Due to the rapid growth of industry, catalytic reactions are becoming more and more in demand in chemical production, mechanical engineering, and metallurgy. Thanks to the use of catalysts, it is possible to turn low-grade raw materials into a valuable product.
Significance
Catalytic reactions are distinguished by the variety of agents used. In organic synthesis, they contribute to a significant acceleration of dehydrogenation, hydrogenation, hydration, oxidation, and polymerization. The catalyst can be considered a "philosopher's stone" that turns raw materials into finished products: fibers, drugs, chemicals, fertilizers, fuels, plastics.
Catalytic reactions make it possible to obtain numerous products, without which normal life and human activity are impossible.
Catalysis allows you to speed up processes inthousands and millions of times, which is why it is currently used in 91% of various chemical industries.
Interesting facts
Many modern industrial processes, such as the synthesis of sulfuric acid, can only be carried out using a catalyst. A wide variety of catalytic agents ensures the creation of motor oils for the automotive industry. In 1900, for the first time on an industrial scale, a catalytic synthesis of margarine from vegetable raw materials (by hydrogenation) was carried out.
Since 1920, a mechanism has been developed for catalytic reactions in the production of fibers and plastics. A landmark event was the catalytic production of esters, olefins, carboxylic acids, as well as other starting materials for the manufacture of polymer compounds.
Oil refining
Since the middle of the last century, catalytic reactions have been used in oil refining. The processing of this valuable natural resource involves several catalytic processes at once:
- reforming;
- cracking;
- hydrosulfonation;
- polymerization;
- hydrocracking;
- alkylation.
Since the end of the last century, it has been possible to develop a catalytic converter to reduce exhaust emissions into the atmosphere.
Several Nobel Prizes have been awarded for work in catalysis and related fields.
Practical relevance
A catalytic reaction is any process that involves the use of accelerators (catalysts). To assess the practical significance of such interactions, one can cite as an example the reactions associated with nitrogen and its compounds. Since this amount is very limited in nature, the creation of food protein without the use of synthetic ammonia is very problematic. The problem was solved with the development of the Haber-Bosch catalytic process. The use of catalysts is constantly expanding, which makes it possible to increase the efficiency of many technologies.
Ammonia production
Let's consider some catalytic reactions. Examples from inorganic chemistry are given on the basis of the most common industries. The synthesis of ammonia is an exothermic, reversible reaction, which is characterized by a decrease in the volume of the gaseous substance. The process takes place on a catalyst, which is porous iron with the addition of aluminum oxide, calcium, potassium, silicon. Such a catalyst is active and stable in the temperature range of 650-830K.
Irreversibly send it sulfur compounds, in particular carbon monoxide (CO). Over the past few decades, thanks to the introduction of innovative technologies, the pressure has been significantly reduced. For example, a converter was made that allows you to lower the pressure indicator to 8106 - 15106 Pa.
Modernization of the front circuit has significantly reduced the likelihood of finding catalytic poisons in it - sulfur compounds,chlorine. The requirements for the catalyst have also increased significantly. If earlier it was produced by melting iron oxides (scale), adding magnesium and calcium oxides, now cob alt oxide plays the role of a new activator.
Oxidation of ammonia
What are the characteristics of catalytic and non-catalytic reactions? Examples of processes that depend on the addition of certain substances can be considered based on the oxidation of ammonia:
4NH3+ 5O2=4NO+ 6H2O.
This process is possible at a temperature of about 800°C, as well as a selective catalyst. To accelerate the interaction, platinum and its alloys with manganese, iron, chromium, and cob alt are used. Currently, the main industrial catalyst is a mixture of platinum with rhodium and palladium. This approach made it possible to significantly reduce the cost of the process.
Water decomposition
Considering the equations of catalytic reactions, one cannot ignore the reaction of obtaining gaseous oxygen and hydrogen by water electrolysis. The process involves significant energy costs, so it is used infrequently on an industrial scale.
Metal platinum with a particle size of about 5-10 nm (nanoclusters) acts as an optimal accelerator for such a process. The introduction of such a substance accelerates the decomposition of water by 20-30 percent. Other benefits include the stability of the platinum carbon monoxide catalyst.
In 2010a team of American scientists received a cheap catalyst that reduces energy consumption for water electrolysis. They became a compound of nickel and boron, the cost of which is significantly lower than platinum. The boron-nickel catalyst has been appreciated in the production of industrial hydrogen.
Synthesis of aluminum iodide
Get this s alt by reacting aluminum powder with iodine. One drop of water is enough to act as a catalyst to initiate a chemical reaction.
First, the aluminum oxide film acts as an accelerator of the process. Iodine, dissolving in water, forms a mixture of hydroiodic and iodic acids. The acid, in turn, dissolves the aluminum oxide film, acting as a catalyst for the chemical process.
Summarize
Every year, the scale of application of catalytic processes in various areas of modern industry is increasing. Catalysts are in demand that allow you to neutralize substances that are hazardous to the environment. The role of compounds necessary for the manufacture of synthetic hydrocarbons from coal and gas is also growing. New technologies help reduce energy costs in the industrial production of various substances.
Thanks to catalysis, it is possible to obtain polymer compounds, products with valuable properties, modernize technologies for converting fuel into electrical energy, synthesize substances necessary forhuman life and activities.
