Katalizator

Katalizator is a substance that increases the rate of a chemical reaction without being consumed in the process. Catalysts work by providing an alternative reaction pathway with lower activation energy, improving speed and efficiency. They are central in many industrial applications and in technologies aimed at reducing pollution. Catalysts can be homogeneous, where the catalyst and reactants are in the same phase, or heterogeneous, typically involving a solid surface where the reaction takes place.

Heterogeneous catalysts are widely used in industry because they can be separated from products and reused. They often rely on solid materials with active sites on their surface, where reactant molecules adsorb, react, and then desorb as products. The choice of material, surface structure, and temperature governs activity, selectivity, and longevity.

In automotive technology, the katalizator refers to the catalytic converter installed in the exhaust system. The most common type is the three-way catalyst, which promotes oxidation of carbon monoxide and hydrocarbons and reduction of nitrogen oxides. It uses noble metals such as platinum, palladium, and rhodium dispersed on a ceramic substrate with a washcoat to increase surface area. Effective operation requires sufficiently high exhaust temperatures and a near-stoichiometric air–fuel ratio. Catalysts are sensitive to sulfur compounds and lead, and can be degraded by overheating or poisoning over time.

History and impact: Conceptual and experimental work in the mid-20th century led to practical catalytic converters, with mass adoption following stricter emissions standards in the 1970s. Catalytic systems have significantly reduced emissions of CO, hydrocarbons, and NOx, contributing to cleaner urban air, while not eliminating greenhouse gas emissions.