UC Riverside

Heterogeneous catalysis involves a complex interplay of adsorption, charge transfer, and catalyst restructuring at solid–gas or solid–liquid interfaces. While first-principles methods such as KS-DFT and AIMD accurately describe chemisorbed species, they struggle to capture weakly bound or dynamic molecules subject to thermal fluctuations. Continuum models provide macroscopic insight into electrostatics and transport but often neglect the interfacial molecular structure, especially within the Stern layer. The challenge is even greater at gas–solid interfaces, where the gas phase is typically ignored, giving rise to a long-standing pressure gap between theory and experiment. This Perspective advocates a statistical-mechanical description of interfacial species using classical density functional theory (cDFT), in which physisorption and gas/liquid-phase inhomogeneity near catalytic surfaces are represented by molecular density distributions rather than fixed atomic configurations. More importantly, we emphasize the necessity of integrating KS-DFT with such microenvironmental models and propose several potential strategies for coupling electronic-structure calculations with continuum and statistical-mechanical approaches. By merging first-principles, continuum, and statistical-mechanical approaches within open-system, physics-informed frameworks, it becomes possible to bridge electrochemical and thermocatalytic regimesfrom localized chemisorption to diffuse physisorptionand reveal the true complexity of catalytic interfaces.