College of Science & Engineering
Catalytic science will play a critical role in developing alternative energy sources and new conversion technologies for the 21st century. This group's objective for this project is to understand the origin of distinct olefin and methoxyl hydrogenation reactivity trends across a range of acidic molecular sieve catalysts (e.g. zeolites) which impact the selectivity, activity, and stability of these catalysts during methanol-to-hydrocarbons (MTH) synthesis. The chemical and steric confining environments within each of these microporous catalytic materials requires density-functional theory (DFT) calculations to determine thermodynamically and kinetically relevant energies during the catalytic hydrogenation of olefins and methoxyl. Zeolitic acid strength affects both adsorption/desorption energies and transition state energies - therefore playing a key role in controlling thermodynamic and kinetic aspects of the hydrogenation reaction pathway. These researchers wish to rigorously understand the effect of acid strength and chemical composition on the hydrogenation of olefins and methoxyls under MTH relevant conditions using MSI. Specifically, they are using computational tools for:
- Calculation of deprotonation energies on materials of different acid strength using Gaussian software implemented in MSI
- Determination of mechanistic pathways and calculations of energies of ground and transition states involved in olefins and methoxyl hydrogenation on Bronsted acid sites as a function of DFT-calculated deprotonation energy (DPE)
The project is significant because high-pressure H2 co-feeds are an industrially-relevant strategy for mitigating deactivation during MTH catalysis and may be improved by fundmental trends in zeolitic acid strength and hydrogenation activity discovered in this study. This integrated experimental and theoretical approach lies at the crossroads of materials synthesis, computational catalysis, and catalytic chemistry and aims to advance our ability to understand, design, and control chemical transformations using catalysis.