Structure and Reactivity of Acetonitrile on Pt(111) and Graphene Substrates
EMSL Project ID
50810
Abstract
Acetonitrile is a widely used solvent in electrochemical systems and its behavior at electrode interfaces can affect the performance of batteries and energy storage devices. In some recent work on our EMSL proposal #49549 "Properties of Amorphous Solids and Supercooled Liquids near the Glass Transition: Models for liquids at Interfaces and in the Condensed Phase", we experimentally studied the desorption kinetics and structure of acetonitrile on a graphene and Pt(111) surface. Both of these materials are or are being considered for electrode materials in batteries and fuel cells. On graphene our experimental results suggest the acetonitrile is physiosorbed and lies flat on the surface. In contrast, on Pt(111) acetonitrile appears to lie perpendicular to the surface at low temperatures (< 90 K) but transitions to a configuration where it lies parallel to the substrate. We hypothesize that on Pt(111) acetonitrile chemisorbs to the surface with the N end of the molecule binding to a single Pt atom (the N-top configuration). At higher temperatures acetonitrile forms chemical bonds to two Pt atoms, one from the C and one from the N (?-2 configuration). This bonding arrangement forces the molecule to lie flat on the surface.To test this hypothesis, we would like to conduct theoretical calculations to get the relative binding energies for the N-top and ?-2 configurations. We would like to use the either the ADF and/or NWChem codes to do these calculations. We estimate that we would need 100K hours of compute time.
Project Details
Start Date
2019-03-14
End Date
2019-09-30
Status
Closed
Released Data Link
Team
Principal Investigator