Method for preparing water gas shift catalysts, catalysts and process for reducing carbon monoxide content

A method for preparing a water gas shift catalyst, the method comprising the following steps:

• 1) coprecipitating a solution containing a soluble iron salt, a soluble platinum compound and optionally a soluble aluminum salt, in a first polar solvent, with a soluble sodium salt to form a suspension comprising a precipitate,
• 2) maintaining the pH of the suspension between 7.5 and 8.0, under stirring, and at a temperature between 20 and −80 degrees Centigrade (° C.), followed by aging of the suspension at said pH under stirring and at the temperature between 2° and 80° C. for 0.5 to 2.0-hours (h);
• 3) filtering and washing the precipitate formed with a second polar solvent until a residual sodium content of the precipitate is between 0.11 and 0.3% weight in weight (w/w);
• 4) drying the precipitate obtained at a temperature between 60° C. and 150° C. for 1 to 6 h, followed by calcination between 300° C. and 400° C., for 1 to 5 h to form a material;
• 5) formatting the material to obtain catalyst tablets and, then, calcinating at a temperature between 300° C. and 450° C. to obtain hematite promoted with platinum and sodium and, optionally, with aluminum.