Catalyst Design for Selective Hydrogenation of Benzene to Cyclohexene through Density Functional Theory and Microkinetic Modeling

Cyclohexene is a chemical intermediate
produced through catalytic
partial hydrogenation of benzene. Density functional theory calculations
and microkinetic modeling (MKM) are used to illustrate that the binding
energy of benzene is a predictor of a catalyst’s cyclohexene
selectivity. Brønsted–Evans–Polanyi (BEP) and scaling
correlations are developed to correlate elementary reaction energetics
on 3-fold active metal ensemble sites. Based on thermochemical linear
relationships and BEP correlations, only benzene binding energies
and H2 dissociation energies are needed in MKM to predict
benzene hydrogenation activity and selectivity. MKM demonstrates that
an intermediate benzene binding energy leads to an optimal balance
of activity and selectivity toward cyclohexene formation. Uncertainties
in the slope and intercept of BEP and scaling relationships, estimated
by a Bayesian inference approach, were propagated in the MKM to quantify
uncertainty in catalytic performance. Ni5Ga3 and Ni3Ga intermetallic compounds are predicted to be
highly selective catalysts for benzene hydrogenation to cyclohexene.