PARTIAL OXIDATION OF METHANE TO METHANOLOVER Mo/La-Co-OXIDE CATALYSTS

摘要

Direct and selective oxidation of methane to methanol (SOM) with O_2 is one of the most attractive challenge in catalysis and chemical engineering. Considerable effort has been devoted to developing effective catalysts so far, but poor CH_3OH selectivity and yield have been obtained on the most of catalysts. Generally speaking, higher CH_3OH selectivity and yield could be reached when using N_2O as oxidant instead of O_2. It is reason that N_2O easily produces O~- species, which are more reactive species responsible for the formation of CH_3OH than O~(2-) species . However, N_2O is too expensive and corrosive to be used as oxidant in industrial process of SOM. On the other hand, if SOM can be accomplished near natural gas field (at evaluated pessure), the cost of SOM process will greatly reduce. Therefore, it is necessary to further develop well-working catalysts in SOM with O_2 as oxidant at evaluated pressure. The pervosikite type oxide has high ability of activation of molecular oxygen, due to possessing lattice deficient sites. To our knowledge, the pervosikite oxide catalysts show good activity in combustion of methane, partial oxidation of methane to syngas and oxidative coupling of methane etc. Few research works on using pervosikite oxide as catalysts in SOM have been reported so far. Here, Mo/La-Co-Oxide catalysts were investigated and found to have excellent performance in SOM with O_2 as oxidant.