Nanocatalysis is one of the most exciting subfields to have emerged from nanoscience. Its central aim is the control of chemical reactions by changing the size, dimensionality, chemical composition and morphology of the reaction center and by changing the kinetics using nanopatterning of the reaction centers. This opens up new avenues for atom-by-atom design of nanocatalysts with distinct and tunable chemical activity, specificity, and selectivity. This book is intended to give a pedagogical and methodological overview of this exciting and growing field and to highlight specific examples of current research. In this way it serves both as a textbook for graduate students who plan to enter the field and as a reference work for scientists already active in this and related areas.