This book is devoted to the emerging field of techniques for visualizing atomic-scale
properties of active catalysts under actual working conditions i.e. high gas pressures and
high temperatures. It explains how to understand these observations in terms of the surface
structures and dynamics and their detailed interplay with the gas phase. This provides an
important new link between fundamental surface physics and chemistry and applied catalysis.
The book explains the motivation and the necessity of operando studies and positions these
with respect to the more traditional low-pressure investigations on the one hand and the
reality of industrial catalysis on the other.The last decade has witnessed a rapid development
of new experimental and theoretical tools for operando studies of heterogeneous catalysis. The
book has a strong emphasis on the new techniques and illustrates how the challenges introduced
by the harsh operando conditions are faced for each of these new tools. Therefore one can
also read this book as a collection of recipes for the development of operando instruments. At
present the number of scientific results obtained under operando conditions is still limited
and mostly focused on a simple test reaction the catalytic oxidation of CO. This reaction thus
forms a natural binding element between the chapters linking the demonstrations of new
techniques and also connecting the theoretical and experimental studies. Some first results on
other reactions are also presented. If there is one thing that can be concluded already in this
early stage it is that the catalytic conditions themselves can have dramatic effects on the
structure and composition of the surfaces of catalysts which in turn can greatly affect the
mechanisms the activity and the selectivity of the chemical reactions that they catalyze.
