High Voltage and Ozone: Process Overview

[c_d]

Hi Group,

I'm interested in how and why ozone is produced by high voltage discharges. I was hoping that if I give my impression of how the process works, people could correct any mistakes I've made. Here's how I think the process works:

1) Let's pretend a large high voltage arc is generated from a tip of a piece of wire. The arc is quite long and shoots up in the air.

2) The arc is a result of electrons flowing up the wire and then repelling each other. This causes the electrons to fly out from the tip of the wire.

3) As the electrons fly through the air they bond with oxygen molecules (O2). The oxygen molecule now has more electrons than protons. As a result, one of the oxygen atoms in the O2 molecule seperates. This now leaves 2 individual oxygen atoms.

4) The individual oxygen atoms bond with a new oxygen molecule which creates an ozone molecule (O3).

Is my impression of how it works correct?

Another question I have is, in step 3 the electron from the arc bonds with an oxygen molecule. Then the oxygen atoms seperate. What happens to the original electron that caused the seperation? Surely there now exists an oxygen atom which has an extra electron.

Thanks in advance for any help .

 

[DrMark]

Ozone formation from arcs is a result of the ultraviolet radiation that the arc emits. It is a photochemical reaction, not an electrochemical reaction. simply put:

O2 + hv -> 2 O*
O* + O2 -> O3

Hope that helps.

 

[charng]

Hello there,

Your understanding of the process is mostly correct. However, I would like to clarify a few points:

1) The high voltage arc is not generated from the tip of the wire. It is generated from the air surrounding the tip of the wire. The electrons are accelerated by the high voltage and collide with oxygen molecules in the air, creating ozone.

2) The electrons do not bond with oxygen molecules. They collide with them, causing them to split into individual oxygen atoms.

3) The individual oxygen atoms do not bond with a new oxygen molecule. They simply combine with another oxygen atom to form an ozone molecule.

In step 3, the original electron that caused the separation is still present in the system. It is now part of the ozone molecule. The extra electron you mentioned is actually shared between the two oxygen atoms in the ozone molecule.

I hope this helps clarify the process for you. Let me know if you have any further questions.