Ru Nanoparticles on K Doped γ-Alumina with Abundant Surface Superbasic Sites for Ammonia Decomposition

Catalytic performances of Ru nanoparticles (NPs) on the oxides can be remarkably regulated by the surface properties of oxide supports. Herein, we show that activity of Ru NPs on γ-Al 2 O 3 can be enhanced via generation of superbasic sites on the γ-Al 2 O 3 support by K doping (K‒Al 2 O 3 ). The optimized Ru/K‒Al 2 O 3 catalyst achieves a hydrogen production rate of 25.2 mmol g cat −1 min −1 at 450 °C. The Ru/K‒Al 2 O 3 catalyst also gives highly stable performance for over 120 h. Characterization results show that the presence of superbasic sites induce much enhanced interaction between Ru NPs and K‒Al 2 O 3 support. Moreover, the surface superbasic sites play a key role in modulating electronic property of Ru NPs, which can promote electron donation from support to Ru NPs and greatly enhance the intrinsic activity of the Ru NPs. The use of K‒Al 2 O 3 superbase for Ru-based ammonia decomposition catalysts are expected to expand the application of solid superbase materials. Graphical Abstract