Ru catalyst with the synergistic effect of single atom coupling nanoparticle and semi-embedded structure: breaking the activity and stability bottlenecks

Supported metal catalysts have important industrial applications such as energy storage/conversion, sustainable production of fuels and chemicals. However, the tendency of metal nanoparticles to grow into larger particles is an impediment for stable or excellent performance. Currently, there remains the formidable challenge of preparing supported metal catalysts that possess both high catalytic activity and stability. Herein, a novel supported Ru catalyst (Ru-Al₂O₃@CN-A) with a special structure where single Ru atoms and Ru nanoparticles embedded into N-doped carbon layer is successfully fabricated via a coating-impregnation-pyrolysis-etching (CIPE) strategy. Due to the synergy effect of H atoms generated at Ru single sites that migrate to the quinoline-bounded Ru nanoparticles to complete hydrogenation process, the Ru-Al₂O₃@CN-A catalyst gives a turnover frequency (TOF) of 4216 h⁻¹ for the selective hydrogenation of quinoline at 120 °C and 2 MPa H₂, which, to the best of our knowledge, is superior to most of reported noble metal-based catalysts. Furthermore, benefitting from the special structure that Ru species embedded into N-doped carbon layer, the Ru-Al₂O₃@CN-A catalyst demonstrates both high catalytic stability and thermal stability, and can be reused at least 10 cycles without activity loss, which is far more stable than commercial Ru/C catalyst with a traditional structure that Ru species dispersed on support surface. We anticipate that our approach paves the way towards the design of supported metal catalyst with both high catalytic activity and stability applied in energy storage/conversion, sustainable production of fuels and chemicals fields.