The reaction pathways and kinetics for the selective deposition of palladium on copper from the metalorganic precursor Pd(hfac)(2) have been established by means of reactive molecular beam-surface scattering where a flux of Pd(hfac)2 (ranging from 10(13) to 10(14) molecules cm(-2) s(-1)) impinges continuously on the copper surface. The surface selectivity of the deposition process is a consequence of a "redox transmetalation" reaction, which is best described by the stoichiometric equation Pd(hfac)(2) + Cu --> Pd + Cu(hfac)(2). On polycrystalline copper foils, the production and subsequent desorption of Cu(hfac)a from the surface occurs with unit efficiency at temperatures between 400 and 600 K. At temperatures above 600 K, the yield of Cu(hfac)(2) decreases and eventually falls to zero at 800 K as the thermolytic decomposition of the hfac ligands on the surface becomes kinetically competitive.