I suppose all the aromatic molecules found in petroleum could be modified/given a metallic atom to make the molecules conductive between electrodes
A tremendous amount of energy can be releases from the ignition of ammonium nitrate soaked with petroleum products like diesel. To build a fuel cell that utilizes the ingredients of a fertilizer bomb would be a very dangerous challenge requiring some ingenuity to convert the potential energy in the petroleum into electricity without an explosion whoops - boom.