## 4 Discussion
This could be due to GC's natural defects, where the carbon oxidation can occur at microscopic fault areas through the electrochemical reactions with the dissolved oxygen in the water and hydrogen peroxide in both the anodic and cathodic sweeps. It is also possible the GC has low anodic catalytic activity with hydrogen peroxide, where Ta and Sb would be the main source of the output potentials shown in Table 5.  
Looking at Ho in the oxidative region at the early anodic sweep potentials, it had one of the strongest catalytic rises in its voltammogram. This rise lasted well beyond 0.5 V, after which it started to plateau. The plateau could be a sign of a need for higher mass transport of hydrogen peroxide to this electrode; however, a concentration of 0.3 M of hydrogen peroxide should be a sufficient amount of hydrogen peroxide molecules near the surface of the Ho electrode. Although Ho had a strong catalytic voltammogram, it cannot perform substantially better than the other novel electrodes in generating cell output potentials when paired with the glassy carbon electrode. The voltammogram of Ho had one of the highest current densities during the anodic voltage sweep, and therefore, it is possible that though it produces a similar output potential as Er, Gd, and Tb, a fuel cell of Ho and GC in alkaline peroxide could produce a higher electric current. Tb's voltammogram showed no catalytic activity in the anodic or cathodic directions when scanned in the range of \(-0.5\) to 0.5 V. This is surprising, as Tb can generate a considerable cell output potential when paired with the GC electrode in an Alkaline Electrolyte. Given the inert catalytic activity, the measured potential may be a result of the paired electrodes catalytic activity. An electrode pairing that uses Tb would likely create a measurable amount of potential with low amounts of current. Sb demonstrated a similar electrochemical activity to Tb in alkaline peroxide. The Sb electrode would generate a large output potential even though the electrode itself formed surface corrosion when used in a cyclic voltammetry experiment. This corrosion could be the result of a low current and a higher output potential. Therefore, forcefully sweeping the potentials in a cyclic voltammetry leads to the observed surface corrosion layer. Ta is a strong electrode in alkaline peroxide. Compared to any other novel electrode tested, it has the greatest catalytic peak rise in the oxidative scan direction. The catalytic peak also increases by about 3 mA/cm\({}^{2}\) at 0.5 V when hydrogen peroxide is included. In the electrolyte without hydrogen peroxide, it is composed of water and sodium hydroxide. It is unknown what is being oxidized during the Ta electrodes cyclic voltammetry, as it would require a much higher potential for the hydroxide ion to oxidize in alkaline pH to form water. It also takes a higher potential than 0.5 V to generate tantalum hydroxide or tantalum oxide. Ta was also one of the only electrodes that was compatible in the alkaline, neutral, and acidic pH ranges, keeping its polished surface after any electrochemical tests. Ta's different catalytic activity in the presence of hydrogen peroxide in acidic, alkaline, and neutral pH electrolytes can be observed by overlapping its voltammograms in Figure 10. In the three pH electrolytes, Ta has similar onset potentials in the anodic potential sweep direction. The open circuit potentials in the various electrolytes decrease in order of neutral (222.7 mV), alkaline (200.7 mV), and acidic (173.9 mV). The slope of the catalytic voltammogram peaks in the anodic sweep decreases in the order of alkaline, acidic, and neutral. This demonstrates that a Ta electrode in an alkaline peroxide electrolyte will lead to a lower output potential and higher current compared to using an acidic peroxide electrolyte. The voltammograms of ceSb in the different pH electrolytes is shown in Figure 11. Sb has the most catalytic activity in the neutral pH.