Abstract: Core-shell structured composite catalysts are characterized by the heterogeneous distribution of functional components, enabling precise regulation of the microenvironment for chemical reactions via spatial separation, thus exhibiting extensive applications in industrial catalysis. Endowed with structural customization advantages, 3D printing technology allows the precise construction of self-supporting catalysts with hierarchical channels. Among them, coaxial 3D printing realizes the spatial directional distribution of multi-materials in a single step via the simultaneous co-extrusion and controllable deposition of multi-channel inks. This technique exhibits great potential in the precise fabrication and efficient processing of core-shell structured composite catalysts. This review summarizes the research progress in the designable preparation and application of coaxial 3D-printed core-shell structure composite catalysts. The working principle of coaxial 3D printing, the structural design of coaxial nozzles, and the formulation of 3D printing inks are systematically elaborated. It also recapitulates the application advances of 3D-printed core-shell catalysts in vehicle exhaust treatment, the catalytic conversion of liquid organic pollutants, and the catalytic combustion of volatile organic compounds. The challenges confronting state-of-the-art technologies and important future research directions are thoroughly analyzed, thereby providing a valuable reference for the engineering application and high-performance development of novel core-shell composite catalysts.

Key words: core-shell structure, catalysts, coaxial 3D printing, additive manufacturing