NOVELTY - A shift catalyst comprises oxide(s) of aluminum, silicon, phosphorus, and/or vanadium; a porous body of titanium dioxide to which the oxide(s) are added; and platinum supported by the porous body of titanium dioxide.    USE - As catalyst for a shift reaction that produces H2 and CO2 from CO and H2O. The hydrogen generated from the shift reaction can be used as fuel of fuel cell.    ADVANTAGE - The inventive catalyst has improved heat resistance, exhibits high CO reduction rate, and reduces the capability deterioration under high space velocity condition.    DETAILED DESCRIPTION - A shift catalyst for a shift reaction that produces hydrogen gas (H2) and carbon dioxide (CO2) from carbon monoxide (CO) and water (H2O) comprises oxide(s) of aluminum (Al), silicon (Si), phosphorus (P), and/or vanadium (V); a porous body of titanium dioxide (TiO2) to which the oxide(s) are added; and platinum (Pt) supported by the porous body of titanium dioxide.    INDEPENDENT CLAIMS are also included for;    (1) A method of producing the inventive shift catalyst by (a) mixing a liquid or gel-form raw material of TiO2 containing Ti and a liquid or gel-form raw material of the oxide, (b) baking the mixture, (c) forming a porous body of the mixture, and adsorbing and supporting Pt on the porous body. It can also be produced by forming a porous body of TiO2; impregnating the pores of the porous body with a solution comprising salt(s) of Al, Si, P, S, and/or V; heating the impregnated porous body; and supporting Pt on the porous body.    (2) A reactor for conducting the shift reaction comprising the inventive shift catalyst retained by a retainer member;    (3) A fuel cell system comprising a reformer portion, a shift portion and a fuel cell, where the shift portion contains the inventive shift catalyst; and    (4) A method of converting raw material to electric power using the fuel cell system in (C), where the raw material is converted to electric power by (i) subjecting the raw material to a reforming reaction in the reformer portion of the fuel cell system to produce a reformed gas comprising carbon hydrogen rich gas; (ii) introducing the reformed gas into the shift portion of the fuel cell system so that the reformed gas undergoes shift reaction; and (iii) generating electric power in the fuel cell using the reformed gas from the shift portion.