ACTIVATION OF LA2O3 FOR THE CATALYTIC REDUCTION OF SO2 BY CO

Lanthanum oxide by itself has been reported to be inactive for the red uction of SO2 by CO; however, we discovered that La2O3 can be activate d in a reaction gas atmosphere if previously hydrated. The active phas e of the activated lanthanum oxide was identified to be lanthanum oxys ulfide by using X-ray diffraction. This showed that the activation was in essence a sulfidization of the oxide. An activation mechanism is p roposed based on the surface acidic and basic properties resulting fro m the dehydroxylation of the lanthanum hydroxide. (C) 1996 Academic Pr ess, Inc.