A simple way to control supported Pt nanoparticle size is demonstrated in this paper. By varying chloride or nitrate weight loading during the synthesis of catalysts via the method of charge enhanced dry impregnation (CEDI), Pt particles can be grown from about 1-10 nm. Size control was demonstrated over SiO2, Al2O3, Al-doped mesoporous silica, TiO2, and carbon supports. Sizes were verified by consistent XRD, chemisorption, and STEM measurements. Carbon, silica, and Al-doped silica are most sensitive to chloride-induced precursor sintering, while alumina and titania are least sensitive. (C) 2016 Elsevier B.V. All rights reserved.