I know there're two ways in which catalyst works--adsorption and by forming intermediate compounds. Simply, a catalyst stick to the surface of the reactant and increases their chances of collide with each other. That increases the reaction rate because the speed in which a reaction occurs is depends upon the rate in which the molecules collide.

 

Is it because of their electron configuration that they don't react(catalyst)?

Depends on the catalyst really. In acid catalysed esterifications, the acid reacts with the carbonic acid to form an intermediate.

The catalyst actually always "reacts" with the reactants. It forms an intermediate state (a local minima of energy). However during the later steps of the reaction, the intermediate state reacts with another reactant to give you your product and you get your catalyst back. So the catalyst is not consumed in the overall reaction.

out of curiosity, does different chemical reactions require different catalyst?

 

or a catalyst can be used in all types of chemical reactions?

Every reaction will require a different catalyst depending on whats going on.

 

Hydrogenation with hydrogen requires a metal catalyst (normally palladium)

Esterification usually requires an acid

Some biological reactions use catalytic water

Hora2002,

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can you give an example for each of the different chemical reactions you mentioned?

Ex: A (g)+ B (g) ---> AB (s)

Well for the hydrogenation, try looking up Wilkinsons catalyst. That is a ruthenium based homogenous catalysts for reducing alkenes to alkanes.

 

The ester one is an example

 

And certain bacteria in the proteasome use a catalytic water molecule in the degredation of proteins