A series of La2O3 samples were prepared under different conditions. The hydrogen exchange reaction between CH4 and CD4 was chosen as test reaction to measure the activity of splitting C-H bond on La2O3. The NH3-TPD, CO2-TPD and poisoning experiments were carried out to study the acidic sites and the active sites on La2O3. The surface structure composition (O/La ratio) was measured by XPS. It was found that although being minor component of active sites, the acidic sites are also essential for the cleavage of C-H bond of CH4. The acidic sites and basic sites composing the active sites are probably a part of lattice La3+ and O2- ions, which show enough strength of acidity and basicity, resp. The formation of vacancies in La2O3 crystal can make more lattice ions become active sites.

Key words: METALLIC OXIDE CATALYST, ACTIVITY, METHANE, CHEMICAL BONDS, LANTHANUM OXIDE, ACID CENTER