Gadolinium-Mediated Oxygen Affinity Induced Efficient Covalorization of CH4 and N2O in an Ir-Gd2O3 Single-Atom Catalyst.

Abstract

Valorization of nitrous oxide (N₂O) and methane (CH₄) for chemicals has garnered growing interest for mitigating their climate impact. Dry reforming of methane (DRM) with industrial N₂O exhaust offers a promising route. However, the DRM reaction often requires rigorous temperatures (>650 °C) accompanied by overoxidation, hindering CO and H₂ formation due to weak oxygen binding on catalysts. Here, we report a Gd₂O₃-supported iridium single-atom catalyst (SAC), with an effective Ir₁-Gd₂O₃ synergy. At only 450 °C, it exhibits high N₂O (99.3%) and CH₄ (48.2%) conversion and syngas yields (138.3 mol of CO kg_cat^-1 h^-1 and 184.9 mol of H₂ kg_cat^-1 h^-1) and a H₂/CO ratio of 1.34, over 100 h. Mechanism studies revealed that Gd₂O₃ enabled controlled oxygen release for CO production, while Ir single atoms facilitated CH₄ activation and H₂ formation. This work presents a low-temperature, sustainable strategy for greenhouse gas utilization and highlights the potential of Gd₂O₃-based single-atom catalysts in heterogeneous catalysis.