**Introduction**

In the given options, the lead chamber process does not use a catalyst. The other three processes, namely Haber's process, Deacon's process, and Solvay process, require the use of catalysts to facilitate the desired chemical reactions.

**Lead Chamber Process**

The lead chamber process is a method used for the industrial production of sulfuric acid. It involves the oxidation of sulfur dioxide (SO2) to sulfur trioxide (SO3), which is then further reacted with water to form sulfuric acid (H2SO4).

In the lead chamber process, a catalyst is not used to facilitate the conversion of SO2 to SO3. Instead, the reaction is carried out by mixing SO2 and nitrogen dioxide (NO2) gases in the presence of excess oxygen. The reaction occurs at elevated temperatures and is driven by the presence of moisture in the reaction mixture. The overall reaction can be represented as follows:

2SO2 + 2NO2 + O2 + 2H2O -> 2H2SO4 + N2

**Haber's Process**

Haber's process is used for the synthesis of ammonia (NH3) from nitrogen gas (N2) and hydrogen gas (H2). This process is essential for the production of fertilizers and various other chemical compounds. In Haber's process, an iron catalyst is used to increase the reaction rate and improve the yield of ammonia. The reaction occurs at high pressures and moderate temperatures.

**Deacon's Process**

Deacon's process involves the oxidation of hydrogen chloride (HCl) gas to produce chlorine (Cl2) gas. This process is used for the commercial production of chlorine, which has various industrial applications. In Deacon's process, a catalyst such as cupric chloride (CuCl2) is used to enhance the reaction rate. The reaction occurs at elevated temperatures and requires the presence of excess oxygen.

**Solvay Process**

The Solvay process is utilized for the production of sodium carbonate (Na2CO3), commonly known as soda ash. This process involves the reaction between sodium chloride (NaCl) and calcium carbonate (CaCO3) in the presence of ammonia (NH3). A catalyst, typically in the form of a small amount of ammonia, is used to initiate the reaction and increase its efficiency. The Solvay process occurs at relatively low temperatures and atmospheric pressure.

**Conclusion**

In summary, the lead chamber process is the only option among the given processes that does not require the use of a catalyst. Haber's process, Deacon's process, and Solvay process all utilize catalysts to enhance the reaction rates, improve yields, and increase the efficiency of the respective chemical reactions.

I thought C?