structure

of a catalyst
The distribution in space of the atoms or ions in the material part of the catalyst and, in particular, the distribution at the surface.
Source:
PAC, 1976, 46, 71 (Manual of Symbols and Terminology for Physicochemical Quantities and Units - Appendix II. Definitions, Terminology and Symbols in Colloid and Surface Chemistry. Part II: Heterogeneous Catalysis) on page 79