A support for a catalyst for controlling vehicular exhaust emissions comprising a high surface area refractory metal oxide, e.g., gamma-alumina, having a monomolecular layer of a second oxide selected from the group consisting of titanium dioxide, cerium dioxide and zirconium dioxide. Typically, the monomolecular layer will have a thickness of less than about 10 angstroms. The support may be converted into a vehicular exhaust emission control catalyst by depositing the support on a substrate such as cordierite depositing a precious metal component such as platinum on at least part of the monomolecular layer. Preferably, the catalyst will also contain at least one NO_x storage component deposited on at least part of the monomolecular layer. Catalysts prepared using the catalyst supports of the invention exhibit outstanding thermal stability and resistance to sulfur poisoning.