Group Additivity for Aqueous Phase Thermochemical Properties of Alcohols on Pt(111)

Despite progress in theoretical tools,
the influence of solvation
in heterogeneous catalysis remains poorly understood and predicted
due to the large computational burden. In this work, we show that
the inclusion of the solvation by water using a continuum model thermodynamically
inhibits the O–H bond scissions involved in the ethanol aqueous
phase reforming reaction over Pt(111), while it tends to favor the
C–H, C–C, and C–O scissions. Then, we present
a novel group additivity scheme for the free energy of adsorbates
at the Pt/water interface that is able to capture this solvent effect.
The mean absolute error (MeanAE) for the Gibbs free energy of formation
is 3.3 kcal/mol over the investigated set of 200 species at the interface
and the MeanAE for the 151 reaction free energies of ethanol aqueous
phase reforming is 2.8 kcal/mol. Regarding the effect of solvation,
our scheme is able to predict it with a MeanAE of about 1 kcal/mol.
Together, the scheme promises to be accurate enough for narrowing
down the most important reaction pathways in complex reaction networks
as encountered in biomass conversion.