A hexaaluminate-containing catalyst containing a hexaaluminate-containing phase which includes cobalt and at least one further element of La, Ba or Sr. The catalyst contains 2 to 15 mol % Co, 70 to 90 mol % Al, and 2 to 25 mol % of the further element of La, Ba or Sr. In addition to the hexaaluminate-containing phase, the catalyst can include 0 to 50% by weight of an oxidic secondary phase. The process of preparing the catalyst includes contacting an aluminum oxide source with cobalt species and at least with an element from the group of La, Ba and Sr. The molded and dried material is preferably calcined at a temperature greater than or equal to 800° C. In the reforming process for reacting hydrocarbons in the presence of CO2, the catalyst is used at a process temperature of greater than 700° C., with the process pressure being greater than 5 bar.