Heck, Ei-ichi Negishi and Akira Suzuki for their work on “palladium-catalyzed cross couplings in organic synthesis” which in itself is evidence strong enough to validate the significance of catalysis in the fields of modern science, and particularly in industrial processes. Around 9 billion US Dollars defines the volume of the recent market for catalysts in the Global markets. (Dautzenberg, 2002).
‘Catalysis’ is defined as a phenomenon and ‘catalyst’ is the substance which is responsible for that phenomenon. A Catalyst is a substance which can usually rev up the rate of a chemical reaction but remains unaltered itself (physically and chemically) after the reaction. Sometimes particular substances can also slow down the rate of a chemical reaction. Such type of substances are known as inhibitors (Encyclopædia Britannica, 2011).
According to the involvement in the phases, i.e., state of aggregation, catalysts are divided into three broad categories- (i) homogeneous catalyst (ii) heterogeneous catalyst and (iii) biocatalyst [Cavani &Feruccio, 1997. Hagen, 2006]. As the name suggests, homogeneous catalyst implies to the situation where the substrate and the catalyst are in the similar phase (gas or liquid). A very common example of a homogeneous catalysis is the conversion of carbon monoxide to carbon- di-oxide catalyzed by nitric oxide where both the substrate and catalyst are in gaseous phase. The fundamental advantages of homogeneous catalysis are that this type of catalysis is atom economic in respect to the other catalysis processes and additionally has higher selectivity in producing the desired product for its milder reaction condition. However, there are disadvantages associated with homogeneous catalysis as well. The problematic regarding homogeneous catalysis is the work up procedure of the reaction.