Question

Catalytic converters fitted in vehicles are used for\(\underline{\hspace{6cm}}\).

• A. oxidation of NO\(_x\), CO and hydrocarbons.
• B. oxidation of CO and reduction of NO\(_x\).
• C. reduction of CO\(_2\) and oxidation of NO.
• D. oxidation of CO, and reduction of NO\(_2\) and volatile organic carbons.

Hint:

Remember the mnemonic "NOx is reduced, CO/HC are oxidized". The goal is to turn harmful gases (NOx, CO, HC) into harmless ones (N\(_2\), CO\(_2\), H\(_2\)O).

Answer 1

The Correct Option is D

Step 1: Concept Definition:
A catalytic converter is a device in vehicle exhaust systems designed to reduce harmful emissions. It achieves this by converting toxic gases and pollutants from internal combustion engines into less toxic substances through redox reactions.

Step 3: Functional Breakdown:
Modern three-way catalytic converters perform three concurrent chemical processes:
1. Reduction of Nitrogen Oxides (NO\(_x\)) to Nitrogen Gas (N\(_2\)): This is a reduction process. (Example: \(2NO\rightarrow N_2 + O_2\))2. Oxidation of Carbon Monoxide (CO) to Carbon Dioxide (CO\(_2\)): This is an oxidation process. (Example: \(2CO + O_2\rightarrow 2CO_2\))3. Oxidation of Unburnt Hydrocarbons (HC) to Carbon Dioxide (CO\(_2\)) and Water (H\(_2\)O): This is also an oxidation process.
In summary, the primary functions of a catalytic converter involve the oxidation of CO and hydrocarbons, and the reduction of NO\(_x\).

Step 4: Concise Summary:
Catalytic converters facilitate the oxidation of CO (and hydrocarbons) and the reduction of NO\(_x\).