Comparative study of O-2 dissociation on various metalloporphyrins - art. no. 244719

摘要

We investigate O-2 interaction with various metalloporphyrins (MnP, FeP, CoP, and NiP ) using ab initio calculations based on density-functional theory. We discuss the trends in the activation barriers for the O-O bond cleavage in relation to the geometric, vibrational, electronic, and energetic properties of the systems. Whether the lowest unoccupied molecular orbital-highest occupied molecular orbital (LUMO-HOMO) levels of the metalloporphyrins involve the corresponding metal centers depends on the d orbital occupancies of the metals. We found that activation barriers for the O-2 dissociation can be mainly determined from the LUMO-HOMO characters of the metalloporphyrins, and consequently the FeP is the best catalyst with respect to the O2 interaction from adsorption to dissociation. (c) 2005 American Institute of Physics.