性。水蒸气的存在显着影响了催化性能，尽管这种负面影响是部分可逆的。