By -: LovnishThakur(IBT-1stSem)
Enrollment No.-: ASU2014010100099
Course -: Chemistry for biologist (102)
www.ecopolychem.com

Catalysisistheincreaseintherateofachemicalreactionduetotheparticipationofanadditionalsubstancecalledacatalyst.
With a catalyst, reactions occur faster and with less energy

Catalystsaresubstanceswhich,whenaddedtoareaction,increasetherateofreactionbyprovidinganalternatereactionpathwaywithaloweractivationenergy(Ea).
They do this by promoting proper orientation between reacting particles.
In biochemistry, catalysts are known as enzymes.

Catalyst Cycle
www.catalysis-ed.org.uk

commons.wikimedia.or

Catalyst Parameters

Homogeneous Catalysis
The catalyst and reactants are in the same phase, usually liquid.
Heterogeneous catalysis
Catalyst and reactants are in different phases.
Enzymatic Catalysis
Catalyst is an enzyme (macromolecules made of amino acids).

When the reactants and the catalyst are in the same phase (i.e., liquid or gas), the process is said to be homogeneous catalysis.
For e.g-:
Advantages

Good contact with reactants .
Disadvantageswww.ncert.nic.in/NCERTS/l/lech105.pdf

Catalysis needs to be separated after reaction

Catalyst recovery may be difficult because the temperature for the distillation can destroy the catalyst
www.ncert.nic.in/NCERTS/l/lech105.pdf

The catalytic process in which the reactants and the catalyst are in different phases is known as heterogeneous catalysis.
For e.g-:
Advantages

There is little difficulty in separating and recycling the catalyst.
Disadvantages

There is a lower effective
concentration of catalyst
since the reaction occurs
only on the exposed active surface.(www.knockhardy.org.uk)

Adsorption Theory of HeterogeneousCatalysis
www.ncert.nic.in/NCERTS/l/lech105.pdf

Numerous reactions that occur in the bodies of animals and plants to maintain the life process are catalysedby enzymes. The enzymes are, thus, termed as biochemical catalysts and the phenomenon is known as biochemical catalysis.
Enzymes are complex nitrogenous organic compounds which are produced by living plants and animals. They are actually protein molecules of high molecular mass

(i) Most highly efficient: One molecule of an enzyme may transform
one million molecules of the reactant per minute.
(ii) Highly specific nature: Each enzyme is specific for a given reaction.
For example, the enzyme ureasecatalyses the hydrolysis of urea only.
(iii) Highly active under optimum temperature
(iv) Highly active under optimum pH

Mechanism of enzyme catalysis
www.ncert.nic.in/NCERTS/l/lech105.pdf

Catalysis reaction by sucrase
www.etrailer.com

Some example of enzyme catalysis reaction
www.ncert.nic.in/NCERTS/l/lech105.pdf

APPLICATION OF CATALYSIS

Catalysis impacts the environment by increasing the efficiency of industrial processes, but catalysis also plays a direct role in the environment

Green Chemistry is Catalysis

Pollution control(air and waste streams; stationary and mobile)

Clean oxidation/
halogenationprocesses using O2,H2O2(C2H4O, C3H6O)

Avoiding toxic chemicals in industry
( HF,COCl2etc.)

Fuel cells( H2 generation)
commons.wikimedia.or

Catalytic Converters

Onecommonapplicationforcatalystsisforcatalyticconverters.

Catalyticconvertersarefoundinautomobiles.

Theirroleistoreducetoemissionsofharmfulgases(CO,VOC’s,NOx) thataretheresultofthecombustionoffuelinvehicleengines.
ysis-ed.org.uk

Ozone gas depletion
There is catalytic role of chlorine free radicals in
the breakdown of ozone. These radicals are formed by the action
of ultraviolet radiation on chlorofluorocarbons (CFCs).
www.okiu.ac.jp

www.okiu.ac.jp


Hydrogen Industry
(coal, hydrogenations etc).

Natural gas processing .

Petroleum refining . www.ecopolychem.com

Petrochemicals(monomers, bulk chemicals).

Fine Chemical(pharma, agrochem, fragrance, textile, coating, surfactants, laundry etc).

Environmental Catalysis(autoexhaust).

Fine chemicals

Many fine chemicals are prepared via catalysis; methods include those of heavy industry as well as more

specialized processes that would be prohibitively expensive on a large scale.
www.essentialchemicalindustry.org

www.ncert.nic.in/NCERTS/l/lech105.pdf

shape-selective catalysis
blogs.mcgill.ca blogs.mcgill.ca

The reaction that depends upon the pore structure of the catalyst & the size of the reactant & product molecules is called shape-selective catalysis.

Zeolitesis used as catalysts in petrochemical industries for cracking of hydrocarbons and isomerisation.

An important zeolitecatalyst used in the petroleum industry is ZSM-5.

It converts alcohols directly into gasoline (petrol) by dehydrating them to give a mixture of hydrocarbons.
blogs.mcgill.ca
blogs.mcgill.ca

Energy processing

Petroleum refining makes intensive use of catalysis for alkylation , catalytic cracking (breaking long-chain

hydrocarbons into smaller pieces) , naphtha reforming and steam reforming (conversion

of hydrocarbons into synthesis gas).

Fuel cells depend on catalysts for both the anodic and cathodic reactions.

Catalytic heaters generate flameless heat from a supply fuel

One of the most obvious applications of catalysis is the hydrogenation (reaction with hydrogen gas) of
fats using nickel catalyst to produce margarine .
Many other foodstuffs are prepared via bio catalysis

References

www.etrailer.com

blogs.rsc.org

www.catalysis-ed.org.uk

commons.wikimedia.org

www.ncert.nic.in/NCERT/1/lech105.pdf

www.knockhardy.org.uk

Blog.mcgill.org.uk

Ysis-ed.org.uk

www.ecopolychem.com

THANK YOU