Synergizing Mg Single Atoms and Ru Nanoclusters for Boosting the Ammonia Borane Hydrolysis to Produce Hydrogen

Development of efficient catalysts with high H₂O molecule activation ability holds great importance for H₂ production. Herein, enzyme-mimic Mg single atoms catalysts (SACs) coordinated by B/N-doped carbon nanotube (BNC), was constructed as a high-performance support for ruthenium (Ru) nano-clusters. Dual functions of Mg SACs were discovered, where the Mg atoms beneath Ru catalysts built an interfacial electron polarization, inducing electron transfer from Ru to the Mg-BNC support. In addition, the oxyphilic Mg SACs adjacent to the Ru catalysts could actively participate in H₂O adsorption. The combination of experimental characterization, reaction kinetics study and density functional theory (DFT) calculations validated a stronger intrinsic H₂O activation capability at the positive Ru sites. Meanwhile, the synergistic Mg SACs jointly contribute to the acceleration of the sluggish H₂O dissociation process in ammonia borane (AB) hydrolysis reaction, resulting in exceptional hydrogen production activity and catalytic stability, outperforming most state-of-the-art Ru-based catalysts. This work provides a new strategy for utilizing alkaline earth metals as both the electronic promoter and the reactant activator, offering inspiration for the development of advanced heterogeneous catalysts.