Polymeric emulsifier and diatom‐inspired membrane synergistically locate enzymes for interfacial cascade reactions

Abstract Conducting incompatible multi‐enzymatic and chemo‐enzymatic cascade reactions concurrently is highly attractive yet remains a persistent challenge. Herein, we demonstrated a diatom‐inspired microreactor, fabricated by armoring polymer‐stabilized water‐in‐oil emulsion with silica membranes for interfacial enzymatic catalysis in organic environments. Optimized interfacial engineering employing bis(trimethoxysilyl)hexane yielded resilient and porous silica membranes, facilitating efficient mass transfer. Crucially, synergistic polymer–enzyme–silica interactions promoted enzyme localization on the microreactors' interface, drastically reducing substrates' diffusion distance. Therefore, the polymer‐stabilized microreactors achieved a 45% higher product and retained 88% more activity after 10 cycles than the control in benzaldehyde lyase‐catalyzed benzoin condensation. Moreover, challenging chemo‐enzymatic cascades and multi‐enzymatic cascade reactions were demonstrated with high reactivity and recyclability in the diatom‐inspired microreactors, which compartmentalize distinct catalytic species to maintain their optimal catalytic conditions with minimum mass transfer resistance. The potential of this powerful platform to accommodate more challenging cascades for advanced synthetic applications is thus envisioned.