Critical Role of Thermal Fluctuations for CO Binding on Electrocatalytic Metal Surfaces.

This work considers the evaluation of density functional theory (DFT) when comparing against experimental observations of CO binding trends on the strong binding Pt(111) and intermediate binding Cu(111) and for weak binding Ag(111) and Au(111) surfaces important in electrocatalysis. By introducing thermal fluctuations using appropriate statistical mechanical NVT and NPT ensembles, we find that the RPBE and B97M-rV DFT functionals yield qualitatively better metal surface strain trends and CO enthalpies of binding for Cu(111) and Pt(111) than found at 0 K, thereby correcting the overbinding by 0.2 to 0.

Challenges for density functional theory: calculation of CO adsorption on electrocatalytically relevant metals.

Density Functional Theory (DFT) is currently the most tractable choice of theoretical model used to understand the mechanistic pathways for electrocatalytic processes such as CO or CO reduction. Here, we assess the performance of two DFT functionals designed specifically to describe surface interactions, RTPSS and RPBE, as well as two popular meta-GGA functionals, SCAN and B97M-rV, that have not been a priori optimized for better interfacial properties. We assess all four functionals against available experimental data for prediction of bulk and bare surface properties on four electrocatalytically relevant metals, Au, Ag, Cu, and Pt, and for binding CO to surfaces of these metals.

Electronic structure calculations permit identification of the driving forces behind frequency shifts in transition metal monocarbonyls.

We report the adiabatic energy decomposition analysis (EDA) of density functional theory (DFT) results, shedding light on the physical content of binding energies and carbon monoxide (CO) frequency (υCO) shifts in select first-row transition metal monocarbonyls (MCOs; M = Ti-, V-, Cr-, Co-, Ni-, Cu-, V, Cr, Mn, Ni, Cu, Zn, Cr+, Mn+, Fe+, Cu+, and Zn+). This approach allows for the direct decomposition of υCO, in contrast to previous studies of these systems. Neutral, anionic, and cationic systems are compared, and our results indicate that the relative importance of electrostatic interactions, intramolecular orbital polarization, and charge transfer can vary significantly with the charge and electron configuration of the metal participating in binding.

Equilibria and Rate Phenomena from Atomistic to Mesoscale: Simulation Studies of Magnetite.

Batteries are dynamic devices composed of multiple components that operate far from equilibrium and may operate under extreme stress and varying loads. Studies of isolated battery components are valuable to the fundamental understanding of the physical processes occurring within each constituent element. When the components are integrated into a full device and operated under realistic conditions, it can be difficult to decouple the physical processes that occur across multiple interfaces and multiple length scales.

Investigating the Complex Chemistry of Functional Energy Storage Systems: The Need for an Integrative, Multiscale (Molecular to Mesoscale) Perspective.

Electric energy storage systems such as batteries can significantly impact society in a variety of ways, including facilitating the widespread deployment of portable electronic devices, enabling the use of renewable energy generation for local off grid situations and providing the basis of highly efficient power grids integrated with energy production, large stationary batteries, and the excess capacity from electric vehicles. A critical challenge for electric energy storage is understanding the basic science associated with the gap between the usable output of energy storage systems and their theoretical energy contents. The goal of overcoming this inefficiency is to achieve more useful work (w) and minimize the generation of waste heat (q).