1. Introduction

This chapter shows the hydrogen production from ethanol-steam reformation and from photocatalysis and photoelectrochemical processes and the use of the hydrogen in a proton exchange membrane fuel cell (PEMFC) to convert chemical energy into electrical energy. The photocatalysis and photoelectrochemical processes use the solar energy for direct conversion of solar energy into renewable hydrogen fuel; moreover, solar energy is the unique renewable source that can fulfill the world's needs for the future to produce hydrogen fuel and generate the electricity. Hydrogen production can feed a PEMFC which converts chemical energy into electric energy by an electrochemical reaction. H2 is oxidized at the anode and O2 (often in the form of air) is reduced at the cathode, which results in electrical work. This system presents the advantage that it can be used in remote place to convert electrical energy without ambient degradation.
