Boosting Hydrogen Evolution from Ammonia–Borane Hydrolysis Catalyzed by Poly(N‐Vinyl‐2‐Pyrrolidone)‐Stabilized Ruthenium‐Based Nanoclusters Catalysts

Abstract The exploitation of economical and high‐efficient heterogeneous catalysts plays a vital role in ammonia‐borane (NH₃BH₃, AB) hydrolysis for hydrogen evolution. Herein, poly(N‐vinyl‐2‐pyrrolidone) (PVP) stabilized highly dispersed Ru–Ni nanoclusters immobilized on reduced graphene oxide (rGO) are successfully synthesized via in situ chemical reduction. The optimized Ru₁Ni₁@PVP/rGO‐1 catalyst exhibits a superior catalytic performance toward hydrolytic dehydrogenation of AB for hydrogen evolution, with a low activation energy (E_a) of 21.1 kJ mol⁻¹ and a high turnover frequency (TOF) value of 425.1 mol_H2 mol_Ru⁻¹ min⁻¹at 298 K. Moreover, an outstanding recyclability with 82.1% of the initial catalytic activity is achieved after 20 consecutive cycles due to PVP coating that can effectively prevent the agglomeration of nanoclusters during the recycling tests. Experimental analyses and DFT calculations reveal a synergistic effect in Ru–Ni nanoclusters, resulting in a strong adsorption of AB molecules and an easy activation of water molecules on Ru–Ni nanoclusters. These findings in this study open a new avenue for a hopeful design of highly efficient heterogeneous catalysts.