Piezocatalysis for Small-molecule Conversion: From Mechanistic Fundamentals to Emerging Applications

Piezocatalysis harnesses the electromechanical coupling of non-centrosymmetric materials to convert mechanical energy into dynamic interfacial polarization and redox driving forces, thus offering a distinctive route for small-molecule activation under mild conditions. This review first examines the fundamental mechanisms underlying piezocatalytic charge generation, charge separation, charge transport, and interfacial reaction The rapidly expanding family of piezocatalytic materials—including perovskite and related oxides, layered bismuth-based compounds, ferroelectric polymers, wurtzite-type semiconductors, two-dimensional van der Waals materials, and other inorganic piezoresponsive materials—is then discussed along with framework, molecular, and organic–inorganic hybrid systems. Strategies for tuning the piezocatalytic activity are further organized within a four-dimensional regulation framework encompassing lattice polarization and microstructure, interfacial, and surface properties, highlighting the relationships among the material structure, electromechanical response, and catalytic performance. The emerging application landscape, spanning water splitting, CO₂ reduction, N₂ fixation, nitrate reduction, O₂ reduction for H₂O₂ production, reactive oxygen species -mediated degradation of small organic pollutants, and oxidative conversion of methane is discussed. Particular attention is focused on the mechanistic complexity of piezocatalytic reactions and the challenges associated with comparing the piezocatalytic performance across different materials and operating conditions. Finally, the key barriers to practical deployment, including mechanistic decoupling, performance standardization, stability, and reactor engineering, are discussed. By connecting fundamental electromechanical phenomena with materials design and small-molecule reactivity, this review outlines the opportunities and principles for advancing piezocatalysis from proof-of-concept demonstrations toward robust and scalable chemical conversion technologies.