Synergistic Structural and Electronic Modulation of Ceramic Fiber-Supported Ultralow‑Ru Catalysts for Exceptional Ammonia‑to‑Hydrogen Performance

Abstract

The development of efficient and durable catalysts for ammonia decomposition is critical to realizing a hydrogen economy, yet remains challenging due to the trade-off between noble metal loading and catalytic stability. Here, we demonstrate that ceramic fiber (CF) supports enable exceptional ammonia decomposition performance with ultralow Ru loading (0.3 wt%). The optimized Ru-CF catalyst achieves 99.47% NH₃ conversion at 525°C under a gas hourly space velocity of 9000 mL·g_cat⁻¹·h⁻¹, maintaining stable operation over 100 h—substantially outperforming its glass fiber (GF)-supported counterpart. A systematic mechanistic investigation reveals that the CF architecture not only induces abundant oxygen vacancies and modulates the electronic structure of Ru via strong metal–support interactions, but also optimizes Ru dispersion and creates a favorable distribution of acid–base sites. These synergistic effects collectively facilitate N─H bond cleavage and accelerate N₂ recombinative desorption—the kinetically relevant step—fundamentally enhancing the overall reaction kinetics. This work establishes fiber-based supports as a versatile platform for designing high-performance, low-loading precious metal catalysts, offering a viable pathway toward practical hydrogen production from ammonia.