Intermediate Topic 452 of 1102 Kinetics & Equilibrium
Heterogeneous Catalysis
The catalyst is in a different phase, typically a solid surface with gaseous reactants.
Practise Kinetics & Equilibrium All Kinetics & Equilibrium topics
In-depth explanation of Heterogeneous Catalysis
In heterogeneous catalysis the catalyst is a solid, while the reactants are gases or liquids that react at the solid surface. The process involves adsorption of reactants onto active sites, reaction on the surface and then desorption of products back into the fluid. Heterogeneous catalysts are easy to separate from the reaction mixture and can be reused, which makes them very important in industry. Their performance depends on surface area, the nature of the active sites and the strength of adsorption, since adsorption that is too weak or too strong reduces activity.
Going deeper: Heterogeneous Catalysis
Key ideas: Surface catalysis needs moderate adsorption: the Sabatier principle says the bond to the surface should be strong enough to activate reactants but weak enough to release products. Reaction rates often reach a maximum at intermediate coverage. Promoters like potassium in the Haber catalyst enhance activity, while supports disperse the metal to raise area.
Common mistakes and connections: Students think the solid catalyst is inert or that it only increases the area. It chemically binds reactants and changes the pathway. Another mistake is confusing adsorption, which is surface accumulation, with absorption into the bulk. Catalyst deactivation by poisoning, sintering or coking lowers rates over time. Links to surface area effects and Langmuir-Hinshelwood mechanisms.
Visualization of Heterogeneous Catalysis
Metal catalysts such as Pt, Pd and Ni have close-packed face-centred cubic surfaces where reactant molecules adsorb, react and desorb. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Iron catalyses the Haber process, and platinum or palladium catalyses the oxidation of carbon monoxide in automobile catalytic converters.
Frequently asked questions about Heterogeneous Catalysis
What is Heterogeneous Catalysis?
The catalyst is in a different phase, typically a solid surface with gaseous reactants.
Is Heterogeneous Catalysis a beginner, intermediate or advanced topic?
Heterogeneous Catalysis is a intermediate topic in Kinetics & Equilibrium. It builds on the vocabulary of beginner topics in this area.
What should I learn before Heterogeneous Catalysis?
Study these earlier topics in Kinetics & Equilibrium first: Effect of Surface Area, Catalyst, Homogeneous Catalysis.
What comes after Heterogeneous Catalysis?
The next topics in Kinetics & Equilibrium are Enzyme Catalysis and Michaelis-Menten Kinetics.
Can I practise Heterogeneous Catalysis with quizzes?
Yes. The interactive lesson includes a self-check question on Heterogeneous Catalysis, and the Kinetics & Equilibrium quiz draws on every topic in this area.
Where Heterogeneous Catalysis fits in Kinetics & Equilibrium
Heterogeneous Catalysis is topic 33 of 91 in Kinetics & Equilibrium.