Electron-Pump Engineering via CuO-Sm2CuO4 Heterojunction for Side-on N2O Activation and Efficient Catalytic Decomposition under O2-Rich Conditions

Catalytic N2O decomposition on CuO-based catalysts is limited by poor N-O activation. Interfacial electron engineering can modulate active-site structure, yet its effect on N2O remains unclear. Here, we have developed a CuO-Sm2CuO4 heterostructure, which achieves over 90% N2O decomposition at 400 °C in 5% O2. In simulated NOx-N2O co-reduction, it retains 96% activity at 450 °C for 168 hours. This performance indicates significant application potential compared to reported catalyst systems. Our study demonstrates that Cu2+-O- sites on as-synthesized CuO-based catalysts drive N2O decomposition via the Mars-van-Krevelen mechanism, generating Cu+ species that complete the catalytic cycle through the Langmuir-Hinshelwood pathway. On pure CuO, Cu+ adsorbs N2O end-on and activates it via σ-backdonation. In contrast, the CuO-Sm2CuO4 heterojunction forms a dynamic electron-pumping interface where Sm2CuO4 donates electrons to stabilize Cu+, reverses N2O’s adsorption-configuration to side-on and enables π-backdonation-mediated activation. This work advances understanding of interfacial electron regulation in heterogeneous catalysis and provides a strategy for designing high-performance N2O decomposition catalysts.