Electric field-assisted NSR process for lean NO reduction at low temperatures

Lean-burn engines are gaining attention for their lower CO₂ emissions, higher thermal efficiency, and improved fuel economy compared to traditional combustion engines. However, they present some difficulty for reducing nitrogen oxides (NO) because of residual oxygen. To address this difficulty, NO storage reduction (NSR) system, which combines noble metals and NO adsorbents, is developed as a viable approach. But it requires cyclic operation, which adversely affects fuel efficiency. A novel approach proposed in this work is electric field-assisted lean NO reduction, which applies an electric field to the NSR catalyst during lean conditions. This innovation uses surplus vehicle electricity for exhaust purification, enhances hydrogen transfer, and improves NO reduction, even at low temperatures. Tests with a 3 wt% Pt-16 wt% BaO/CeO₂ catalyst demonstrate markedly higher NO conversion to N₂ (13.1% vs. 2.9% without an electric field). This process is effective with extended electric field exposure, doubling the conversion rate. Electric field-assisted lean NO reduction, by improving NSR technology, can enhance NO conversion efficiency, reduce emissions, and optimize fuel efficiency in lean-burn engines.