SULFUR TRIOXIDE DECOMPOSITION CATALYST, SULFUR DIOXIDE PRODUCTION PROCESS USING SULFUR TRIOXIDE DECOMPOSITION CATALYST, HYDROGEN PRODUCTION PROCESS USING SULFUR DIOXIDE PRODUCTION PROCESS, AND PROCESS FOR PRODUCING SULFUR TRIOXIDE DECOMPOSITION CATALYST
A sulfur trioxide decomposition catalyst includes: a composite oxide containing an alkali metal and vanadium; and a catalyst support on which the composite oxide is supported. In addition, a process for producing a sulfur trioxide decomposition catalyst includes: impregnating the catalyst support with one solution of a solution containing an alkali metal compound and a solution containing a vanadium compound, and drying and preliminarily calcining the catalyst support; and impregnating the preliminarily calcined catalyst support with the other solution of the solution containing the alkali metal compound and the solution containing the vanadium compound, and drying and calcining the catalyst support.