Correlating Optical and Structural Properties of CO on Transition Metal Surfaces

TL;DR

This paper uses advanced theory to link optical and structural properties of CO on metal surfaces, improving predictions of CO behavior and aiding in understanding CO2 reduction.

Contribution

A new theoretical approach that correlates optical data with structural information to predict CO adsorbate behavior on transition metals.

Findings

The theory accurately predicts spectral features of CO on Pt(111) and Cu(111) at different coverages.

The method can infer structural details of CO from optical data, including potential OCCO dimers.

This approach complements DFT and addresses its limitations in predicting CO energetics.

Abstract

We present an optical
study based on the quasiparticle
self-consistent GW (QSGW) approximation
combining structural information taken from density functional theory
(DFT) to elucidate spectral features of CO adsorbed on Pt(111) and
Cu(111). Optical information and structural arrangement of the adsorbed
CO are correlated by varying both site positions and CO coverage as
compared to experimental studies (θ = 1/4 to θ = 1/2).
This enables us to resolve key spectral features of both occupied
and unoccupied molecular states at various adsorbate coverages, comparing
theory to experiment. Using experimental data as benchmarks, we show
the theory compares well with available data. Its predictive power
provides a new path to infer information about the structure of CO
from optical information and can help to predict the presence of other
little understood adsorbates such as an OCCO dimer that may be relevant
to mechanistic pathways for reduction of CO2 to high value
C2+ products. This new approach complements
total energy calculations and also fills a void in DFT-based theory
that is known to be an unreliable predictor of the energetics of CO
on transition metal surfaces.

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