Layered Ferrihydrite and BN Nanoparticle Heterostructures Doped with Ag for CO₂ Hydrogenation

Abstract

Iron-based catalysts are gaining increased attention as promising and cost-effective materials for CO 2 recycling. Their properties can be tuned by careful selection of the appropriate synthesis route, substrate, and catalytic system components. For the first time, a nanostructured material consisting of heterostructures of layered ferrihydrite (Fh) and hexagonal boron nitride (h-BN) nanoparticles has been obtained. Subsequent annealing ensures a uniform distribution of Fe nanoparticles (FeNPs) on the h-BN surfaces. Small Ag additions to the system lead to a significant decrease in the average size of FeNPs, presumably due to a seeding mechanism. Catalytic tests have shown that a low Ag content has a positive effect on the catalytic activity. Stability testing has demonstrated that the catalytic properties of the Fh/BN system improve over time, as does selectivity toward high-valueadded hydrocarbons. Computational methods suggest a surface atomic configuration in which one Ag atom substitutes for one Fe atom in the (110) plane, resulting in better CO 2 adsorption.