A More Accurate Kinetic Monte Carlo Approach to a Monodimensional Surface Reaction: The Interaction of Oxygen with the RuO2(110) Surface

Characterization of adsorption sites on IrO2via temperature programmed O2 desorption simulations

This study presents simulations of temperature-programmed desorption (TPD) profiles using desorption energy data from density functional theory (DFT) calculations. We apply this method to investigate the desorption of oxygen (O2) from IrO2(110) to gain insight into the kinetics of oxygen coupling and desorption, important elementary steps in the oxygen evolution reaction (OER). Initially, we confirm the thermodynamically stable adsorption site for oxygen in the pristine IrO2(110) as IrCUS, even with a high oxygen coverage. We successfully simulate TPD for O2 desorption, achieving good agreement with experimental TPD data for different initial oxygen exposures when including more than one adsorption site. We identify a new adsorption site, related to the formation of steps on IrO2(110)(IrCUS-step-0.5), that is essential for reproducing the experimental TPD. Our findings suggest that the observed TPD peaks are the result of different adsorption sites on the surface, rather than solely a lateral interactions effect. This work provides insight into the behavior of oxygen adsorption on IrO2, with implications for understanding surface reactivity and catalytic processes involving this material.

Kinetic Monte Carlo simulations of the dry reforming of methane catalyzed by the Ru (0001) surface based on density functional theory calculations

This study shows the main pathways for the DRM reaction and the competitive RWGS reaction upon changing reaction conditions, displaying the importance of including lateral–lateral interactions to describe the reaction in agreement with the experiment.

Close band center and rapid adsorption kinetics facilitate selective electrochemical sensing of heavy metal ions

Combining density functional theory calculation with experiments and kinetics simulation, a multiscale framework describing the influence of reactant-substrate interaction on electrochemical performance was proposed. It was found that the close band center and the rapid adsorption kinetics facilitated the highly selective response of Ni(111) toward Cu(ii), providing a useful tactic to investigate the mechanism of electro-selectivity. This work not only verified that the interaction strength in the ex situ conditions, and kinetics rate could be applied to evaluate the electrochemical selectivity, but also contributed to the options and forecasting of selective electrode materials for heavy metal ions.

Two-dimensional nitrides as highly efficient potential candidates for CO2 capture and activation

The performance of novel two-dimensional nitrides in carbon capture and storage (CCS) is analyzed for a broad range of pressures and temperatures. Employing an integrated theoretical framework where CO2 adsorption/desorption rates on the M2N (M = Ti, Zr, Hf, V, Nb, Ta, Cr, Mo, and W) surfaces are derived from transition state theory and density functional theory based calculations, the present theoretical simulations consistently predict that, depending on the particular composition, CO2 can be strongly adsorbed and even activated at temperatures above 1000 K. For practical purposes, Ti2N, Zr2N, Hf2N, V2N, Nb2N, and Ta2N are predicted as the best suited materials for CO2 activation. Moreover, the estimated CO2 uptake of 2.32-7.96 mol CO2 kg-1 reinforces the potential of these materials for CO2 abatement.

Global optimization and oxygen dissociation on polyicosahedral Ag32Cu6 core-shell cluster for alkaline fuel cells

The structure of 38 atoms Ag-Cu cluster is studied by using a combination of a genetic algorithm global optimization technique and density functional theory (DFT) calculations. It is demonstrated that the truncated octahedral (TO) Ag32Cu6 core-shell cluster is less stable than the polyicosahedral (pIh) Ag32Cu6 core-shell cluster from the atomistic models and the DFT calculation shows an agreeable result, so the newfound pIh Ag32Cu6 core-shell cluster is further investigated for potential application for O2 dissociation in oxygen reduction reaction (ORR). The activation energy barrier for the O2 dissociation on pIh Ag32Cu6 core-shell cluster is 0.715 eV, where the d-band center is -3.395 eV and the density of states at the Fermi energy level is maximal for the favorable absorption site, indicating that the catalytic activity is attributed to a maximal charge transfer between an oxygen molecule and the pIh Ag32Cu6 core-shell cluster. This work revises the earlier idea that Ag32Cu6 core-shell nanoparticles are not suitable as ORR catalysts and confirms that Ag-Cu nanoalloy is a potential candidate to substitute noble Pt-based catalyst in alkaline fuel cells.