Efficient low‐temperature NH 3 decomposition to H 2 over strain‐engineered Ru/ Y 2 O 3 ‐ MgO : Kinetic and mechanistic insights

Abstract Ammonia decomposition is a promising route for on‐demand hydrogen production. Herein, we report the synthesis of a compressive‐strained Ru/Y 2 O 3 ‐MgO catalyst that exhibits exceptional low‐temperature activity for ammonia decomposition. Comprehensive characterizations reveal an ultrathin nanosheet morphology with strong metal‐support interactions, which induce lattice mismatch and generate a compressive strain of approximately 4.9%. Kinetic modeling and density functional theory calculations both identify recombination desorption of N 2 as the rate‐determining step. The compressive strain modulates the electronic structure by shifting its center downward, thereby reducing the activation energy for NN bond recombination and enhancing catalytic performance. Remarkably, the optimized catalyst with ultralow Ru loading (0.91 wt%) achieves an unprecedented hydrogen production rate of 2479.9 mmol·g Ru −1 ·min −1 at 450°C, the highest reported value under comparable conditions. This work provides both kinetic and mechanistic insights into the role of strain engineering in promoting ammonia decomposition, offering a promising avenue for efficient hydrogen production.