Continuous N2O Capture and Reduction to N2 Using Ca-Zeolite Adsorbent and Pd/La/Al2O3 Reduction Catalyst

Abstract

There is an urgent need to develop effective methods for converting nitrous oxide (N₂O) into nonharmful N₂ because N₂O is a potent greenhouse gas, and its increasing concentration in the atmosphere is a major concern for global warming. In this study, we developed a two-step N₂O capture and reduction system, employing CaO-incorporated zeolites (Ca-zeolites) as N₂O adsorbents and Pd nanoparticles on La-containing Al₂O₃ (Pd/La/Al₂O₃) as catalysts for N₂O reduction. This process is suitable for continuous operation over a temperature swing of 50–150 °C. The N₂O capture capacity and subsequent reduction ability were preserved for at least 15 h (10 cycles). Notably, this system can operate at low temperatures (below 150 °C) using a simple temperature-swing process in the presence of O₂.