Ab initio molecular dynamics study of the hydrogen oxidation mechanism by Ni-based catalysts
EMSL Project ID
39701
Abstract
Abstract. Recent advances in transition-metal-based bio-inspired catalysts obtained in the Energy Frontier Research Center (EFRC) on "Molecular Electrocatalysis" (PI: Dr. Morris Bullock, PNNL) showed the possibility to generate H2 or to cleave H2 heterolytically with a proficiency approaching that of the hydrogenase enzymes. Herein, we propose a detailed atomistic study of the reaction steps of the hydrogen oxidation carried out by a novel class of Ni-based catalysts developed in the EFRC. In these complexes hydrogen activation involves the interaction of a dihydrogen species with pendant amine bases incorporated in a six-member ring, which act as proton relays. The catalytic cycle will be investigated by hybrid quantum mechanics/molecular mechanics simulations along with enhanced sampling techniques to reconstruct free-energy landscapes. Both solvent and counterions will be explicitly considered using atomistic empirical potentials, while the catalyst and the hydrogen molecule will be described within the density functional theory framework. We will try to characterize the factors tuning structural rigidity and flexibility of the ligand spheres and how these factors might facilitate the delivery of protons via bond breaking and formation. Catalytic pathways and intermediates will be verified against cyclic voltammetry measurements of catalytic currents and NMR measurements. All of the calculation will be carried out using the CP2K and the NWChem programs.
Project Details
Project type
Exploratory Research
Start Date
2010-04-22
End Date
2011-04-24
Status
Closed
Released Data Link
Team
Principal Investigator
Team Members