Remote Activation of Chemical Bonds in Heterogeneous Catalysis

Abstract

A catalyst is generally considered to act locally at the reaction site. For heterogeneous catalysis, this concept should be extended to include the influence of the surface on the nonreacting regions of the reactants because this can lead to more favorable reaction paths. In this work, density functional theory is used to examine how a Pt(111) surface hydrogenates the ketone 2,2,2-trifluoroacetophenone (TFAP). It is revealed that the platinum activates TFAP through an interaction with a part of the molecule remote from the reaction while simultaneously mediating the hydrogenation of the carbonyl. The remotely activated state is formed through double bond migration enabled by the malleable electronic structures of the chemisorbed phenyl ring and platinum surface. By forming an enol, the TFAP carbonyl is able to decoordinate from the Pt surface reducing steric and electronic interference that inhibits hydrogenation. This result illustrates the necessity of considering catalyst interactions with molecular pa...