## 4 Discussion  
This experiment is the first of its kind to explore several pure metals as electrode materials in a fuel cell using hydrogen peroxide as the oxidant and reductant. The experiments show that the metals combinations are capable of generating electrical energy at different levels when used in a single-compartment hydrogen fuel cell model. The results demonstrate consistent electrochemical activity when the novel metals are paired with themselves and other commonly used electrodes (like glassy carbon (GC), Ni, Pt, and Ag). The fabricated rare earth metal electrodes had the most stable activity in the alkaline peroxide electrolyte, as no visible oxidation or corrosion formed. In the Alkaline Electrolyte, any combination of electrodes produced a cell output potential of \(-\)0.2 V to 0.2 V. The most optimal combination was Dy with Ni, Ag, Ta, and Sb. This is followed by glassy carbon, as shown in Table 5. Dy's greater cell output potential may be due to it having a similar electrocatalytic activity to GC, as they both performed well with Er. However, this trend did not continue, as GC performed well with Gd, Ho, and Tb, while Dy had a lower output potential when paired with them. When evaluating results, peak power density is useful for comparing results within similar test conditions, including electrolyte pH, fuel, electrolytic salt concentration, voltammetry sweep range, and sweep rate. As the conditions are kept similar in this experiment, the results can be compared, as shown in Table 9. Ta had the highest electrical power density and alkaline peroxide electrolyte, and Ho had the highest among the rare earth metals. Ta and Sb performed well in the Acidic Electrolyte, delivering similar potential values, with Sb performing the best in an acidic solution with a pH of about 2. It should be noted the quality of the potential values does not correlate with the calculated power density values. Ho, with a larger power density in the alkaline peroxide electrolyte, generated a similar output potential to Er and Tb, despite those having a lower power density than Ho. One possibility for this could be that when Ho is paired with GC in the Alkaline Electrolyte, it produces a similar output potential to Er and Tb, except at a much higher output current. However, this would require further testing to understand. Acidic peroxide electrolytes are more conducive to catalyzing reactions. Hydrogen peroxide is known to be more stable in acidic pH ranges. As mentioned in the introduction, Equations (1) and (2) are the redox reaction of hydrogen peroxide in acidic pH and Equations (3) and (4) is the reaction in alkaline pH. The alkaline pH enters the reaction in \begin{table}
\begin{tabular}{c c c} \hline \hline
**Electrode** & **Peak Power Density—Alkaline** & **Peak Power Density—Acidic** \\  & **Electrolyte (pH 13.3, 0.3 M H\({}_{2}\)O\({}_{2}\))** & **Electrolyte (pH 2.0, 0.3 M H\({}_{2}\)O\({}_{2}\))** \\ \hline Ta & 6998.45 \(\mu\)W/cm\({}^{2}\) @ 0.492 V & 2677.67 \(\mu\)W/cm\({}^{2}\) @ 0.597 V \\ Sb & N/A (electrode corrosion) & 8354.65 \(\mu\)W/cm\({}^{2}\) @ 0.320 V \\ Dy & 33.97 \(\mu\)W/cm\({}^{2}\) @ 0.506 V & N/A (electrode corrosion) \\ Er & 31.39 \(\mu\)W/cm\({}^{2}\) @ 0.503 V & N/A (electrode corrosion) \\ Gd & 113.51 \(\mu\)W/cm\({}^{2}\) @ 0.495 V & N/A (electrode corrosion) \\ Ho & 6308.55 \(\mu\)W/cm\({}^{2}\) @ 0.504 V & N/A (electrode corrosion) \\ Tb & 57.76 \(\mu\)W/cm\({}^{2}\) @ 0.493 V & N/A (electrode corrosion) \\ \hline \hline \end{tabular}
\end{table} 
Table 9: The calculated peak power density values of electrodes at respective electrolyte conditions. its dissociated form. This reduces the stability of the hydrogen peroxide in an alkaline pH. Therefore, the decrease in stability disproportionately increases the likelihood of hydrogen peroxide. It can be theorized that the decrease in the disproportionation rate of the peroxide in an Acidic Electrolyte allows it to be more efficient at generating electrocatalytic reactions in a fuel cell setup.