Single metal atom deposited on an appropriate substrate can lead to highly economical,efficient,and selective catalysis.One of the greatest challenges is to control the electronic metal-support interactions(EMSI)between the supported metal atom and the substrate so as to optimize the catalytic effect.Here,from first-principles calculations,we show that an otherwise inactive Pd single adatom on TiO2(110)can be tuned into a highly effective catalyst,e.g.for O2 adsorption and CO oxidation,by purposefully selected metalnonmetal co-dopant pairs in the substrate.