The
water-gas shift reaction (WGSR) describes the reaction of
carbon monoxide and
water vapor to form
carbon dioxide and
hydrogen (the mixture of carbon monoxide and hydrogen is known as
water gas):
- CO + H2O
CO2 + H2
The water gas shift reaction was discovered by Italian physicist
Felice Fontana in 1780. It was not until much later that the industrial value of this reaction was realized. Before the early 20th century, hydrogen was obtained by reacting steam under high pressure with iron to produce iron, iron oxide and hydrogen. With the development of industrial processes that required hydrogen, such as the
Haber–Bosch ammonia synthesis, the demand for a less expensive and more efficient method of hydrogen production was needed. As a resolution to this problem, the WGSR was combined with the gasification of coal to produce a pure hydrogen product. As the idea of
hydrogen economy gains popularity, the focus on hydrogen as a replacement fuel source for hydrocarbons is increasing.