Detailed studies of elementary chemical processes on well-characterize
d single crystal surfaces have contributed substantially to the unders
tanding of heterogeneous catalysis. insight into the structure of surf
ace alloys combined with an understanding of the relation between the
surface composition and reactivity is shown to lead directly to new id
eas for catalyst design, The feasibility of such an approach is illust
rated by the synthesis, characterization, and tests of a high-surface
area gold-nickel catalyst for steam reforming.