INTRODUCTION TO WATER ELECTROLYSIS
What is Electrolysis?
Before looking at water, hydrogen or different
electrolyser technologies, first understand
the basic idea behind electrolysis.
💭 Imagine a chemical substance...
Imagine that we have a chemical substance,
AB, and we want to split it apart
into two products, A and B.
However, the desired splitting reaction needs an external supply of energy for it to be driven in that direction (here, by "in that direction", we mean as the reaction has been written, normally from left to right).
What if we supply that energy using electricity?
However, the desired splitting reaction needs an external supply of energy for it to be driven in that direction (here, by "in that direction", we mean as the reaction has been written, normally from left to right).
What if we supply that energy using electricity?
🔍 Breaking down the word: Electrolysis
A useful way to remember the basic idea of
electrolysis is to break the word into two parts:
ELECTRO
electricity / electrical energy
+
LYSIS
splitting / breaking apart
=
ELECTROLYSIS
electrically driven splitting
Electro reminds us of electricity or
electrical energy, while lysis means
splitting or breaking apart.
We can therefore use this as a simple way of remembering the central idea:
In the simple example below, electrical energy will be supplied to drive the splitting of:
We can therefore use this as a simple way of remembering the central idea:
ELECTRO + LYSIS
→
Electrical Energy + Splitting
In the simple example below, electrical energy will be supplied to drive the splitting of:
AB → A + B
Chemical system before electrical energy is supplied
We want to split AB into A and B. Watch what happens
when electrical energy is supplied.
The desired splitting of AB into A and B is
not being driven yet.
Supply electrical energy below (click the orange button shown below).
🔑 The important idea
Electricity is not a chemical reactant
in the same way as substance AB.
It is the energy input used to drive the electrochemical reaction.
Our simple example was:
It is the energy input used to drive the electrochemical reaction.
Our simple example was:
AB + Electrical Energy → A + B
Later, when we consider
water electrolysis, the chemical
substance being transformed will be water.
🎯 Quick Check
One question before moving on.
✓ Block 1 Takeaway
The word can be remembered as:
Electrolysis is the use of electrical energy to drive a chemical reaction.
In our simple example:
Next, we can apply this idea specifically to water.
ELECTRO + LYSIS
electrical energy + splitting
Electrolysis is the use of electrical energy to drive a chemical reaction.
In our simple example:
AB + Electrical Energy → A + B
That is the foundation.
Next, we can apply this idea specifically to water.