Homogeneous catalysis takes place when the catalyst and the other reactants are all dissolved in the same solution. Heterogeneous catalysis typically involves the use of a catalyst that is insoluble, or perhaps only weakly soluble, in the solution in which the reaction takes place. Thus, in heterogeneous catalysis, the catalyst and solution may form a suspension, or the catalyst may simply be a solid that is placed in the solution.
- These types of catalysts usually are common in either liquid phase or gas phase
- Operative temperature for homogeneous catalysis is generally low except only when under high pressure
- The heat transfer in homogeneous catalysis is very high as all the molecules of reactants and catalysts are in same phase
- Recycling methods are not very cost effective as it’s a long drawn process and as it’s a difficult treatment method for spent catalysts
- Modification of homogenous catalysts is very easy as it depends upon the tuning of electronic and steric properties on metal
- Reaction mechanism easier to find as varied techniques are available
- Heterogeneous catalysis are found in liquid phase, gas phase and solid phase.
- Operative temperature for heterogeneous catalysis is harsh as compared to homogeneous process.
- The heat transfer is relatively low as compared to homogeneous catalysis as the reactant molecules and catalysts are in different phase.
- These catalysts although require reactivating treatment process but still quite cost effective.
- The modification of heterogeneous catalysts is relatively difficult as the controlling methods of particle site as well as the active size at molecular level is really difficult.
- Reaction mechanism is difficult to fins as the techniques utilized as the product is scrutinized and not the catalysts.