Rational Design of Earth-Abundant Catalysts for Efficient Energy and Environmental Systems

The transition toward a sustainable energy landscape relies heavily on the advancement of heterogeneous catalysis. While noble metals have traditionally dominated high-performance catalytic processes, their scarcity necessitates a paradigm shift toward earth-abundant alternatives. This presentation addresses the rational design of cost-effective, non-noble metal formulations, emphasizing the critical role of size and shape engineering in optimizing performance for diverse energy and environmental applications. Central to this discussion is the precise manipulation of local surface chemistry through advanced synthetic and modification strategies. We demonstrate that fine-tuning the nanoscale structure – specifically the particle size and crystal shape of metal oxides – serves as a powerful tool to modulate reactivity. Using CeO₂ as a model support and various transition metals as metal phases, we explore the impact of distinct nano-morphologies (nanorods, nanocubes, polyhedra) and metal particle size on key physicochemical properties. Detailed characterization reveals that the metal dispersion and the preferential exposure of specific crystal facets jointly dictate the density of oxygen vacancies and the extent of metal-support interactions. These structure-sensitivity relationships are exemplified through the development of transition metal composites that rival, and often surpass, noble metals in both oxidation and reduction reactions. Specifically, we demonstrate that copper-ceria catalysts with tailored support shape exhibit superior low-temperature activity for CO oxidation. Similarly, regarding reduction processes, Ni/CeO₂ nanorod composites with tailored Ni size demonstrate exceptional performance in CO₂ hydrogenation. In both instances, the specific nano-architecture induces synergistic interfacial effects, leading to robust stability and reactivity. Ultimately, this work provides a comprehensive rationale and design guidelines for fabricating highly active, non-noble metal catalysts capable of driving the critical chemical transformations required for a sustainable future.