Heavy duty trucks exhaust emissions

Table 12. Federal Heavy-Duty Truck Exhaust Emission Standards, g/(kWh) ...

In the past, exhaust emission standards (limits) have been set in most industrialised countries for passenger cars, light-duty trucks and heavy-duty trucks (gasoline and diesel... 

In addition to their primary fimction of reducing particulate matter, diesel catalysts must convert gas phase CO and HC. Emission limits have come down sharply for U.S. trucks, for example, 2009 standards allow only about 1/10 as much as HC as was permitted in 1994. For CO, 2003/2004 limits for Japanese heavy-duty trucks are about 1/3 of their values in 2000. The much leaner diesel exhaust, compared with gasoline exhaust, helps reduce CO and HC emissions, but diesel exhaust is generally cooler, which suppresses conversion. Low temperature activity is, accordingly, are research priority. Pt, or Pt/Pd, supported on alumina, is standard, but even small changes in thermal stability can confer a competitive advantage. 

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