Human-induced carbon dioxide overproduction, chiefly generated through the burning of fossil fuels and manufacturing activities, directly leads to the greenhouse effect. These environmental changes trigger consequences including oceanic elevation, amplified climatic disturbances, and permanent ecological destabilization. Carbon conversion technologies that chemically alter CO₂ into stable derivatives emerge as critical solutions for addressing these climate challenges. Drawing inspiration from natural photosynthesis, enzyme-photo-coupled catalytic systems harness light energy to drive electrons excitation and further activate enzymatic reactions, which offering a sustainable approach for converting CO₂ into valuable products. This integrated strategy merges the substrate specificity of enzymes with solar energy input, addressing critical demands in bio-manufacturing and renewable energy development. Nonetheless, microscale incompatibility between photocatalytic and enzymatic reaction conditions limit system efficiency, while macroscale light attenuation due to photosensitizer absorption impedes scalability. Furthermore, sustained illumination-induced enzyme deactivation and suboptimal solar energy conversion pose challenges for industrial deployment. To address these multiscale challenges, we developed a gas-spray photocatalytic reactor enabling process intensification through spatial and temporal optimization. Macroscopically, enhanced light penetration and continuous-flow operation ensure stable catalytic performance. Microscopically, autonomous spatial segregation of enzymes and photosensitizers within gas-sprayed microdroplets resolves interfacial incompatibility, while proximity-driven reaction acceleration enhances overall kinetics. Leveraging the reactor's optical efficiency, we pioneered a gas-spray cofactor regeneration platform enabling continuous photon-driven redox cycling. This advancement facilitated a robust methodology for enzymatic formic acid synthesis with improved continuity. Mechanistic investigations revealed that microdroplet confinement extends enzyme stability by isolating biocatalysts from photogenerated radicals. Computational modeling confirmed that localized concentration gradients and reduced diffusion distances synergistically boost reaction dynamics, elucidating previously unexplained microdroplet acceleration mechanisms. Based on the higher light illumination efficiency in the gas-spray photocatalytic reactor, we first established the gas-spray photocatalytic cofactor regeneration system and proposed a new method for efficient and continuous photocatalytic regeneration of cofactors. Further, an efficient and continuous enzyme-photo-coupled synthesis strategy of formic acid was established utilizing the process intensification properties in gas-spray photocatalytic reactor. Subsequently, we further explored the microscale process intensification mechanism of the enzyme-photo-coupled catalytic system in the gas-spray photocatalytic reactor, and the spontaneous control of enzyme and photosensitizer compartmentalization in the gas-sprayed microdroplets were elucidated, explaining the mechanism of prolonged enzyme activity retention time. Higher solar energy utilization and light intensity of microdroplets, and a highly regionalized distribution of substances, are proved to be the origin of better catalytic performance. Moreover, we proposed numerical calculation for enhanced overall reaction rate based on regionalization and proximity effects, thus addressing the challenge of multi-scale process intensification of enzyme-photo-coupled catalysis and providing a new theoretical basis for the unclear mechanism of reaction rate enhancement in microdroplets. Through integration of the gas-spray enhanced CO2 capture process intensification properties with enzyme-photo-coupled catalysis system, we engineered a scalable platform for continuous CO2 fixation. This architecture demonstrates broad applicability in solar-driven biocatalytic processes, establishing foundational principles for industrial implementation.
