Aerosol-assisted synthesis of hybrid/composite porous nanostructures for CO₂ utilization

The urgent global demand for sustainable carbon management has intensified research into advanced materials and catalytic processes for CO₂ conversion. This feature article focuses on the intersection of aerosol-assisted synthesis (AAS) routes and the development of functional hybrid/composite porous nanostructures tailored for thermocatalytic CO₂ conversions. AAS provides a unique, versatile, and scalable platform for fabricating hybrid/composite nanostructures with tunable porosity, tailored compositions, and hierarchical architectures-attributes that are critical for enhancing catalytic performance, thermal stability, and resistance to deactivation. The review article provides an overview of the fundamental principles underlying AAS, including: aerosol generation as the starting point, precursor transformation from droplet/vapor to nanoparticle, particle manipulation for in-flight structure control, and nanostructure formation with engineered porosity. It further discusses both common and advanced AAS techniques developed for catalytic hybrid/composite nanostructures, such as aerosol spray pyrolysis, spray drying with a three-fluid nozzle strategy, flame-based aerosol processes (including double flame spray pyrolysis and its asymmetrical variant), and hybrid approaches integrating sol-gel chemistry, surfactant-assisted templating, and microfluidic processing. The applications of AAS-derived functional porous nanostructures are explored across a range of thermocatalytic CO₂ conversion processes, including CO₂ hydrogenation (methanol synthesis, methanation, and reverse water-gas shift), dry reforming of methane, bi-reforming of methane, carbonation reactions (e.g., dimethyl carbonate synthesis), and other emerging pathways. The review article concludes with a critical perspective on current challenges and future research directions, highlighting the importance of AAS-enabled control over structure-function relationships to optimize catalytic activity and selectivity for sustainable CO₂ utilization.