Fuel reformer, carbon monoxide selective methanation method, carbon monoxide selective methanation catalyst, and production method thereof

In fuel reforming, a catalyst that converts carbon monoxide to hydrogen by reacting carbon monoxide with hydrogen while suppressing methanation of carbon dioxide contained in hydrogen gas produced from various hydrocarbon fuels. In this selective methanation catalyst for carbon monoxide, the active component of the catalyst for methanation of carbon monoxide is at least one selected from halogen, an inorganic acid, and a metal oxyacid which are carbon dioxide reaction inhibitors. Adsorbed or bound.