Question

What is a homogeneous catalyst? What are the advantages/disadvantages of it over heterogeneous catalysts?

Answer 1

Catalysis is the addition of a catalyst to a chemical reaction to speed up the pace of the reaction. Catalysts are not consumed and remain unaltered after the reaction. Small quantities of catalyst are generally sufficient if the reaction is fast and the catalyst recycles quickly; mixing, surface area, and temperature are all key variables in reaction rate. Catalysts often react with one or more reactants to produce intermediates, which then provide the ultimate reaction product, renewing the catalyst in the process.

Complete answer:
In chemistry, homogeneous catalysis is the use of a soluble catalyst to catalyse reactions in a solution. Homogeneous catalysis is a term that describes reactions in which the catalyst is in the same phase as the reactants, usually in solution. Heterogeneous catalysis, on the other hand, refers to processes in which the catalysts and substrate are in different phases, generally solid-gas and liquid-liquid, respectively. The phrase is almost exclusively used to describe solutions and refers to organometallic catalysis. Homogeneous catalysis is a well-established technique that is continuously improving. The manufacture of acetic acid is an example of a prominent application. Homogeneous catalysts are things like enzymes.
Advantages-
Homogeneous catalysts are very selective in their production of the intended product.
When a reaction is exothermic, a lot of heat is released. It is simpler to release heat from a solution (as with a homogeneous catalyst) than it is to adsorb reaction participants onto a heterogeneous catalyst, which is often an insoluble solid in solution.
Because the homogeneous catalyst is already in solution, reactants may quickly reach it. This encourages a high level of catalytic activity.
Species in solution are simpler to describe (using different spectroscopic methods, for example) than those adsorbed on a solid surface.
Disadvantages-
If a catalyst capable of dissolving in solution is to be recycled for reuse, it will need to be isolated afterwards (as per the principles of green chemistry).
Even while high temperatures typically encourage quicker reactions, the homogeneous catalyst may have difficulties at high temperatures since we don't want our solution (which contains this catalyst) and any volatile reactants to evaporate.
It might be difficult to separate homogeneous catalysts from products. The catalyst is not removed from the product in some situations involving high activity catalysts. Organic compounds that are sufficiently volatile can be separated by distillation in other instances.

Note:
Heterogeneous catalysis is a kind of chemistry in which the phase of the catalysts differs from that of the reactants or products. In contrast, homogeneous catalysis occurs when the reactants, products, and catalyst are all present in the same phase. Phase distinguishes between solid, liquid, and gas components, as well as immiscible mixes (e.g., oil and water) and any other location where an interface exists.
Solid phase catalysts and gas phase reactants are commonly used in heterogeneous catalysis. At the catalyst surface, a cycle of molecule adsorption, reaction, and desorption is taking place. The rate (kinetics) of a process is influenced by thermodynamics, mass transfer, and heat transmission.