Catalysis
In 1794, chemist Elizabeth Fulhame published a book describing how certain substances could speed up reactions without being consumed. Her work on oxidation-reduction experiments laid the foundation for what we now call catalysis. The term itself comes from the Greek word kataluein, meaning to loosen or untie. This concept describes a process where an added substance increases the rate of a chemical reaction while remaining unchanged after the event. A small amount of catalyst can suffice if the reaction is rapid and the catalyst is recycled quickly. Factors like mixing, surface area, and temperature play critical roles in determining the final reaction rate.
Catalysts fall into distinct categories based on their physical state relative to reactants. Homogeneous catalysis occurs when components are dispersed in the same phase as the reactant molecules, usually gaseous or liquid. Heterogeneous catalysis involves components that exist in different phases, such as solid catalysts acting on substrates in a liquid or gas mixture. Enzymes and other biocatalists often form a third category within this framework. Most heterogeneous catalysts are solids that interact with substrates dissolved in liquids or gases. The total surface area of a solid catalyst significantly impacts the reaction rate because smaller particle sizes create larger surface areas for a given mass.
Estimates suggest that 90% of all commercially produced chemical products involve catalysts at some stage during manufacture. In 2005 alone, these processes generated approximately $900 billion worth of products worldwide. Petroleum refining relies heavily on catalytic cracking to break long-chain hydrocarbons into smaller pieces. Catalytic converters containing platinum and rhodium treat exhaust from burning fossil fuels by breaking down harmful byproducts like carbon monoxide. The Haber process combines nitrogen and hydrogen over an iron oxide catalyst to produce ammonia, one of the largest-scale industrial reactions. Sulfuric acid production uses vanadium pentoxide to convert sulfur dioxide into sulfur trioxide through the contact process.
Elizabeth Fulhame invented the concept of catalysis based on her novel work in oxidation-reduction experiments published in 1794. Gottlieb Kirchhoff studied the first organic chemistry reaction using a catalyst in 1811 when he discovered the acid-catalyzed conversion of starch to glucose. Jöns Jakob Berzelius coined the term katalys (catalysis) in 1835 while reviewing research on ether formation. Wilhelm Ostwald began systematic investigations into acid- and base-catalyzed reactions at Leipzig University in the 1880s. He found that chemical reactions occur at finite rates and used these rates to determine acid and base strengths. This work earned him the 1909 Nobel Prize in Chemistry. Vladimir Ipatieff performed some of the earliest industrial scale reactions including oligomerization discovery.
Electrocatalysts enhance half-reaction rates within fuel cell engineering using platinum nanoparticles supported on carbon particles. Photocatalysts receive light to generate excited states that effect redox reactions, often producing singlet oxygen. Organocatalysts are small organic molecules without metals that exhibit catalytic properties similar to metal-free enzymes. The Nobel Prize in Chemistry 2021 recognized Benjamin List and David W.C. MacMillan for developing asymmetric organocatalysis. Switchable catalysis allows catalysts to toggle between different ground states possessing distinct reactivity through external stimuli like temperature or pH changes. These specialized systems enable precise control over reaction activity and selectivity in modern technology applications.
Enzymes serve as protein-based catalysts in biological metabolism and catabolism processes. Most biocatalysts are enzymes though other nonprotein classes like ribozymes also exhibit catalytic properties. Chlorine free radicals play a notable role in ozone breakdown by reacting with ultraviolet radiation on chlorofluorocarbons. Catalytic converters remove toxic gases from automobile exhaust while converting them into less harmful substances. Enzymes prepare commodity chemicals including high-fructose corn syrup and acrylamide. Monoclonal antibodies can function as weak catalysts by lowering activation energy when their binding target resembles the transition state of a chemical reaction.
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Common questions
Who published the first book describing catalysis in 1794?
Elizabeth Fulhame published a book in 1794 that described how certain substances could speed up reactions without being consumed. Her work on oxidation-reduction experiments laid the foundation for what we now call catalysis.
What is the origin of the word catalysis and its meaning?
The term catalysis comes from the Greek word kataluein which means to loosen or untie. This concept describes a process where an added substance increases the rate of a chemical reaction while remaining unchanged after the event.
When did Gottlieb Kirchhoff study the first organic chemistry reaction using a catalyst?
Gottlieb Kirchhoff studied the first organic chemistry reaction using a catalyst in 1811 when he discovered the acid-catalyzed conversion of starch to glucose. This discovery marked a significant milestone in early catalytic research.
Which scientist won the Nobel Prize in Chemistry in 1909 for work on reaction rates?
Wilhelm Ostwald earned the 1909 Nobel Prize in Chemistry for his systematic investigations into acid- and base-catalyzed reactions at Leipzig University. He found that chemical reactions occur at finite rates and used these rates to determine acid and base strengths.
How much value did catalytic processes generate worldwide in 2005?
In 2005 alone, catalytic processes generated approximately $900 billion worth of products worldwide. Estimates suggest that 90% of all commercially produced chemical products involve catalysts at some stage during manufacture.