(472a) Methanol Synthesis From CO2 - Experiment and Theory
The active site of the industrial methanol synthesis catalyst Cu/ZnO/Al2O3 is identified with a combined experimental and theoretical study. We investigate the reaction mechanism of both, CO and CO2 hydrogenation, on this site using density functional theory calculations. In combination with microkinetic modeling, the kinetics of CO and CO2 hydrogenation are described and we are able to shed some light on some of the open questions of methanol synthesis. We extend the analysis over a range of different transition metals and simplify adsorption and transition state energies using scaling relations between different adsorbates on surfaces. This enables us to describe CO2 hydrogenation using simple descriptors and allows for the construction of activity volcanos for these two hydrogenation processes. Based on the activity volcanos we identified new catalyst leads based on Ni and Ga for the CO2 hydrogenation to methanol at ambient pressure. Experiments showed that these catalysts are indeed selective and active for this process.