This award supports an international workshop on progress in catalyst preparation to be held in Mar del Plata, Argentina, during the 7th through the 10th of October, 1991, with the participation of eight scientists from the U. S. and nine from Argentina. The workshop will cover the following three topics: 1) catalyst precursors and their method of addition, such as impregnation, precipitation, and ion exchange, 2) activation treatments, such as calcination, oxidation, and reduction, 3) modification of catalytic properties, such as surface modification by ion exchange, and bulk modification by metal substitution or complex inclusion. The workshop will be restricted to the types of catalysts extensively investigated in both countries, to favor discussion and further cooperation. Thus, the workshop will be mainly dedicated to supported metal and metal oxide catalysts, and modified molecular sieves and layered structures. Emphasis will be placed on the characterization of the preparation and modification steps and their influence upon catalytic properties. Recently a rapidly widening number of American researchers is becoming involved in this area. In Argentina the situation is similar where the school of catalysis is of American and European origin, and the Argentine work in catalyst preparation is significant. This workshop by bringing together scientists from Argentina and the U.S. will lead to further collaboration in catalysis which will increase productive output and benefit research in both countries.