Catalysts in industrial processes: elements vs. compounds

Steps:

• Recall the catalyst for each process: catalytic converters use platinum/palladium; Contact process uses vanadium pentoxide; Haber process uses iron; hydrogenation uses nickel.
• Classify each catalyst: metals like Pt, Pd, Fe, Ni are elements; V₂O₅ is a compound.
• Compare to question: identify the process using a compound over an element.
• Confirm via standard chemical definitions: compounds contain multiple elements bonded, unlike pure metals.

Why B is correct:

• The Contact process catalyzes SO₂ to SO₃ using vanadium(V) oxide (V₂O₅), a compound that lowers activation energy per the Arrhenius equation.

Why the others are wrong:

• A: Catalytic converters use platinum, palladium, and rhodium metals (elements) to convert exhaust gases.
• C: Haber process uses finely divided iron (element) with oxide promoters for ammonia synthesis.
• D: Hydrogenation of alkenes uses Raney nickel (element) to add H₂ across double bonds.

Final answer: B