Two-Dimensional Confinement Effects on the Dynamical Aspects of CO Oxidation over Pt(111)

Abstract

This study investigates the effects of two-dimensional (2D) confinement on CO oxidation reaction over Pt(111) surfaces, emphasizing the structural, electronic, and dynamical aspects of CO₂ formation and desorption. Using pristine and single-defect hexagonal boron nitride (h-BN) and graphitic carbon nitride (g-C₃N₄) as overlayers, we found that confinement by nitrogen-vacancy h-BN (NV) induces a significant reduction, greater than that of graphene (Gr), in the activation energy barrier for CO₂ formation. The confinement effect on adsorption depends on the reference states chosen for adsorption energy calculations. Reference states, such as stable or original intersurface gaps, can yield either positive or negative confinement energy values, indicating adsorption weakening or strengthening, respectively. Importantly, adsorption weakening correlates better with barrier reduction. Post-transition-state dynamical simulations of CO₂ desorption revealed pronounced vibrational oscillations. NV and Gr confinement led to complex vibrational features, indicating stronger interactions between CO₂ and the 2D cover. This study highlights the profound impact of 2D confinement on catalytic processes, providing insights into how 2D materials modulate the electronic structure and vibrational dynamics of reactions. The findings could guide the design of efficient catalysts for industrial applications, particularly in heterogeneous catalysis.