> Introduction
- A substance while is increase or decrease the rate of reaction whithout taken in part any reaction is known as catalyst
- The mechanism of catalysis the freeenergy of activation is dowered by the presence of catalyst
- The catalst is promoting the reverde reaction for example. platinum
- For the platinum is effective catalyst for the oxidation of Co² & Co³ they also found speedly decomposition of So³ in to So² & O²
- The rate of reaction decrese by the presence of catalyst is called negative catalyst
- For Example Nitric Oxide, Iodines
2.) Types Of Catalytic Reaction
- There are two types of catalytic reation...
1) Homogeneous Catalyst
2) Heterogeneous Catalyst
- let us consider that a non catalytic biomolecular reaction proceed as follows..
A) Homogeneous Catalyst
- When the catalyst & raection substances are in the same phase is called homogeneous catalyst.
- Homogeneous catalyst reaction may be gaseous & liquid.
- Such types of reaction are used in Industry in batch or continus tank reaction
- For Examples
1) CH³COOCH³ + H²O -----> CH³COOH
Methyl acetate Acetic acid
+ CH³OH
2) So²+ O² ---No(g)--> So³g
3) 2Co + O² ---NO(g)--> 2Co²
B) Heterogeneous Catalysts
- When the catalysty and reaction substance are in the different phase is called heterogeneous catalyst
- The combination of H² & O² from water vapour is heterogeneous catalyst.
- The platinum is separation phase the reaction mixture.
- For Example
1) So² + O² ---V²O5--> So³(g)
2) N² + 3H² ----Fe---> 2NH³
3) Co + 2H² ---Cu,Zn,--> CH³OH
4) water vapour ---Pt--> H² + O²
3.) Propetries Of Solid Catalyst : Contact Masses.
- The most important requirement of a good Industrial catalyst are
I) It must be active in agiven traction
II) It should be stable to the action of contact poision
III) It should be cheap & have a high
mechanical strength
IV) It Should be heat resistance
V) It should be definite thermal conductivity.
> Factor Affecting Catalysis
1) Catalyst Activity
- The pressure also affecte the product yield of a catalyst process in according with lechatelier's principal
- That is why an increase or a high pressure is widely used in many industrial catalyst processes
- For example in the synthesis of ammonia & methanol the pressure become the decisive factor when the catalyst activity & the product yield not high
2) Temperature
- The effect of temperature is not always clearly pronounce for eg. when the temperature is raised above a creation limit in the catalyst reaction of ammonia oxidation methenol & ethanol synthesis harmful side reaction being to take place.
- For process including several reaction are especially if they have oppsite sing of their heat effect overall reaction is endothermic but the laws of endothermic processes
3) Concentration Reactants
-The concentration of the reactants affects the rate of catalytic reaction in the same way as the rate of ordinary chemical reaction
-For eg. when a process is highly exothermic & it is difficult to remove all the step in the process are essentially the same as for the usal precipitation.
- catalyst contaning silica & alumina are essentially suitable for preparations by gel formation because thair precipitation are of collidal nature.
- In some cases a prous material can be obtainec by mixing the components with water milling to the desired effect gain size drying & calcling
- A mixed magnesium & calcium oxide catalyst can thus be prepared. the carbonates are milled wet in a ball machine,extruded,dried & then reduced by a heating in an oven.
- This is important when cosily metals such as the platinum,nikal, & silver are used as catalyst.
- A substance while is increase or decrease the rate of reaction whithout taken in part any reaction is known as catalyst
- The mechanism of catalysis the freeenergy of activation is dowered by the presence of catalyst
- The catalst is promoting the reverde reaction for example. platinum
- For the platinum is effective catalyst for the oxidation of Co² & Co³ they also found speedly decomposition of So³ in to So² & O²
- The rate of reaction decrese by the presence of catalyst is called negative catalyst
- For Example Nitric Oxide, Iodines
2.) Types Of Catalytic Reaction
- There are two types of catalytic reation...
1) Homogeneous Catalyst
2) Heterogeneous Catalyst
- let us consider that a non catalytic biomolecular reaction proceed as follows..
A) Homogeneous Catalyst
- When the catalyst & raection substances are in the same phase is called homogeneous catalyst.
- Homogeneous catalyst reaction may be gaseous & liquid.
- Such types of reaction are used in Industry in batch or continus tank reaction
- For Examples
1) CH³COOCH³ + H²O -----> CH³COOH
Methyl acetate Acetic acid
+ CH³OH
2) So²+ O² ---No(g)--> So³g
3) 2Co + O² ---NO(g)--> 2Co²
B) Heterogeneous Catalysts
- When the catalysty and reaction substance are in the different phase is called heterogeneous catalyst
- The combination of H² & O² from water vapour is heterogeneous catalyst.
- The platinum is separation phase the reaction mixture.
- For Example
1) So² + O² ---V²O5--> So³(g)
2) N² + 3H² ----Fe---> 2NH³
3) Co + 2H² ---Cu,Zn,--> CH³OH
4) water vapour ---Pt--> H² + O²
3.) Propetries Of Solid Catalyst : Contact Masses.
- The most important requirement of a good Industrial catalyst are
I) It must be active in agiven traction
II) It should be stable to the action of contact poision
III) It should be cheap & have a high
mechanical strength
IV) It Should be heat resistance
V) It should be definite thermal conductivity.
> Factor Affecting Catalysis
1) Catalyst Activity
- The pressure also affecte the product yield of a catalyst process in according with lechatelier's principal
- That is why an increase or a high pressure is widely used in many industrial catalyst processes
- For example in the synthesis of ammonia & methanol the pressure become the decisive factor when the catalyst activity & the product yield not high
2) Temperature
- The effect of temperature is not always clearly pronounce for eg. when the temperature is raised above a creation limit in the catalyst reaction of ammonia oxidation methenol & ethanol synthesis harmful side reaction being to take place.
- For process including several reaction are especially if they have oppsite sing of their heat effect overall reaction is endothermic but the laws of endothermic processes
3) Concentration Reactants
-The concentration of the reactants affects the rate of catalytic reaction in the same way as the rate of ordinary chemical reaction
-For eg. when a process is highly exothermic & it is difficult to remove all the step in the process are essentially the same as for the usal precipitation.
- catalyst contaning silica & alumina are essentially suitable for preparations by gel formation because thair precipitation are of collidal nature.
4) Intensity Of Mixture
- In some cases a prous material can be obtainec by mixing the components with water milling to the desired effect gain size drying & calcling
- A mixed magnesium & calcium oxide catalyst can thus be prepared. the carbonates are milled wet in a ball machine,extruded,dried & then reduced by a heating in an oven.
- This is important when cosily metals such as the platinum,nikal, & silver are used as catalyst.
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