Investigation on the dual functionality of high-entropy oxides for combined carbon capture andconversion

Combined capture and conversion of CO₂ (CCCC) presents a promising approach to simultaneously reduce emissions from industrial sources and produce value-added products such as methane, which can be reintegrated into industrial energy systems. Achieving CCCC requires dual-functional materials (DFM) capable of both capturing CO₂ and catalytically converting it to a target product in a cyclic process. We have recently developed such materials using high-entropy oxides (HEOs) derived from high-entropy hydroxycarbonates that exhibit remarkable tailorability and stability compared to other DFM materials. "High entropy" refers to the incorporation of five or more cations into a single crystal structure, resulting in enhanced tunability of both CO₂ adsorption capacity and catalytic performance. However, understanding how individual cations contribute to these properties requires comprehensive characterization. To address this, a combination of advanced analytical techniques are needed—including in-situ X-ray absorption spectroscopy (XAS), in-situ X-ray diffraction (XRD), and ((S)TEM-EDX). Our goal is to elucidate the role of high-entropy composition in governing the structure-property-performance relationships of these multifunctional materials, thereby advancing their potential for scalable CCCC technologies.