We established a chemical modification strategy to search for a substitute of platinum toward O-2 activation. Achieving this required an understanding of the chemical bonding interactions along the corresponding reaction pathway. Using recently developed chemical bonding analysis schemes, we found that the transition state of O-2 dissociation on Pt(111) is stabilized by electrostatic interactions and the bonding interaction between the two oxygen atoms. This paves the way for tuning the O-2 activation barrier by replacing a surface atom with a less electronegative transition metal atom. We considered substituted Pd(111), Ag(111), and Au(111) surfaces and suggest some potential candidates for further screening by experimentalists. (C) 2008 Elsevier Inc. All rights reserved.