The art of custom-intercalating 42 metals into layered titanate nanostructures

Researchers report a synthesis method enabling direct intercalation of many metal cations into layered titanates, enabling tailored catalysts and energy storage materials.

(Nanowerk News) A research team, affiliated with UNIST has reported a novel synthesis strategy that enables the direct intercalation of a wide range of metal cations into the interlayer spaces of layered titanate (LT) structures (Advanced Materials, “Diverse Cation Exchange in Layered Titanate Nanostructures for Tailored Catalysis”). This approach opens new possibilities for designing highly tailored catalysts and energy storage materials for specific industrial applications. Professors Seungho Cho (Department of Materials Science and Engineering), Kwangjin An (School of Energy and Chemical Engineering), and Hu Young Jeong (Graduate School of Semiconductor Materials and Devices Engineering) at UNIST, in collaboration with Professor Jeong Woo Han from Seoul National University, announced this advancement. Their method allows for the one-step synthesis of a flexible, H+-intercalated LT (called H-LT), which can undergo direct ion-exchange to incorporate a wide range of metal cations—from alkali metals (AMs) to lanthanides—without compromising structural integrity. Preparation and characterization of LT and the M-LTs. (Image: UNIST) (click on image to enlarge) LTs are titanium oxide-based materials composed of thin, stacked layers. Their ability to host various metal ions has made them attractive as catalyst supports and electrode materials. However, traditional metal incorporation methods often involve high-temperature processing and harsh chemicals, limiting the types of metals that can be used and complicating large-scale production. To address these challenges, the team developed a bottom-up approach using ammonium hydroxide. Precursor materials naturally organize into proton-rich LTs, which can then exchange protons for desired metal ions when immersed in solution. This technique can intercalate up to 42 different metals across five groups—including AMs and rare earth elements—and can even incorporate over 30 different metals simultaneously in a single structure. The team demonstrated the practical potential by creating a rhodium(Rh)-supported catalyst. When tested for hydroformylation of propylene—a key step in plastics and detergent production—the catalyst supported on potassium-intercalated LT showed more than three times the activity of conventional Rh catalysts. Analyses and computational modeling suggested that the intercalated AMs facilitate charge transfer to Rh, improving adsorption and catalytic efficiency. This work provides more than synthesizing new materials. Rather it offers a comprehensive platform—an intercalation library—that can be tailored for various catalytic and energy applications. “Our work goes beyond just synthesizing a new material,” said Professor Cho. “It is about establishing a flexible, scalable technology for selecting and combining metals, opening up new avenues for cost-effective catalysts and high-performance energy storage.”