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

Abstract

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.