Lewis Pair-Engineered CuMnO<sub>x</sub> as Cold-Adapted Multinanozyme for Cooperative Hydrolytic and Oxidative Degradation of Raw Corn Stalk.

Abstract

The full-component utilization of lignocellulosic biomass under mild conditions remains a formidable challenge for both biocatalytic systems and industrial processes. Herein, we report a Lewis pair engineering strategy to construct a defective Cu-doped Mn oxide nanozyme (D-CuMnO_x) featuring the simultaneous introduction of manganese and oxygen vacancies. The resulting undercoordinated Mn sites act as Lewis acids to activate glycosidic bonds, while adjacent oxygen species serve as Lewis bases to promote nucleophilic attack and electron transfer, thereby collectively lowering the energy barriers for both hydrolytic and oxidative reactions. As a consequence, D-CuMnO_x exhibits an approximately fourfold enhancement in glycosidase activity and markedly improved cold-adapted performance compared with oxygen-vacancy-only CuMnO_x, while simultaneously maintaining robust oxidase-like activity. Benefiting from these advantages, D-CuMnO_x serves as a cooperative hydrolytic-oxidative platform that enables the depolymerization of cellulose and hemicellulose alongside the oxidative cleavage of lignin, thereby achieving simultaneous degradation of the major components in raw corn stalks under mild and low-temperature conditions. This work establishes Lewis pair engineering as a versatile strategy for the rational design of multifunctional cold-adapted nanozymes and highlights their considerable potential for sustainable biomass valorization.