Page 67 - MODERN ELECTROCHEMISTRY

12 CHAPTER 1

Fig. 1.6. Grove was the first to obtain
electric power directly from a chemi-
cal reaction.

electrode–electrolyte interfaces and are each susceptible to electrical control as far as
rate (electron flow) is possible.
If electrical energy provokes and controls chemical reactions, chemical reactions
working in the other direction can presumably give rise to a flow of electricity. Thus,
two reactant substances may be allowed to undergo spontaneous electron transfer at
the separated (electrode) sites, which is characteristic of the electrochemical way of
bringing about chemical reactions, and then the electrons transferred in the two
reactions at the two interfaces will surge spontaneously through an electrical load, for
example, the circuit of an electric motor (Fig. 1.6). In this reverse process, also, there
is a unique aspect when one compares it with the production of available energy from
thermally induced chemical reactions. It can be shown (see Chapter 13 in vol 2) that
the fraction of the total energy of the chemical reaction that can be converted to
mechanical energy is intrinsically much greater in the electrical than in the chemical
way of producing energy. This is a useful property when one considers the economics
of running a transportation system by means of a fuel cell–electric motor combination
rather than by means of the energy produced in the combustion of gasoline.

1.5. THE RELATION OF ELECTROCHEMISTRY TO OTHER SCIENCES

1.5.1. Some Diagrammatic Presentations

Let us look at Fig. 1.7 to see something of the parentage of conventional
electrochemistry, in both the ionic and electrodic aspects. We could also look at these
relations in a different way and make the central thought a charge transfer at interfaces,
while stressing the interdisciplinary character of the fields involved in studying it. Such