Adaptive Catalytic Interfaces for Biomass-Derived Model Compounds: Dynamic Active Sites, Microenvironments, and Operando-Guided Design.

Rational catalyst design for biomass valorization often relies on static descriptors, although water, hydrogen, electric potential, concentrated oxygenates, and reactive intermediates can reorganize catalytic interfaces during turnover. This review develops an adaptive-interface framework in which the relevant entity is the distribution of working states established under reaction conditions. Four coupled phenomena are integrated: reaction-induced restructuring; solvent-, confinement-, and wettability-controlled microenvironments; cooperative chemistry involving spillover, bifunctionality, and site proximity; and operando-to-model workflows. Studies of 5-hydroxymethylfurfural, furfural, lignin-derived oxygenates, and reductive catalytic fractionation show how phase, valence, hydration, hydrogen speciation, and interfacial proton transfer can redirect elementary pathways without changing nominal catalyst composition. Representative examples include nickel oxyhydroxide phase transitions, solvent-modulated active hydrogen, water-mediated hydrogen heterolysis, and metal-support coupling of hydrogen activation with selective C-O or C=O conversion. A closed-loop workflow combining operando spectroscopy, transient/isotopic kinetics, explicit-solvent computation, microkinetics, and data-driven exploration is proposed to map working states and guide synthesis. This perspective shifts rational design from optimizing a precatalyst toward engineering the interface present during reaction. Mechanistic evidence centers on molecule-defined substrates and lignin-derived models; lignocellulosic fractionation is included as process context. Here, operando denotes catalyst-state characterization during turnover with concurrent measurement of catalytic function, not operando analysis of intact biomass.