## 1 Introduction
\begin{table}
\begin{tabular}{c c c c c c} \hline \hline
**Publication** & \multirow{2}{*}{**Electrodes**} & **Alkaline** & **OCP or** & **PPD** & **Reference** \\
**Year** & & **Electrolyte pH** & **OP (Volts)** & **(\(\mu\)W/cm\({}^{2}\))** & **Reference** \\ \hline
2020 & CNT/VitB\({}_{12}\) & 7.4 & 0.233 & 53.8 & [5] \\ \hline
2020 & rGo/PAA/CoPc vs. [CNT/PEI]/hemin & 7.4 & 0.26 & 72.1 & [6] \\ \hline
2021 & PEI-rGO/CoPc/CoPc vs. [CNT/PEI]/hemin & 7.4 & 0.317 & 105.2 & [7] \\ \hline
2021 & \({}^{\star}\)W-BiVO\({}_{4}\)/V\({}_{2}\)O\({}_{5}\) vs. Cu\({}_{2}\)O/CuO & 8 & 0.41 & 840 & [8]\({}^{\star}\) \\ \hline
**Publication** & \multirow{2}{*}{**Electrodes**} & **Acidic** & **OCP or** & **PPD** & **Reference** \\
**Year** & & **Electrolyte pH** & **OP (Volts)** & **(\(\mu\)W/cm\({}^{2}\))** & **Reference** \\ \hline
2020 & Fe\({}_{\rm{N}}\) vs. Ni mesh & 0.1 M HCl (1.0) & 0.58 & 760 & [9] \\ \hline
2020 & CePC vs. Ni mesh & 0.1 M HCl (1.0) & 0.57 & 400 & [9] \\ \hline
2020 & FePC vs. Ni mesh & 0.1 M HCl (1.0) & 0.56 & 3410 & [9] \\ \hline
2020 & CoPc vs. Ni mesh & 0.1 M HCl (1.0) & 0.47 & 390 & [9] \\ \hline
2020 & CuHCFe\({}^{\rm{III}}\) vs. Ni grid & 0.1 M HCl (1.0) & 0.72 & 8300 & [10] \\ \hline
2024 & ATO/FTO vs. Ni foam & 1.0 & 0.82 & 320 & [11] \\ \hline
2024 & Ag/BiVO\({}_{4}\) vs. Fe\({}^{\rm{III}}\)Pc & 1.0 & 0.61 & 2030 & [12] \\ \hline
2025 & Carbon Fiber cloth vs. Graphite rod with surfactants & 1.0 & 0.61 & 50.6 & [13] \\ \hline \hline \end{tabular} \({}^{\star}\) The catalytic function of the fuel cell is photo-assisted.  
\end{table} 
Table 1: A summary of published single-compartment hydrogen peroxide fuel cell investigations, separated by Alkaline vs. Acidic electrolytes. PPD is peak power density, OCP is open circuit potential, and OP is cell output potential. When the corresponding electrode is underlined, the values in the “OCP or OP” column are for OCP. This paper uses different electrolyte pH values to investigate the use of seven pure elemental metals for the first time as potential electrocatalytic electrodes in a single-compartment hydrogen peroxide fuel cell. This study investigates the following rare earth metals: pure dysprosium (Dy), erbium (Er), gadolinium (Gd), holmium (Ho), terbium (Tb), antimony (Sb), and tantalum (Ta). These metals have not been investigated for use as catalytic electrodes in a peroxide fuel cell setting. However, they have been used as catalysts in related or close fields. A modified Dy catalyst was employed for low-temperature selective catalytic reduction denitrification, Tb mixed oxides were investigated as an alternative for three-way catalysts in engines, and Gd-based photocatalysts have demonstrated favourable properties for environmental remediation [14; 15; 16; 17]. Dy, Tb, Er, Gd, and Ho were selected as representatives of rare metals that are non-hazardous and relatively inexpensive. Sb and Ta were selected as metals as they also have been used as catalysts in previous research papers. Ta has the added attribute of being resilient against corrosion in harsh chemical conditions such as extreme pH and highly oxidizing settings, like a fuel cell. This study compares the electrocatalytic performances and constructs plausible theories to explain the observed results and the catalytic mechanisms. Key findings from these investigations include that Dy, Er, Gd, Ho, and Tb can function as electrocatalytic electrode materials to produce a moderate cell output potential in the range of 0.14 V to 0.16 V in alkaline hydrogen peroxide electrolytes. (Sb) and (Ta) functioned as the highest-performing electrode in neutral (0.307 V and 0.2 V) and acidic (0.521 V and 0.457 V) electrolytes, respectively. Ta can also perform well in alkaline electrolytes with an output potential of 0.146 V. It was also observed that an acidic electrolyte leads to a more stable and greater energy output.