Question

Two Stage Catalytic Convertors are used in vehicles for _____ in tail end emissions.

• A. Oxidation of NO and CO
• B. Oxidation of NO and reduction of CO
• C. Reduction of NO and Oxidation of CO
• D. Reduction of NO and CO

Hint:

Stage 1: NO $\rightarrow$ N$_2$ (reduction). Stage 2: CO $\rightarrow$ CO$_2$ (oxidation). Three-way catalytic converters handle NO, CO, and HC simultaneously.

Answer 1

The Correct Option is C

Step 1: Concept
Function of two-stage catalytic converters.

Step 2: Meaning
A catalytic converter reduces harmful exhaust emissions through catalysed chemical reactions.

Step 3: Analysis
Stage 1 (Reduction catalyst --- Rh/Pt): NO $\rightarrow$ N$_2$ + O$_2$ (reduction of NO).
Stage 2 (Oxidation catalyst --- Pt/Pd): CO $\rightarrow$ CO$_2$ and HC $\rightarrow$ CO$_2$ + H$_2$O (oxidation of CO).
Hence the two-stage catalytic converter performs reduction of NO and oxidation of CO.

Step 4: Conclusion
Two-stage catalytic converters: Stage 1 reduces NO; Stage 2 oxidises CO. Final Answer: (C)