Interfacial Metal-Support Interaction and Catalytic Performance of Perovskite LaCrO₃-Supported Ru Catalyst

Interfacial metal-support interaction (MSI) significantly affects the dispersion of active metals on the surface of the catalyst support and impacts catalyst performance. Understanding MSI is crucial for developing highly active and stable catalysts with a low metal loading, particularly for noble metal catalysts. In this work, we synthesized LaRuCr_1-O₃ catalysts with low Ru loading (x = 0.005, 0.01, and 0.02) using the sol-gel self-combustion method. We found that all of the Ru atoms immediately above or below the metal-support interface are closely bonded to the perovskite LaCrO₃ surface lattice through Ru-O bonds, enhancing the MSI via interfacial reaction and charge transfer mechanisms. We identified a variety of Ru species, including small 3D Ru nanoparticles, 2D dispersed Ru surface atoms, and even 0D Ru single atoms. These highly dispersed Ru species exhibit high activity and stability under dry reforming of methane (DRM) conditions. The LaRu_0.01Cr_0.99O₃ catalyst with very low Ru loading (0.42 wt %) was stable over a 50 h DRM test and the carbon deposition was negligible. The CH₄ and CO₂ conversions at 750 °C reached 83 and 86%, respectively, approaching the theoretical thermodynamic equilibrium values.