Questions about hydrogen peroxide catalysts

Experiments have been tried: potato shavings, copper sulfate, red brick powder, pork liver, and soot are all available, but except for manganese dioxide and pork liver, others need to be heated.

Hydrogen peroxide can decompose at room temperature to produce oxygen and water (slow decomposition), and can accelerate the reaction after heating or adding catalysts, such as manganese dioxide, copper sulfate, hydrogen iodide, lead dioxide, ferric chloride, and catalase in living organisms.

When manganese dioxide is used as a catalyst, the most recognized reaction principle is: H2O2+Mno2=H2Mno4 (δH<0) H2mNO4+H2O2= Mno2+2H2O+ O2 The catalytic hydrogen peroxide decomposition principle is that H2O2 is used as an oxidant first, and then as a reducing agent.

Let me give you a systematic introduction to hydrogen peroxide!

An aqueous solution of hydrogen peroxide is also commonly known as hydrogen peroxide. Pure hydrogen peroxide has a melting point of -1 degrees Celsius and a boiling point of 150 degrees Celsius.

High-purity hydrogen peroxide is relatively stable at low temperatures, and the decomposition is relatively stable. When heated to more than 426K, a strong ** decomposition occurs: 2H2O2==2H2O+O2

Hydrogen peroxide at concentrations higher than 65% is prone to occur when it comes into contact with certain organic substances**.

The decomposition rate of H2O2 in alkaline media is much greater than in acidic media. The presence of a small amount of Fe2+, Cu2+, Mn2+, Cr3+ and other metal ions can greatly accelerate the decomposition of H2O2. Light also accelerates the decomposition of H2O2.

Therefore, H2O2 is kept in a brown bottle in a cool place.

H2O2 is a very weak acid, K1=, K2 is about 10 -25.

H2O2 can react with certain metal hydroxides to form peroxides and water. For example, H2O2+BA(OH)2==Bao2+2H2O

This reaction is similar to acid-base neutralization.

The rest has little to do with what you asked, so I won't copy it!

For your question, I would like to summarize that the catalysts of H2O2 include MNO2 (metal oxide, and there is only one of them), biological enzymes (pig liver, catalase in liver), light (only catalytic, not a catalyst), metal cations (there are many types).

As for the catalytic process and intermediates, it's complicated!

Hope it helps!!

The experiment compares the efficiency of catalysts: the conclusion is that in general, biological catalysts are more efficient than chemical catalysts, and the conditions required are milder. Others were not taken into account.

The catalytic mechanism is relatively complex, and the catalyst has the characteristics of specificity and high efficiency, and has relevant professional knowledge.

In the middle school stage, it is generally only necessary to know that the catalyst can reduce the active energy of the reaction and increase the reaction rate by changing the reaction path. The reaction mechanism does not need to be mastered.

What happens to hydrogen peroxide under catalyst conditions?

Hydrogen peroxide to oxygen catalyst: heavy metal oxides, such as copper oxide, manganese oxide, ferric oxide, etc., even with pig liver, its organocatalyst catalase is also good catalytic.

Hydrogen peroxide itself is not combustible, but it can react with combustibles to release a large amount of heat and oxygen and cause ignition**. Hydrogen peroxide is the most stable at pH, is easy to decompose in alkaline solutions, and can also decompose when exposed to strong light, especially short-wave rays. When heated to more than 100 degrees, it begins to decompose sharply.

h can be used as a catalyst for the decomposition of hydrogen oxide solution instead of manganese dioxide.

Because the catalyst has the characteristic of "one change, two unchanged", that is, "change the rate of chemical reaction; Before and after the reaction, its own mass and chemical properties do not change", so to prove that H has a catalytic effect, it is necessary to prove these three properties, so three experiments should be done, and the following operations should be carried out respectively:

Procedure: a（1）

Procedure: A small amount of hydrogen peroxide liquid is taken into a test tube and a wooden strip with sparks is inserted inward.

Experimentation: The strips did not rekindle.

2) Experimental procedure: Add x g h to the above test tube, and then extend inward into a wooden strip with sparks.

Experimental Phenomenon: The wooden strip has rekindled.

This experiment shows that h can change the reaction rate of hydrogen peroxide decomposition).

b.Experimental procedure: The solids in the test tube after the above reaction are dissolved, filtered, washed, and dried. (thus obtaining the remaining h after the reaction from the tube) to weigh the resulting solids.

Weighing result: h is still x grams.

This experiment shows that the mass of h does not change before and after the reaction).

c.Procedure: Take a small amount of hydrogen peroxide solution into another test tube, and add the remaining H after the previous experiment to the test tube again. Then a sparkled stick of wood is inserted into the tube.

Experimental Phenomenon: Re-ignition of wooden strips.

This test shows that the chemical properties of h before and after the reaction have not changed, and it can still catalyze the decomposition of hydrogen peroxide).

To sum up, it can be obtained.

Results: h has a catalytic effect on the decomposition of hydrogen peroxide.

There are several catalysts for this reaction.

Fe(+III) salts can catalyze the decomposition of hydrogen peroxide.

MNO2 can also be catalyzed as a common catalyst.

Organocatalyst catalase [present in the liver of animals].

Wastewater treated with used catalysts may contain contaminants such as organic matter and heavy metals, which need to be recycled. Hydrogen peroxide is a commonly used regenerative agent, which can effectively oxidize and decompose organic matter, and can also reduce and precipitate heavy metal ions. However, the regeneration time of a used catalyst can be affected by a variety of factors, such as the type of catalyst, the degree of contamination of the wastewater, the concentration of hydrogen peroxide, and so on.

Therefore, the specific processing time needs to be determined according to the actual situation.

In general, when a used catalyst treats wastewater, the catalyst can be regenerated by placing the catalyst in a solution containing hydrogen peroxide. The treatment time can be determined based on the degree of contamination of the wastewater and the state of the catalyst. Normally, the processing time of the pants is about a day.

During the treatment process, it is necessary to regularly check the water quality of the wastewater and the state of the catalyst to ensure the treatment effect and the regeneration efficiency of the catalyst.

It should be noted that when carrying out catalyst regeneration treatment, it is necessary to follow the relevant safety operating procedures to avoid contact between hydrogen peroxide and catalyst, which can cause dangerous chemical reactions. At the same time, the treated wastewater also needs to be treated and discharged to ensure that it does not pollute the environment.

Catalysts such as PT, AG, CR, MNO2, FeCl3, Cuo, and catalase can accelerate the catalytic decomposition of hydrogen peroxide.

1. Hydrogen peroxide has peroxide bonds, and -o-o-medium o is not the lowest oxidation state, so it is unstable and easy to break. The decomposition of hydrogen peroxide can be accelerated by light irradiation with a wavelength of 320 to 380 nm at room temperature, or by heating, and by using catalysts.

2. The catalysis of hydrogen peroxide is mainly as follows:

1) Heavy metal oxides, the resulting substances immediately separate and release oxygen.

Example: H2O2+Mno2=H2Mno4

h2mno4+h2o2=mno2+o2+2h2o

2) Hydrogen peroxide is easy to decompose into oxygen and water under alkaline conditions, and hydroxide makes the solution alkaline, which is conducive to the content of hydrogen peroxide.

Untie. Because soluble alkalis are generally highly corrosive, insoluble alkalis are unstable and costly, this practice is generally not adopted.

3) Catalase catalase: The catalase solution is catalyzed by shredded potatoes, indicating that the catalase continuously produced in organisms can promote the rapid decomposition of H2O2, which is widely present in animal and plant tissues.

4) Metal salt solution: copper sulfate solution has no obvious catalytic phenomenon, and ferric chloride solution has obvious phenomenon, and the rate is similar to the catalytic phenomenon of ferric oxide.

Similar example: What substances can be used as catalysts for the decomposition of hydrogen peroxide?

Hydrogen peroxide generally refers to hydrogen peroxide, the chemical formula of hydrogen peroxide is H2O2, pure hydrogen peroxide is a light blue viscous liquid, which can be miscible with water in any proportion, is a strong oxidizing agent, and the aqueous solution is commonly known as hydrogen peroxide, which is a colorless and transparent liquid. Its aqueous solution is suitable for medical wound disinfection, environmental disinfection and food disinfection. In general, it will slowly decompose into water and oxygen, but the decomposition rate is extremely slow, and the way to speed up the reaction is to add catalysts such as manganese dioxide or irradiate it with short-wave rays.

There are several categories of catalysts:

Oxides of transition elements, such as chromium oxide Cr2O3, manganese oxide MnO2, iron oxide Fe2O3, cobalt oxide Coo, nickel oxide NiO, copper oxide CuO, cuprous oxide Cu2O, zinc oxide Zno

Salts of transition elements, such as manganese sulfate, MnSO4, chromium sulfate, CrSO4, copper chloride CuCl2

Metals such as platinum PT, gold AU

Non-metals, such as phosphorus, activated carbon C, sulfur

Strong bases, such as sodium hydroxide Naoh, potassium hydroxide KOH

Sundries: such as potatoes, porcelain tiles, ink, tree bark, etc.

1. Salt solutions or oxides of all transition metals such as manganese dioxide, copper oxide, copper sulfate, ferric oxide, ferric chloride, etc.;

Red brick powder, biological catalase (can be extracted in the heart of the liver) of which catalase has the best effect (high efficiency of biological catalysts) The potassium permanganate mentioned upstairs should be oxidized by hydrogen peroxide, and the peroxidation stops as a reducing agent, and potassium permanganate is an oxidizing agent rather than a catalyst.

The upstairs one is well said.

There is also an iron chloride solution that can also play a catalytic role.

Potassium permanganate is also fine. The reaction is very violent, and you can check this out.

Manganese dioxide, copper oxide, ferric oxide.

Red brick powder. Catalase.

Among them, catalase has the best effect, manganese dioxide has a good effect, and red brick powder is poor, but it can play a catalytic role.

Inorganic mongolic dioxide, iron ions, copper ions.

Organic catalase.

Ethylene glycol reacts with oxygen, the catalyst is generally copper-silver, the catalyst does not participate in the reaction, and the chemical formula of the reaction is:

Ho-H2C-CH2-OH +O2 catalyzes the oxidation of HoC-CoH + 2H2O

Ethylene glycol is added with concentrated sulfuric acid as a catalyst to esterify ethylene glycol ester.

Esterification reaction: the role of concentrated sulfuric acid in it: catalyst, absorbent, dehydrator, catalyst is naturally needless to say, esterification reaction is dehydration, concentrated sulfuric acid can play such a role; The esterification reaction is a reversible reaction, and the degree of reversibility is large, and the concentrated sulfuric acid absorbs water, so that the products are reduced, and the balance is positively shifted.

In the reaction of alcohol added to concentrated sulfuric acid for cothermal dehydration, concentrated sulfuric acid is used as a catalyst and dehydrating agent, and the reversibility of this reaction is small, so there is no need for water absorption.