The thesis of this review is that new catalytic concepts may be derived or discovered from new materials or newly recognized material properties. This thesis is demonstrated by a brief discussion of four materials, and the associated concepts, which enjoyed a certain fashion in the Journal of Catalysis and became themes of the author's research. The four materials (or material properties) described are restricted to platinum (exemplary in most cases) supported on TiO2, yttrium-stabilized zirconia, L-zeolite, and the mesoporous molecular sieve, MCM-41. While it was not recognized at the time, nor was it the driving force for the author's interest, all four materials can be shown to alter catalysis by a kind of metal-support interaction that, in part or entirely, underlies the concept that is being illustrated. Thus, the common metal Pt and the emphasized catalytic property, interaction between a metal particle and an oxide support, are used as the glue to hold together a discussion of otherwise disparate catalytic systems whose selection was dictated by the interests of the author. (C) 2003 Elsevier Science (USA). All rights reserved.