The invention relates to a nickel hexaaluminate-comprising catalyst for reforming hydrocarbons, preferably methane, in the presence of carbon dioxide, which comprises hexaaluminate in a proportion in the range from 65 to 95% by weight, preferably from 70 to 90% by weight, and a crystalline, oxidic secondary phase selected from the group consisting of LaAlO3, SrAl2O4 and BaAl2O4 in the range from 5 to 35% by weight, preferably from 10 to 30% by weight. The BET surface area of the catalyst is ≧5 m2/g, preferably ≧10 m2/g. The molar nickel content of the catalyst is ≦3 mol %, preferably ≦2.5 mol % and more preferably ≦2 mol %. The interlayer cations are preferably Ba and/or Sr. The process for producing the catalyst comprises the steps: (i) production of a mixture of metal salts, preferably nitrate salts of Ni and also Sr and/or La, and a nanoparticulate aluminum source, (ii) molding and (iii) calcination. The catalyst of the invention is brought into contact with hydrocarbons, preferably methane, and CO2 in a reforming process, preferably at a temperature of >800° C. The catalyst is also distinguished by structural and preferred properties of the nickel, namely that the nickel particles mostly have a tetragonal form and the particles have a size of ≦50 nm, preferably ≦40 nm and particularly preferably ≦30 nm, and are present finely dispersed as grown-on hexaaluminate particles. The catalyst has only a very low tendency for carbonaceous deposits to be formed.