Catalysts based on silver supported on foam ceramics and modified by Zr, Cc and La oxides have been studied in the process of partial oxidation of methanol to formaldehyde. The foam catalysts exhibit high catalytic, mechanical and fluidodynamic properties exceeding the characteristics of conventional crystalline and supported silver samples. Modifying additives of Zr and Cc oxides raise activity and selectivity of the supported foam-silver catalyst as well as its stability during the prolonged functioning. The modifiers change the electronic state and redox properties of silver, the metal dispersivity, surface diffusion and aggregation of silver during the long-term service. (C) 2004 Elsevier B.V. All rights reserved.