Multi-cationic oxides containing five or more elements have recently attracted significant attention as the field of high-entropy materials (HEMs) expands beyond its original focus on high-entropy alloys (HEAs) to encompass oxide systems. High-entropy oxides (HEOs) offer a unique combination of compositional complexity, tunable electronic structures, and enhanced thermal and chemical stability, making them promising materials for a wide range of energy and environmental applications. Despite their considerable potential, HEOs have seen only limited exploration in heterogeneous catalysis and adsorption technologies. A major bottleneck is the absence of robust and scalable synthesis methods that can reliably produce porous, high-surface-area HEOs tailored for these applications. 

Through support from the Swiss National Science Foundation (SNF) Ambizione program, this project addresses these challenges by developing versatile synthesis strategies for porous high-entropy oxides. Particular emphasis are on approaches that can produce HEOs with the high surface areas and accessible active sites required for catalytic and adsorption applications.

Given the vast compositional and synthetic parameter space associated with HEOs, conventional trial-and-error optimization approaches are inefficient. Therefore, the project utilizes high-throughput synthesis and characterization capabilities available in Switzerland, like SwissCAT+, to accelerate materials discovery and optimization.

Building upon these synthetic advances, the project investigates how high-entropy oxides can be tailored for two key application areas. First, we explore their use in heterogeneous catalysis, where their compositional complexity may generate unique active sites, enhance catalyst stability, and improve resistance to sintering and deactivation, specifically CO2 hydrogenation as a model reaction. Second, we will examine their potential as adsorbent materials separation processes, where tunable surface chemistry and defect structures may enable improved adsorption capacity and selectivity. Here, in situ characterization techniques such as XRD and XAS are utilized to understand how these materials uniquely behave under operating conditions.

Through these studies, the project seeks to establish fundamental design principles for high-entropy oxides and expand their application in sustainable catalytic and separation technologies.

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