Here's a breakdown:
* Platinum's role: Platinum acts as a catalyst. Catalysts speed up chemical reactions without being consumed themselves. In this case, platinum provides a surface where sulfur dioxide and oxygen molecules can interact more easily, lowering the activation energy needed for the reaction.
* The reaction: Sulfur dioxide (SO₂) reacts with oxygen (O₂) in the presence of platinum to form sulfur trioxide (SO₃).
* The equation: 2 SO₂ (g) + O₂ (g) → 2 SO₃ (g)
* The process: This reaction is the key step in the Contact process, a vital industrial process for producing sulfuric acid (H₂SO₄).
Here's how the Contact process works:
1. Sulfur is burned in air to produce sulfur dioxide (SO₂).
2. Sulfur dioxide is then mixed with air (containing oxygen) and passed over a platinum catalyst at a high temperature (around 400-450°C). This is where the catalytic oxidation happens.
3. Sulfur trioxide (SO₃) is absorbed in concentrated sulfuric acid to form oleum (H₂S₂O₇).
4. Oleum is then diluted with water to produce concentrated sulfuric acid (H₂SO₄).
Why is this important?
Sulfuric acid is a highly important industrial chemical used in a wide range of applications, including:
* Fertilizer production
* Metal processing
* Battery production
* Dye and pigment manufacturing
* Paper production
Important Note:
The reaction of sulfur dioxide with oxygen in the presence of platinum is highly exothermic, meaning it releases a lot of heat. Careful temperature control is essential to prevent the catalyst from becoming too hot and losing its effectiveness.
