Theoretical study of conversion of ethanol to light olefins over ZSM-5

Abstract

The conversion of ethanol to ethylene and 1-butene on the H-ZSM-5, M-ZSM-5, M = Cu+, Ag+, Au+, Ni2+, Pd2+ and Pt2+ has theoretically been investigated using density functional theory (DFT) calculations. The configurations of interaction between adsorbate and catalysts at various cluster models were obtained using the B3LYP/LanL2DZ computations. The energetics, thermodynamic properties, rate and equilibrium constants for all the reaction steps were determined at 298.15 K compared to its reaction without catalyst. The rate constants for the ethanol conversion to ethylene over H-ZSM-5 and M-ZSM-5 catalysts are in decreasing order: Pt-ZSM-5 > Pd-ZSM-5 ≈ Au-ZSM-5 > Ag-ZSM-5 > H-ZSM-5 > Cu-ZSM-5 >> Ni-ZSM-5. The rate constants for the ethanol conversion to 1-butene over the M-ZSM-5 catalysts are in decreasing order: H-ZSM-5 >> Ni-ZSM-5 > Pd-ZSM-5 ≈ Pt-ZSM-5 ≈ Au-ZSM-5 > Ag-ZSM-5 > Cu-ZSM-5.