A method for preparing an acid catalyst having a long shelf-life is provided comprising doping crystalline iron oxides with lattice-compatible metals and heating the now-doped oxide with halogen compounds at elevated temperatures. The invention also provides for a catalyst comprising an iron oxide particle having a predetermined lattice structure, one or more metal dopants for said iron oxide, said dopants having an ionic radius compatible with said lattice structure; and a halogen bound with the iron and the metal dopants on the surface of the particle.
CONTRACTUAL ORIGIN OF THE INVENTION
The U.S. Government has rights in this invention pursuant to the employer-employee relationship of the Government to some of the inventors as U.S. Department of Energy employees at the Pittsburgh Energy Technology Center, and pursuant to 42 U.S.C. 5908 in respect to the inventor-employees of the Bayer Corporation.