From Materials to Interfaces: Design of MAX-Phase and MXene Coatings for Predictive Corrosion Mitigation in Concentrated Solar Power Systems

Abstract The performance of concentrated solar power (CSP) plants is greatly limited by corrosion and degradation at the interfaces between materials and their environments, particularly under high-temperature molten salt conditions. While advanced alloys and conventional coatings are considered good alternatives to increase their service life, the reliability of future generations of this technology remains uncertain. In this regard, MAX phases and MXenes should not be considered as inherently superior replacements but rather as tunable systems that offer alternative approaches to interface design, oxidation control, and degradation mitigation. In this perspective, we envision reinterpreting MAX phases as a chemically expandable and defect-sensitive platform, in which integrating compositional variations, structural hierarchies, and transformation pathways into MXenes will enable the development of a promising corrosion mitigation strategy. Therefore, we propose that MXenes should be considered as dynamically evolving surfaces, with their termination chemistry, defect topology, and interactions with the environment playing critical roles in their long-term performance. To address the current challenges, we recommend an integrated multiscale approach that combines advanced in situ characterization techniques, atomistic simulations, thermodynamic modeling, and machine learning. This approach will help to establish predictive relationships among structure, defects, and performance, leading to more durable, multifunctional interfaces.