An Electrochemical Study of Frustrated Lewis Pairs: A Metal-Free Route to Hydrogen Oxidation

Frustrated
Lewis pairs have found many applications in the heterolytic
activation of H2 and subsequent hydrogenation of small
molecules through delivery of the resulting proton and hydride equivalents.
Herein, we describe how H2 can be preactivated using classical
frustrated Lewis pair chemistry and combined with in situ nonaqueous
electrochemical oxidation of the resulting borohydride. Our approach
allows hydrogen to be cleanly converted into two protons and two electrons
in situ, and reduces the potential (the required energetic driving
force) for nonaqueous H2 oxidation by 610 mV (117.7 kJ
mol–1). This significant energy reduction opens
routes to the development of nonaqueous hydrogen energy technology.