More than 20 years ago. Christopher Master used the term gentle -skill-full - art to define homogeneous catalysis. In the present paper, we show that with the advances of knowledge of heterogeneous catalysis (CeO2-ZrO2,mixed oxides being taken as an example), this term call nowadays appropriately apply to heterogeneous catalysis as well. Thus, comprehension of the reaction mechanism and the appropriate choice of textural properties appear to allow true design of the properties of these catalytic nanomaterials, in a similar fashion to the way in which ligands gently modify the activity of a metal centre in a homogeneous catalyst. (c) 2004 Elsevier B.V. All rights reserved.