Catalysis Presentation

Group Name : The Intimidators
Presented by :
Nisha Ahuja
Roshni Kungwani
B. Pharmacy 2 year
Guided By:
MS. PRADNYA GONDANE
M. Pharm (Pharma. chemistry)
Designation: Assistant Professor

WHAT IS CATALYSIS
 Catalysis is the increase in the rate of a chemical reaction
due to the participation of an additional substance called a
catalyst
 With a catalyst, reactions occur faster and with less energy.
 Catalysis are substances which, when added to a reaction,
increase the rate of reaction by providing an alternate
reaction pathway with a lower activation energy (Ea).
 They do this by promoting proper orientation between
reacting particles
 In biochemistry, catalysts are known as enzymes
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CATALYST
PARAMETERS
Activity
The activity of a catalyst depends upon the strength of
chemisorption to a large extent. The reactants must get
absorbed reasonably strongly on to the catalyst to become
active.
Stability
The number of reactions performed by each active site before it
decays or becomes inactive

CATALYST
PARAMETERS
Selectivity
The Selectivity of a catalyst is its ability to direct a
reaction to yield a particular product.
For example
The number of reactions performed by each active site
before it decays or becomes inactive.
CO (g) + 3H2 (g)
Ni CH4(g) + H2O (g)
CO (g) + 3H2 (g) Cu/ZnO-Cr
2
O
3 CH3OH(g)
CO(g) +H2(g) C u HCHO(g)

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

HOMOGENOUS
CATALYST
When the reactants and the catalyst are in the same phase (i.e.
Liquid or gas),the process is said to be homogenous catalysis.
For e.g. - :
C12H22O11 (aq) + H2O(l) H2SO4 C6H12O6(aq) + C6H12O6(aq)
Solution Glucose Fructose
Solution
Advantages
Good contact with reactants.
Disadvantages
• Catalyst needs to be separated after reaction.
• Catalyst recover may be difficult because the temperature for
the distillation can destroy the catalyst.

HETEROGENEOUS
CATALYSIS
The catalytic process in which the reactants and the catalyst are in
different phases is known as heterogeneous catalysis
For e.g. -:
Oxidation of sulphur dioxide into sulphur trioxide in the presence of
Pt.
2SO2(g)
Pt (s)
2SO3(g)
The reactant is in gaseous state while the catalyst in the solid state.
Advantages
There is a 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.

ENZYMATIC CATALYSIS
• Numerous reactions that occur in the bodies of
animals and plants to maintain the life process are
catalyzed by 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.

CHARACTERISTICS OF
ENZYME CATALYSIS
Highly Efficient
One molecule of an enzyme may transform one million reactant molecules per minute
Highly Specific in Nature
Example- Urease enzyme catalyzes the hydrolysis of urea only and not the hydrolysis
of any other amide
Catalysts are highly specific
Highly active at Optimum temperature
The temperature at which the rate of an enzyme catalyzed reaction is maximum is
called Optimum temperature. On either side this temperature, enzyme activity
decreases
Example- Human body temperature(310K) is suitable for enzyme-catalyzed reactions
Highly active at Optimum pH
The rate of an enzyme-catalyzed reaction is maximum at a particular pH called the
Optimum pH

CHARACTERISTICS OF
ENZYME CATALYSIS
 Activity Increases in presence of Activators and Co-enzymes-
 The enzymatic activity increases considerably in the presence of certain other substances
called co-enzymes.
 Example- When a certain non-protein(vitamin) is present along with the enzyme,
catalytic activity is enhanced
 Influence of inhibitors and Poisons-
 Like ordinary catalysts, enzymes are also inhibited by the presence of certain substances
(inhibitors or poisons).
 These substances interact with the active functional groups on the surface of the enzyme
and usually reduce or completely destroy the catalytic activity of the enzymes
 Example- Many of the drugs we use is related to their action as enzyme inhibitors in our
body

MECHANISM OF
ENZYME CATALYSIS
Step 1: Binding of enzymes to substrate to form an
activated complex.
E+S ES≠
Step 2 : Decomposition of the activated complex to form
product.
ES≠
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Gurunank College of Pharmacy
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SOME EXAMPLES OF
ENZYME CATALYSIS
REACTION
1.Oxidation and reduction: Enzymes that carry out these reactions are
called oxidoreductases. For example, alcohol dehydrogenase converts primary
alcohols to aldehydes.
2.Group transfer reactions: These enzymes, called transferees, move functional
groups from one molecule to another. For example, alanine aminotransferase
shuffles the alpha‐amino group between alanine and aspartate:

SOME EXAMPLES OF
ENZYME CATALYSIS
REACTION
3.Hydrolysis: These enzymes, termed hydrolases, break single bonds
by adding the elements of water. For example, phosphatases break the
oxygen‐phosphorus bond of phosphate esters:
4.Formation or removal of a double bond with group transfer. The
functional groups transferred by these lease enzymes include amino
groups, water, and ammonia. For example, decarboxylases remove
CO 2 from alpha‐ or beta‐keto acids:

SOME EXAMPLES OF
ENZYME CATALYSIS
REACTION
5.Isomerization of functional groups: In many biochemical reactions,
the position of a functional group is changed within a molecule, but the
molecule itself contains the same number and kind of atoms that it did in
the beginning. In other words, the substrate and product of the reaction
are isomers. The isomerases (for example, triose phosphate isomerase,
shown following), carry out these rearrangements.

6.Single bond formation by eliminating the elements of water. Hydrolases break
bonds by adding the elements of water; ligases carry out the converse reaction,
removing the elements of water from two functional groups to form a single
bond. Synthetases are a subclass of ligases that use the hydrolysis of ATP to
drive this formation. For example, aminoacyl‐transfer RNA synthetases join
amino acids to their respective transfer RNAs in preparation for protein
synthesis; the action of glycyl‐tRNA synthetase is illustrated in this figure:
SOME EXAMPLES OF
ENZYME CATALYSIS
REACTION

APPLICATION OF
CATALYSIS

ENVIRONMENT
Catalysis impacts the environment by increasing
the efficiency of industrial processes, but catalysis
also plays a direct role in the environment. A
notable example is the catalytic role of chlorine free
radicals in the breakdown of ozone. These radicals
are formed by the action
of ultraviolet radiation on chlorofluorocarbons (CF
Cs).
Cl· + O3 → ClO· + O2
ClO· + O· → Cl· + O2

GREEN CHEMISTRY IS
CATALYSIS
 Pollution control(air and
waste streams; stationary and
mobile)
 Clean oxidation/halogenation
processes using
O2,H2O2(C2H4O, C3H6O)
 Avoiding toxic chemicals in
industry (HF, COCL2,etc.)
 Fuel Cells(H2 generation)

GREEN CHEMISTRY IS
CATALYSIS
catalytic reagents appear to play an impactful role in the
development of greener processes, there are always a couple
points on the flip side of the coin to consider. For instance, a
reaction employing a catalyst may not necessarily be “green”,
since the “greenness” of the catalyst itself should be considered
as well (ie. Is the catalyst itself toxic? Is it environmentally
benign?). In addition, the lifetime of a catalyst matters; a
catalyst can in theory perform a reaction an infinite number of
times, but in practice it loses its effectiveness after a certain
period of time.

CATALYTIC
CONVERTERS
 One Common application
for catalysts is for catalytic
converters.
 Catalytic converters are
found in automobiles.
 Their role is to reduce to
emissions of harmful gases
(CO,VOC’s, NOx)that are
the result of the combustion
of fuel in vehicle engines.

OZONE GAS
DEPLETIONThere 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).

CATALYSIS IN THE
CHEMICAL INDUSTRY
 Hydrogen Industry(Coal, Hydrocarbons)
 Natural gas Processing
 Petroleum Refining
 Petrochemicals (monomers, bulk chemicals)
 Fine Chemicals(pharma, agrochem , fragrance, textile, coating,
surfactants, laundry etc.).
 Environmental Catalysis (Auto exhaust).

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.

FOOD PROCESSING
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 catalysts

Catalysis Presentation

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