In this overview, we present some of our more fundamental approaches for making new and/or improved catalysts. First, the effect of mono atomic steps is discussed both in relation to the mechanism of the ammonia synthesis, and in terms of relevance for other reactions, such as the steam reforming and methanization processes. The possibility for utilizing steps to improve selectivity is also discussed. It is shown how micro kinetic modelling can be used to predict how the catalyst for the WGS reaction could be improved. Furthermore, an experimental technique is demonstrated. where alloys consisting of up to four metals can be tested under realistic conditions without loosing the ability to study the catalysts with Surface science techniques both prior to and after they have been Subjected to reaction conditions. Finally, the importance of in situ measurements will be demonstrated for some preliminary investigations of systems of relevance to fuel cell technology. (c) 2004 Elsevier B.V. All rights reserved.