15.3.1 Heterogeneous Catalysis

• Heterogeneous catalysis occurs when the catalyst and reactants are in different phases
• Steps in the mechanism of heterogeneous catalysis

  1️⃣ Adsorption

  2️⃣ Surface Reaction

  3️⃣ Desorption
• In heterogeneous catalysis, the catalyst and reactants are in the same phase.

  False
• In heterogeneous catalysis, the catalyst is easy to recover
• Match the type of catalysis with an example:

  Heterogeneous ↔️ Haber-Bosch process

  Homogeneous ↔️ Esterification using acid catalysts
• Partially filled d-orbitals in transition metals allow efficient electron transfer during reactions.
• Transition metals exhibit variable oxidation states
• What does a high surface area of a transition metal catalyst maximize?

  Contact with reactants
• The Haber-Bosch process uses iron catalysts to produce ammonia.
• Which metals are used in catalytic converters in cars?

  Platinum, palladium, rhodium
• In heterogeneous catalysis, reactant molecules are attracted to the catalyst's surface
• What is the catalyst used in the Haber-Bosch process?

  Iron
• In the Haber-Bosch process, nitrogen reacts with hydrogen to produce ammonia
• Platinum, palladium, and rhodium are used in catalytic converters to reduce toxic emissions in cars.
• What is produced when carbon monoxide reacts with oxygen in a catalytic converter?

  Carbon dioxide
• In heterogeneous catalysis, the first step is adsorption
• Active sites on the catalyst surface are optimized for efficient reaction.
• Which metal is commonly used as a catalyst in hydrogenation?

  Nickel
• The thermal stability of heterogeneous catalysts allows operation at high temperatures.
• Steps of heterogeneous catalysis in the correct order:

  1️⃣ Adsorption

  2️⃣ Surface Reaction

  3️⃣ Desorption
• In homogeneous catalysis, the catalyst and reactants are in the same phase
• What is the chemical equation for the Haber-Bosch process?

  $N_{2}(g) +$$3H_{2}(g) \rightleftharpoons 2NH_{3}(g)$
• Match the property of transition metals with its role in catalysis:

  Partially filled d-orbitals ↔️ Efficient electron transfer

  Variable oxidation states ↔️ Flexible chemical transformations

  High surface area ↔️ Maximizes reactant contact

  Complex formation ↔️ Bonds reactants to surface
• Iron catalysts in the Haber-Bosch process are used to produce ammonia.
• Which transition metals are used in catalytic converters?

  Platinum, palladium, rhodium
• In heterogeneous catalysis, the rate of reaction is generally faster than in homogeneous catalysis.
• A large surface area of the catalyst in heterogeneous catalysis leads to high reaction rates.
• Why is easy catalyst recovery an advantage of heterogeneous catalysis?

  Simplifies purification
• Match the advantage of heterogeneous catalysis with its explanation:

  High Reaction Rates ↔️ Large catalyst surface area

  Easy Catalyst Recovery ↔️ Phase separation simplifies removal

  Thermal Stability ↔️ Operates at high temperatures
• What is an example of a process that uses the thermal stability of heterogeneous catalysis?

  Steam reforming of methane
• In the Haber-Bosch process, iron catalysts are easily recovered and reused.
• Heterogeneous catalysis results in high reaction rates due to the large surface area of the catalyst
• The easy recovery of the catalyst in heterogeneous catalysis simplifies the purification process
• Heterogeneous catalysts can operate at high temperatures without degrading.
• What is an example of a process where a heterogeneous catalyst with high reaction rates is used?

  Catalytic converters in cars
• Which catalyst is used in the Haber-Bosch process to demonstrate easy catalyst recovery?

  Iron
• Steam reforming of methane, which operates at 700-1000°C, showcases the thermal stability of heterogeneous catalysis
• Catalyst deactivation in heterogeneous catalysis can occur due to poisoning or fouling.
• What is one limitation of heterogeneous catalysis that results in slow diffusion of reactants to active sites?

  Mass transport limitations
• High temperature and pressure are often necessary in heterogeneous catalysis to achieve efficient reaction rates.