What is the catalyst of motorcycle indicator of quality assessment of 1?
Answer: evaluation of motorcycle catalyst performance indicators are: 1 ) the light-off temperature – under certain conditions, catalyst conversion of some pollutants rate reached 50% when the temperature; 2 ) conversion – under certain conditions, the catalyst conversion of some pollutants rate; 3 ) durability – catalyst continued effective use time or mileage; 4 ) the air-fuel ratio – in a variety of air-fuel ratio conversion rate under conditions.
In general, catalyst light-off temperature is lower, the conversion rate is high, durable time or mileage longer, wider than the air-fuel properties window, the better the performance of the catalysts.
Catalyst 2 contains 2 kinds of precious metal composition of the catalyst is two yuan, contains 3 kinds of precious metal catalyst is three yuan, this statement correct?
Answer: This is wrong.
In the exhaust gas of gasoline engine, mainly containing CO ( carbon monoxide ), HC ( hydrocarbons ) and NOX ( nitrogen oxides ) 3 kinds of harmful components, as well as harmless CO2 ( carbon dioxide ), H2O ( water vapor ), O2 ( oxygen ) and N2 ( N2 )
Early automobile and motorcycle emission control requirements, only need to reduce exhaust CO and HC, the researchers found that high O2 content in exhaust conditions, using Pt or Pt-Pd catalyst can efficiently remove CO and HC at the same time, the catalytic effect is two effective, and the corresponding catalyst known as the two element of catalysts or catalyst; with the emission standards, requirements for the control of these 3 kinds of CO, HC and NOX harmful components, through the study found that Pt-Rh catalyst fuel ratio in the theoretical air-fuel ratio near 14.6 in the engine air, can simultaneously efficient removal of CO, HC and NOX these 3 kinds of harmful substances at this time, a catalytic effect is three effective, and the corresponding catalyst called three catalyst, and later have developed Pt-Pd-Rh, single Pd catalyst, which has the same catalytic purification effect, also is three yuan catalytic agent.
In the modern theory of catalysis and preparation of scientific guidance, people can design according to the specific object catalyst governance and requirements, can be the excellent performance of the two yuan and the catalyst was prepared efficiently design and system design, and the catalyst preparation depends on the governance objectives and requirements.
Conditions of use are important factors to affect the transformation effect of catalyst, such as the Pt-Rh three catalyst for lean-burn engine exhaust can purify CO, HC, and NOX without purification effect; oxidized Pt-Pd catalyst under oxygen-enriched condition in the exhaust gas oxygen depleted engine also show the purification effect of three certain of effect. Catalyst three properties is the actual catalyst than a narrow ranges near can also give full play to efficient transformation effect on CO, HC and NOX in the theoretical air-fuel, this usually requires the EFI engine to precise control of air-fuel ratio, so the assembly for electronic fuel injection engine automobile universal is used in three way catalyst; on the motorcycle, emissions exceed the standard is CO and HC the 2 main components, and the motorcycle is basically a carburetor, so the catalyst design and actual application conditions make the catalyst more performance for two yuan, but this is not to say that the catalyst itself is two yuan in the catalyst, mixture concentration conditions, catalyst the NOX also to be purified, also exhibit characteristics of three yuan.
Therefore, we say that is two yuan or three yuan catalyst not directly related with the types and proportion of containing precious metal, which contains 2 kinds of precious metal catalyst, that is two yuan with 3 kinds of precious metal catalyst is three yuan is wrong, in fact is the catalyst design and application condition determines the catalyst is two yuan or three yuan