A new electrification strategy devised by researchers in China strengthens nitrogen oxides (NO_x) emission control at low temperatures in diesel-powered vehicles.

While NO_x storage reduction enhances emission control in these vehicles, trends in engine design and an increase in idling in traffic cause exhaust temperatures to fall below 250° C, which is too low to support catalytic NO_x conversion. The electrified NO_x storage reduction approach described in Environmental Science & Technology was developed to address this issue.

The scheme applies low input power electricity in the 0.5 W to 4 W range to platinum and potassium co-supported antimony-doped tin oxides. These conductive catalysts trigger NO_x storage reduction reactions in the presence of’ propylene, which serves as a reductant.

The researchers from University of Jinan, Chinese Academy of Sciences and Ningbo University demonstrated that the ignition temperature for 10% NO_x conversion was reduced by nearly 100° C to 165° C. A reduction in fuel-lean power implemented to optimize the power configuration increased the maximum energy efficiency by 23%.

As the electric power input can be controlled in real time to tackle pollutant emissions, wide deployment of the electrification process is expected to further reduce exhaust emissions in diesel as well as hybrid vehicles.