Improved oxygen electrocatalysis is crucial for the ever-growing energy demand. Metal-nitrogen-carbon (M-N-C) materials are promising candidates for catalysts. Their activity is tunable via varying electronic and geometric properties, such as porosity. Because of the difficulty in modeling porosity, M-N-Cs with variable surface curvature remained largely unexplored. In this work, we developed a realistic in-pore dual-atom site M-N-C model and applied density functional theory to investigate the surface curvature effect on oxygen reduction and evolution reactions. We show that surface curving tailors both scaling relations and energy barriers. Thus, we predict that adjusting the surface curvature can improve the catalytic activity toward mono- and bifunctional oxygen electrocatalysis.

The catalytic reduction of CO₂/CO is key to reducing the carbon footprint and producing the chemical building blocks needed for society. In this work, we performed a theoretical investigation of the differences and similarities of the CO₂/CO catalytic reduction reactions in gas, aqueous solution, and aprotic solution. We demonstrate that the binding energy serves as a good descriptor for the gaseous and aqueous phases and allows catalysts to be categorized by reduction products. The CO^* vs O^* and CO^* vs H^* binding energies for these phases give a convenient mapping of catalysts regarding their main product for the CO₂/CO reduction reactions. However, for the aprotic phase, descriptors alone are insufficient for the mapping. We show that a microkinetic model (including the CO^* and H^* binding energies) allows spanning and interpreting the reaction space for the aprotic phase.

This work describes the behaviour of water molecules in 1-butyl-3-methylimidazolium tetrafluoroborate ionic liquid under nanoconfinement, between graphene sheets. By means of molecular dynamics simulations, the adsorption of water molecules at the graphene surface is studied. A depletion of water molecules in the vicinity of the neutral and negatively charged graphene surfaces, and their adsorption at the positively charged surface are observed in line with the preferential hydration of the ionic liquid anions. The findings are appropriately described using a two-level statistical model. The confinement effect on the structure and dynamics of the mixtures is thoroughly analyzed using the density and the potential of mean force profiles, as well as by the vibrational densities of the states of water molecules near the graphene surface. The orientation of water molecules and the water-induced structural transitions in the layer closest to the graphene surface are also discussed.