Promoted decomposition of NOx in automotive diesel-like exhausts by electro-catalytic honeycombs

Environ Sci Technol. 2015 Mar 17;49(6):3711-7. doi: 10.1021/acs.est.5b00226. Epub 2015 Mar 4.

Abstract

NO and NO2 (collectively called NOx) are major air pollutants in automotive emissions. More effective and easier treatments of NOx than those achieved by the present methods can offer better protection of human health and higher fuel efficiency that can reduce greenhouse gas emissions. However, currently commercialized technologies for automotive NOx emission control cannot effectively treat diesel-like exhausts with high NOx concentrations. Thus, exhaust gas recirculation (EGR) has been used extensively, which reduces fuel efficiency and increases particulate emission considerably. Our results show that the electro-catalytic honeycomb (ECH) promotes the decomposition of NOx to nitrogen and oxygen, without consuming reagents or other resources. NOx can be converted to nitrogen and oxygen almost completely. The ECHs are shown to effectively remove NOx from gasoline-fueled diesel-like exhausts. A very high NO concentration is preferred in the engine exhaust, especially during engine cold-start. Promoted NOx decomposition (PND) technology for real-world automotive applications is established in this study by using the ECH. With PND, EGR is no longer needed. Diesel-like engines can therefore achieve superior fuel efficiency, and all major automotive pollutants can be easily treated due to high concentration of oxygen in the diesel-like exhausts, leading to zero pollution.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Air Pollutants / analysis
  • Catalysis
  • Electrochemistry / methods*
  • Gasoline*
  • Nitrates / analysis*
  • Nitrites / analysis*
  • Oxygen / analysis
  • Temperature
  • Vehicle Emissions / analysis*

Substances

  • Air Pollutants
  • Gasoline
  • Nitrates
  • Nitrites
  • Vehicle Emissions
  • Oxygen