Phase Tailoring in Ruthenium‐Based Nanomaterials: Strategies, Structures, and Catalytic Applications

Ru-based nanomaterials are highly promising catalysts for energy storage and conversion due to their high intrinsic activity and cost-effectiveness among platinum-group metals. Phase tailoring, which directly controls the atomic arrangement, has emerged as a powerful strategy for precisely tailoring their physicochemical properties. This review provides a comprehensive overview of recent advances in phase tailoring of Ru-based nanomaterials. It starts with cataloging the newly developed phases of Ru-based nanomaterials from unconventional crystalline and amorphous structures to intermetallic and chalcogenide compounds, and discusses their synthetic principles from the thermodynamic and kinetic perspectives. We then summarize the representative synthetic methodologies that enable these novel phases and highlight the resulting Ru-based nanomaterials with novel phases. Furthermore, we review their electrocatalytic applications in water splitting and fuel cells, with the establishment of structure-performance relationships. Finally, the review concludes by pointing out the potential challenges and presenting a perspective on future research, aiming to guide the rational design of next-generation Ru-based catalysts.