The electrochemical reaction on the anode side of a fuel cell can be expressed as hydrogen split into hydrogen protons and electrons. I'm doing some research about the electrochemical reaction in a fuel cell. Is the anode side electrochemical reaction a heat release process or a heat absorption process?
The answer lies in your question itself. The left hand side of the anode half-cell equation contains H-H, whereas the right hand side contains isolated H⁺ ions.
What do you have to do in order to break the H-H bond to isolate them? Obviously you must supply them with heat energy equal to or greater than the bond enthalpy of the H-H bond. Hence, the anode process is a heat absorption process.