  Recently, the solid-state frustrated Lewis pairs (FLPs) on the surface of
CeO2 have been demonstrated to effectively catalyze the selective hydrogenation
of unsaturated substrates, hence, the relationship between their intrinsic
properties and H2 activation at the atomic scale has attracted great attention.
In this work, the effects of Cu doping on the intrinsic FLPs properties for
different facets of CeO2 is investigated by using density functional theory
calculations, including the geometric parameters between Lewis acid-base
centers, and the reactivity of Lewis acid-base towards H2 activation. The study
demonstrates that introducing O vacancies on different crystal facets of CeO2
creates FLPs with the ability to efficiently cleavage hydrogen molecules. After
the substitution of Ce with Cu, the inadequate electron availability of Cu to
bond with O contributes to a reduction in the formation energy of O vacancies.
Importantly, Cu exert an influence not only on the intrinsic properties of FLPs
but also on the formation of new Ce-O and Cu-O FLPs. Considering the H2
activation, the doping of Cu results in an enhancement for the thermodynamics
by decreasing the reaction energies, while a hinderance for the kinetics by
increasing the energy barriers. Overall, with these theoretical investigations,
we propose certain hints for the future experimental studies concerning the
synthesis of Cu doped CeO2 catalysts for the H2 activation and hydrogenation
reactions.
