What is the temperature needed to separate hydrogen from water?

Answer 1

Thermal decomposition, also called thermolysis, is defined as a chemical reaction whereby a chemical substance breaks up into at least two chemical substances when heated. At elevated temperatures water molecules split into their atomic components hydrogen and oxygen. For example at 2200 °C about three percent of all H2O molecules are dissociated into various combinations of hydrogen and oxygen atoms, mostly H, H2, O, O2, and OH. Other reaction products like H2O2 or HO2 remain minor. At the very high temperature of 3000 °C more than half of the water molecules are decomposed, but at ambient temperatures only one molecule in 100 trillion dissociates by the effect of heat. However, catalysts can accelerate the dissociation of the water molecules at lower temperatures.

Answer 2

The process of separating hydrogen from water, known as water electrolysis, typically requires a temperature of around 25-80 degrees Celsius to be efficient. Higher temperatures can increase the rate of the reaction, but also lead to higher energy consumption.