What occurs at the anode of a fuel cell?

At the anode of a fuel cell, oxidation reactions take place. Specifically, hydrogen gas is oxidized, meaning that it loses electrons. This process can be represented by the half-reaction where hydrogen molecules dissociate into protons and electrons. The electrons produced from this oxidation reaction flow through an external circuit to perform electrical work while the protons move through the electrolyte to the cathode.

It's essential to grasp that the anode is the site of oxidation because this foundational concept underpins how electrochemical cells function. In a fuel cell, it's crucial for the anode to efficiently oxidize the fuel (in this case, hydrogen) to generate the necessary electrons that drive the cell's operation. The other options provided relate to processes that either occur at the cathode or are not characteristic of the anode in a fuel cell context.