Biomass valorization using 3D-printed catalysts.

Catalytic biomass valorization into value-added chemicals is crucial to reduce reliance on fossil resources and mitigate environmental impacts. However, more than 90% of chemical manufacturing still relies on conventional catalysts, underscoring the need for sustainable alternatives. Three-dimensional (3D) printing offers unique opportunities to design catalysts with tailored geometries and pore architectures, enhancing mass transfer, active site accessibility, and reusability. Most reviews of 3D-printed catalysts focus on small molecule reactions such as ammonia decomposition or methanol dehydration. In contrast, this review was conceived to provide a comprehensive overview on the design and application of 3D-printed catalysts in biomass conversion. Recent advances in metal-based, acid/base-mediated, enzymatic and photocatalytic systems are discussed, while assessing the benefits and drawbacks of 3D printing compared to traditional catalyst fabrication. By addressing current challenges and outlining future directions, this review highlights the capacity of 3D-printed catalysts to bridge laboratory innovation and industrial application, paving the way for scalable, cost-effective, and sustainable green chemical manufacturing in the emerging circular bioeconomy.