Why is mno2 a catalyst

Cite this: J. Article Views Altmetric -. Citations 7. Cited By. This article is cited by 7 publications. Journal of Chemical Education , 98 3 , Treatment of polymer-flooding wastewater by a modified coal fly ash-catalysed Fenton-like process with microwave pre-enhancement: System parameters, kinetics, and proposed mechanism.

Chemical Engineering Journal , , Synthesis, crystal structures, catalytic application and antibacterial activities of Cu II and Zn II complexes bearing salicylaldehyde-imine ligands.

Inorganica Chimica Acta , , Reality check: people put gas in their car and drive it down the road without any knowledge of combustion or coefficients of friction. This works because they only wish to drive from point A to point B. This does not work for the mechanic asked to fix the vehicle. People wanting clean water to flow from the faucet do not really care how it happens.

Catalytic precipitation, particle adsorption and mechanical straining are not topics that interest users. This is not a luxury afforded a water treatment specialist.

Manganese dioxide MnO2 is an inorganic compound. It is a black to brown-colored material that occurs naturally as the mineral pyrolusite see Figure 1. In addition to water treatment, MnO2 has many uses, including but not limited to the manufacture of batteries, beverage cans, agricultural pesticides and fungicides and electronic circuitry.

Manganese dioxide technology is one of the most commonly used and least understood applications for removing iron, manganese, hydrogen sulfide, arsenic and radium. Read along and discover that MnO2 is not magic dust, but a very helpful catalyst used to improve water quality in applications from private wells to large municipalities. History of manganese dioxide The use of manganese dioxide goes back 17, years to the upper Paleolithic period when Stone Age men used it as a pigment for their cave paintings.

The Spartans of Ancient Greece used MnO2 in their steel making, thus creating weapons superior to those of their enemies. The Egyptians and the Romans used manganese ore in glass making to give the glass pink, purple and black tints. In the midth century, manganese oxide was a main ingredient in the manufacture of chlorine. In , a German researcher noted that manganese increased the hardness of iron, without compromising its flexibility or strength.

The battery industry is the second largest consumer of manganese today. The uses for MnO2, like many of the technologies used today in water treatment, have a long and storied history. What is a catalyst?

A catalyst is best described as something that drives change. A skier at the top of a grassy ski slope in the summer can slide down the slope and eventually get to the bottom of the hill. At the top of the hill, the skier has the potential, over time, to get to the bottom of the slope. The same skier will have an easier time getting to the bottom of the slope in the winter when the hill is covered in snow, which accelerates the potential.

The snow is the catalyst. It allows the skier to move faster and accelerates the act of reaching the bottom. Abraham Lincoln and the Civil War were both catalysts for change in US policies on secession and slavery. In chemistry, a catalyst causes or accelerates a chemical reaction without itself being affected. In water treatment, MnO2 provides filter media with a catalyst. Manganese dioxide creates a catalytic effect in the chemical oxidation-reduction reactions necessary to remove iron, manganese, H2S, arsenic and radium.

Media using MnO2 Within the water treatment industry, there are a number of media that incorporate MnO2. Following is a brief discussion of some of media utilizing this catalyst, which range from pyrolusite media with a high percentage of MnO2 to lightweight manufactured media with MnO2 coating.

High-MnO2 concentration pyrolusite ore has MnO2 contents to percent. This category of media is heavy, weighing around pounds per cubic foot. The use of enzymes allows some industrial reactions to happen at lower temperatures and pressures than traditionally needed.

Yeast is a single-celled fungus. The enzymes in yeast are used to produce wine, beer and other alcoholic drinks by fermentation of sugars. Catalysts A catalyst is a substance that: increases the rate of a reaction does not alter the products of the reaction is unchanged chemically and in mass at the end of the reaction Only a very small mass of catalyst is needed to increase the rate of a reaction. Catalyst Reaction catalysed Iron Haber process making ammonia Vanadium V oxide Contact process a stage in making sulfuric acid Manganese dioxide Decomposition of hydrogen peroxide produces water and oxygen Notice that these catalysts are transition metals or compounds of transition metals.

How catalysts work A catalyst provides an alternative reaction pathway that has a lower activation energy than the uncatalysed reaction. A reaction profile for a reaction with and without a catalyst Enzymes An enzyme is a biological catalyst. Cited By. This article is cited by 5 publications. John J. Journal of Chemical Education , 91 5 , Journal of Chemical Education , 98 3 , ACS Synthetic Biology , 9 5 , Berkowitz , Martin C.