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Liang-Hai Sie

How does MnO2 act as a catalyst?

Dallas Hall's Space  Follow

To examine MnO2 as a catalyst requires reviewing extensive information on reaction mechanisms and reaction kinetics. In general a catalyst lowers the activation energy needed to make a proceed. Usually an intermediate species is formed, and reactants move from ground state to an activated state with MnO2 providing a surface or a new unstable species in which MnO2 provides a bridge area exposing bonding sites for attracting atoms from second reactant species, or a large reactant molecule now exposing a new atom, ion or free radical, or a combination of these. This is where an activated unstable species forms. The catalyst reduces the input energy one would normally need and saves energy, and speeds up the reaction. Some reactions may be impossible without a catalyst under lab or industrial conditions. This activated intermediate is like an embryo, which proceeds to product formation by releasing energy, and new product derived from the original reactant(s). MnO2 is used as a catalyst in a few chemical processes and the steps vary, in respective reactions. But in general Reaction Kinetics and Reaction Mechanism determination is a science in itself. Surface Chemistry catalysis is a branch of chemistry separate and distinct now much like , Organic, Physical, … Chemistry.

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David Walters, Ph.D.  Follow

Manganese dioxide catalyzes the decomposition of hydrogen peroxide to oxygen and water. With the addition of the synthesized catalyst, MnO2, we can actually lower this activation energy down to about 58 KJ/mole (Moelwyn-Hughes) and that speeds up the decomposition by 1073 times at 200C

Potassium chlorate(KClO3) liberates oxygen on thermal decomposition but the reaction rate is slow but in presence of manganese dioxide (MnO2) the rate enhances and hence manganese dioxide acts as a positive catalyst in this particular reaction.

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Alexander Streng  Follow

A catalyst is a substance that speeds up the rate of a chemical reaction but is not consumed during the course of the reaction. A catalyst will appear in the steps of a reaction mechanism, but it will not appear in the overall chemical reaction.

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Dale Henderson  Follow

The general principle on the action of a catalyst is that it helps to lower the Activation Energy of the reaction. It helps in the formation of the Activated Complex that decomposes into products and leaves the catalyst unchanged.

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Brett Fox  Follow

Among all the transition metal oxides, MnO2, which exhibits stable performance in supercritical water oxidation (SCWO), has a relatively high catalytic activity in the catalytic decomposition of organic compounds by oxidation. Hence, for some organics that are difficult to degrade, MnO2 is a commonly used catalyst.

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Bob Myers  Follow

MnO2 is an Oxidizing agent and MnO is a reducing agent. Manganese is not truly catalytic because it is involved in reaction. In decomposing Hydrogen Peroxide it first oxidizes one Peroxide molecule then oxidized back by another.

Similar in Manganese Dioxide Potassium Chlorate Oxygen generation. The Chlorate oxidizes the Manganese Dioxide then it decomposes exothermically at ~350° instead of KClO3 decomposing by itself at higher Temp.

True catalyst would be oxidizing Sulfur Dioxide with Oxygen over Platinum catalyst where the Platinum catalyst is unchanged.

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Anthony John Finch  Follow

Hydrogen peroxide decomposes slowly to produce oxygen and water under normal conditions. On adding manganese IV oxide the rate of decomposition is speeded up. Manganese IV oxide acts as catalyst. A catalyst is a substance that alters the rate of reaction. It act best when in powder form.Manganese IV oxide is used as catalyst in the decomposition of hydrogen peroxide.

Manganese IV oxide increases the rate of reaction through increasing activation energy ( Ea). Activation energy is the minimum amount of kinetic energy that the reacting particles must have to form products

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Baba Vickram Aditya Bedi  Follow

Manganese dioxide catalyzes the deterioration of hydrogen peroxide to oxygen and water. ... With the expansion of the orchestrated impetus, MnO2, we can really let this initiation energy down to around 58 KJ/mole (Moelwyn-Hughes) and that paces up the deterioration by multiple times at 200C.

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