CO2 Hydrogenation to CH3OH on Metal-Doped TiO2(110): Mechanisms, Strain
Effect and A New Thermodynamic-Kinetic Relation
Abstract
To develop low temperature catalysts for CO2 to methanol, CO2
hydrogenation to methanol on Znx@TiO2(110) (x = 0-2) was explored using
density functional calculations and microkinetic simulations. The
reaction mechanisms on the three model systems were determined and it is
shown that Zn2@TiO2(110) is most active. The most favorable pathway on
Zn2@TiO2(110) is identified and CO2 + H to HCOO is found to be the
rate-controlling step. It is demonstrated that there is a linear
relation (named AEB relation) between the adsorption energies of the
initial states and the barriers for the controlling step on the 17
systems studied. Calculations on strained surfaces show that the AEB
relation exists within ±1% strain, which is an effective way to improve
catalytic activity. Sr2@TiO2(110) and -1% strained CaZn and ZnCu doped
TiO2(110) are potential good low temperature catalysts and deserve
experimental testing.