Question

____________ is collected during engine startup time when the catalytic converter is cold, and then later released back into the exhaust flow when the converter is hot.

(a) HC

(b) CO

(c) CO2

(d) H2O

I have been asked this question by my college professor while I was bunking the class.

The above asked question is from Reducing Emissions by Chemical Methods topic in chapter Engine Emissions and their Control of IC Engine

Answer 1

The correct answer is:

(a) HC

Hydrocarbons (HC) are collected during engine startup when the catalytic converter is cold, and then later released back into the exhaust flow when the converter heats up. During the startup phase, the converter is not yet effective at converting HC emissions, so they are temporarily stored and later burned off once the converter reaches its operating temperature.