Synthesis and Electrochemical Characterization of Ru-Modified Iridium Oxide Catalysts for PEM Electrolysis

Abstract

In the search of sustainable energy solutions, proton exchange membrane water electrolyzers (PEMWEs) have emerged as a promising alternative for sustainable clean hydrogen production. This study focuses on synthesis and characterization of Ruthenium (Ru)-modified iridium oxide (IrO₂) catalysts. The anode is the principal reason for the high overpotential of PEMWEs and it also greatly increases the cost of the electrolyzers. IrO₂ is highly stable and corrosion-resistant, particularly in acidic environments, making it a durable catalyst for the oxygen evolution reaction (OER) in PEMWEs, though it suffers from a relatively high overpotential. Ruthenium oxide (RuO₂), on the other hand, is more catalytically active with a lower overpotential, but is less stable under the same conditions. In this study, the goal was to improve the catalytic activity and stability of the anode catalyst, IrO₂, through the controlled incorporation of Ru and to reduce overall catalyst cost due to the reduced iridium content. This synergistic combination allows for better performance in terms of conductivity, efficiency, and durability, making Ru-modified IrO₂ an ideal catalyst for OER in PEMWE applications. The Adams fusion method was adapted and used to synthesize the catalysts. The modified catalysts were characterized using analytical instruments. These analyses provided insights into the structural, morphological, and electrochemical properties of the Ru-modified IrO₂ catalysts.

1. Introduction

The increase in the global population is causing a global energy crisis and a demand for alternative energy sources, such as renewable energy sources [1,2,3]. Consumption of fossil fuels increases the risk of global warming, raising concern among the public [1,3] Fossil fuels are limited energy resources compared to renewable energy sources such as solar energy, which is used to generate green hydrogen [2]. Globally, climate change disproportionately affects the most disadvantaged and vulnerable people [4]. Sustainable objectives that set the stage for climate change-resistant and low-carbon development were established by the UN Sustainable Development Goals (SDGs) and the Paris Climate Agreement (PCA) in the year 2015 [4]. The SDGs must be achieved soon to stop climate change and mitigate its effects [4]. Energy consumption in the end-use sector, namely transport, buildings, and industry, will also have to be considered to achieve time targets for decarbonization because increasing the options available will offer the best opportunity for doing so [4].

Using fossil fuels as an energy source causes significant pollution. The burning of fossil fuels produces SO_2, which is the cause of acid rain [3]. Large amounts of greenhouse gasses being released into the atmosphere have caused concern globally, which has led to an international agreement on the reduction of CO₂ emissions known as the Kyoto Protocol [1,3].

Hydrogen has become a widespread energy source in recent years, and this is due to it being greener compared to fossil fuels [3]. Hydrogen is produced by an electrochemical process called electrolysis, where water is split into oxygen and hydrogen [2]. Hydrogen as an energy carrier has benefits over hydrocarbon fuels, including its high specific energy density, and does not emit pollutants such as CO₂ [2]. Global hydrogen production for chemical industries, fertilizer production, iron refineries and oil refineries, is estimated to be around 95 MtH₂ per year in 2022 [5]. The Institute for Energy Economics and Financial Analysis (IEEFA) conservatively estimates that around 2.9 million tonnes of hydrogen per year could be produced from sustainable energy sources by 2030 [6]. The demand for hydrogen will continue to increase yearly. Alternative cheap electrochemical catalysts used in PEMWE for hydrogen production need to be developed. The high cost associated with components such as precious metal catalysts and the proton conducting membrane is the primary challenge facing the Proton Exchange Membrane (PEM) water electrolyzer [7]. Significant efforts by various researchers aiming to reduce the cost of the PEM water electrolyzer electrocatalysts and improve their specific performance and durability using the precious metal loading requirement have been conducted [7,8,9].

At the anode, the electrocatalyst plays a critical role as it undergoes the oxygen evolution reaction (OER), exhibiting the highest overpotential in standard operating conditions [7,9]. Similar to the oxygen reduction reaction (ORR) in Proton Exchange Membrane Fuel Cells (PEMFC), the OER is kinetically sluggish, since it is thermodynamically and kinetically unfavorable to remove four electrons for oxygen–oxygen bond formation [9].

Among metal oxides, IrO₂ exhibits good durability with the second-best activity, while RuO₂ exhibits the highest activity with poor durability [10]. Several methods have been studied for synthesizing nano-sized metal oxides, including Adams fusion, the molten salt method, metal–organic chemical vapor deposition method, sulphite complex route method, sol–gel method, modified polyol method, and hydrothermal method [7]. However, in the context of the scaling-up process, some of these methods involve steps requiring complex equipment and present technical and economic challenges [7].

In this study, research was carried out to synthesize nanostructured Ru-modified IrO₂ electrocatalysts to improve the catalytic activity and the corrosion stability of the modified metal oxide compared to pure noble metal oxide electrocatalysts and to reduce the cost of the catalysts. Modifying IrO₂ catalysts with ruthenium (Ru) presents a promising avenue to overcome the challenges associated with pure IrO₂ and unlock improved performance in PEM electrolyzers. Ruthenium, characterized by lower cost and relatively more abundant supply than iridium, addresses the economic barriers associated with IrO₂ catalysts. Furthermore, incorporating Ru can significantly enhance the electrochemical activity of the catalyst, reducing the overpotential required for the OER. This translates to improved energy efficiency and reduced electrolysis costs. Moreover, Ru modification can potentially mitigate the stability issues of IrO₂ by providing enhanced structural stability and resistance to degradation under harsh operating conditions. The synergistic effects of the IrO₂-Ru hybrid catalyst hold promise for achieving high catalytic performance, increased durability, and cost-effectiveness, thereby accelerating the adoption of PEM electrolyzers for sustainable hydrogen production.

2. Electrolysers

2.1. Alkaline Water Electrolyser

Alkaline water electrolysis uses an aqueous electrolyte solution consisting of approximately 20–30% KOH or NaOH and operates at relatively low temperatures (60–80 °C) [11]. Nickel-based materials and separators such as zirfon and asbestos fabricate the anode and cathode electrodes. In the alkaline process, two moles of water are reduced to one mole of H₂ and two OH⁻ ions at the cathode [11]. The resulting H₂ is released from the cathodic surface. The electric potential between the anode and the cathode force the hydroxile ions through a porous separator to the anode side where they are oxidized at the anode to produce half a molecule of O₂ and one molecule of H₂O [11].

The limitations to alkaline water electrolysis include limited current density, reduced partial load, and low operating pressure, which can lead to reduced energy efficiency [12]. Consequently, there is a promise within the field of ALK water electrolysis technologies for assessing anionic conductive polymer-based AEMs with alternative asbestos diaphragms [11].

2.2. Anion Exchange Membrane(AEM) Water Electrolyser

AEM electrolysis uses distilled water, or a low concentration alkaline solution compared to water electrolysis, where a concentrated ALK solution is usually used as electrolyte [13]. AEM electrolysis technologies are currently under the development stage to the kW scale and require further investigation. Anode and cathode catalytic electrodes primarily utilize Ni and NiFeCo-based alloy materials. Standard AEMs include quaternary ammonium ion exchange membranes, such as Fumasep^® FAA3, Tokuyama A201, Ionomr Aemion™, Dioxide materials Sustainion^® [14]. The gas diffusion layers are Ni-foam, porous Ni-mesh, or C-cloths for both the anode and cathode. Ni-coated stainless steel and stainless-steel separator plates are used as bipolar plates and end plates [13]. Challenges the AEM water electrolyzers face include limited stability and high hydrogen production cost, and these hinder the commercialization of AEM water electrolyzer systems.

2.3. Solid Oxide Electrolyser

In solid oxide electrolysis, steam at the anode combines with electrons from the external circuit to form hydrogen gas and negatively charged oxygen ions. The oxygen ions pass through the solid ceramic membrane and gets reduced at the cathode to form oxygen gas and generate electrons for the external circuit.

The solid oxide electrolyzer cell has two capabilities that stand out: its ability to perform high-temperature electrolysis and smooth integration with industrial processes, thus enabling improvement in overall efficiency in the hydrogen production process. Conventional SOE makes use of O²⁻ conductors made from nickel/yttria stabilized zirconia; however, now, the use of ceramic proton conducting materials exhibits superior efficiency at high operating temperatures [15]. Comparing the efficiency of the SOE to AKL and AEM, each is ~80%, ~78%, and ~59%, respectively [16]. However, SOE technology suffers from lack of stability, which hinders the commercialization of it [15].

2.4. Proton Exchange Membrane Water Electrolyser

Recently much attention has been paid to the production of H₂ from H₂O using a proton exchange membrane (PEM) water electrolyzer [17]. Grubbs in the 1950s introduced the concept of PEM electrolysis [18,19], which was advanced by General Electric Co. in 1966 [15,20]. The PEM fuel cell technology is similar to PEM water electrolysis technology, as both technologies utilize a solid polysulfonated membrane (Nafion^®) which acts as an electrolyte [11]. The membrane exhibits many advantages such as low gas permeability, high proton conductivity and high-pressure operational capacity [11]. Normal operation of the PEM water electrolysis is between 20–80 °C with high current densities (<2 A/cm²) and produces high purity (99.999%) of H₂ and O₂ gasses [11].

PEM technology has received attention by many water electrolyzer manufacturers for industrial and transportation applications since it has a smaller carbon footprint and an absence of hazard electrolytes, as well as being safer compared to ALK water electrolysis [21].

3. Anode Catalysts for the Proton Exchange Membrane Water Electrolyzer

The use of catalysts plays an important role in effectively facilitating the oxygen evolution reaction (OER) to produce O₂ from the oxidation of H₂O at the anode of the water electrolyzer. Therefore, it is important to develop an electrocatalyst which is highly conductive and has high stability. The acidic environment of the PEM water electrolyzer destabilizes transition metals such as Ni, Co, and Mn, thus these metals undergo corrosion which increases the risk of poisoning the membrane.

3.1. Iridium Oxide

One of the commonly used electrocatalysts for the oxygen evolution reaction (OER) due to its high stability, it is considered ‘the-state-of-the-art’ OER catalyst. According to [7], IrO₂ is one of the catalysts that exhibit the required stability and activity for use in acidic solid electrolyte environments. Applications of IrO₂ other than in electrocatalysts include field emission, sensing, electrical properties, and Li-air batteries [22,23]. Arico et al. demonstrated the effect of reaction conditions on the morphology of the IrO₂ [24].

3.2. Ruthenium Oxide

RuO₂ exhibits higher OER activity in a low overpotential range but with lower stability [24]. Combining iridium and ruthenium to form an oxide is known as a binary metal oxide (Ir_x−1Ru_xO₂.). According to Adamson et al. [25], binary metal oxides exhibit the following properties: enhanced electrocatalytic activity [26], favorable morphologic for ion transfer [27], and the creation of unique crystal interfaces [28]. Wang et al. [29] report on the superior activity and enhanced cell efficiency shown by the Ir_0.7Ru_0.3O₂ catalyst. When Wang et al. [29] studied the effect of different preparation conditions on the Ir_0.7Ru_0.3O₂ catalyst, it was found that leaching Ru in Ir_0.7Ru_0.3O₂ (EC) showed 13-fold higher OER activity than Ir_0.7Ru_0.3O₂ (TT). It was noted that, in the initial catalysis stage, the Ru component in Ir_0.7Ru_0.3O₂ was unstable [29].

Ir mitigates the degradation of RuO₂ during prolonged electrochemical operations, leading to a longer-lasting electrode. This synergy between Ir and Ru enhances the overall performance and stability of the anode, making it more effective for applications such as the OER in water electrolysis. The presence of RuO₂ alongside IrO₂ provides additional active sites for the OER, thereby improving the rate of oxygen production and lowering the activation energy required for the reaction.

4. Material and Methodology

4.1. Chemicals and Apparatus

The chemicals used for the synthesis of the Ru-modified IrO₂ catalyst and to prepare and test the working electrode (WE) were H₂IrCl₆; RuCl₃; NaNO₃; Isopropanol; IrO₂ commercial; and RuO₂ commercial, respectively. The chemicals used for the preparation of the working electrode (WE) were Nafion^® Solution 5 wt%; Isopropanol; and Ultrapure H₂O with a resistance of 18.2 MΩ.cm.

The apparatuses used during synthesis and electrochemical testing were a magnetic stirrer and hotplate; water bath; drying oven; ultrasonic bath; muffle furnace; and a PGSTAT302N Potentiostat/Galvanostat with working electrode (WE), counter electrode (CE), and reference electrode (RE).

4.2. Synthesis of Ir_0.8Ru_0.2O₂ Catalyst

4.2.1. Modified Adams Fusion Method

A predetermined amount of 0.36 g of total precursor salt (amounting to a ratio of 0.8:0.2 of iridium precursor to ruthenium precursor) was dissolved in 10 mL isopropanol and magnetically stirred for 30 min at 250–300 rotation per minute (rpm). An amount of finely grounded NaNO₃ was added to the mixture and stirred for another 30 min. The mixture was then placed on a hot plate set at 80 °C to evaporate excess isopropanol and then further dried in an oven for 10 min at 80 °C. The dried mixture was transferred to a porcelain crucible. The crucible with the dried mixture was placed into a preheated furnace at 350 °C for 2 h. After the synthesis duration of 2 h, the mixture was taken out of the furnace and left to cool overnight. The obtained metal oxide was filtered using approximately 2 L of ultrapure H₂O to ensure that unreacted salt was removed. A solution of 0.1 M AgNO₃ was used to the filtrate to ensure there was no chlorine present. Finally, the Ir_0.8Ru_0.2O₂ was dried in a preheated oven at 80 °C overnight.

The Ir:Ru ratio and synthesis temperature were determined from the literature and the optimized ratio was used in this research.

4.2.2. Preparation of Working Electrode

For all electrochemical measurements, a glassy carbon (GC) working electrode (WE) was used. To clean the GC, a 0.05 μm alumina paste was used to polish the GC. Thereafter, the GC was placed in an ultrasonic H₂O bath to further remove surface particles. Figure 1 shows how the GC was polished and cleaned [30].

The catalyst ink was prepared by dispersing 8 mg of electrocatalyst, 50 μL Nafion solution (5 wt%), and 1950 μL ultrapure H₂O using an ultrasonic homogenizer for 15 min. A total of 30 μL of electrocatalyst was dropped onto the GC WE with a micropipette. The ink was dried at room temperature overnight and the GC and WE were covered by a beaker to prevent them from falling onto the wet ink. Before electrochemical measurements were taken, the GC and WE were rotated for 15 min to ensure the ink was dry.

4.2.3. Electrochemical Characterization

In this study, a three-electrode electrochemical cell was used for the electrochemical measurements. All tests were performed at 25 °C using a warm bath and 1 atm using the Autolab potentiostat PGSTAT302N. The cell setup was in electrolyte of 0.5 M H₂SO_4(aq) with the 3 electrodes, the GC with catalyst coat, a 3 M Ag/AgCl, and a 1 Pt sheet which are the WC, RE, and CE, respectively. All potentials in this experiment were calibrated from the 3 M Ag/AgCl electrode to the RHE, since the Ag/AgCl had a positive potential shift of +0.21 V compared to the RHE [8] The cell was purged using N₂ for 15 min, and thereafter, an electrode activation was performed using CV at a scan rate of 0.02 V/s for 50 cycles to remove any impurities on the surface of the WE. The cell setup used in this experiment can be seen in Figure 2 below. The parameters for the cyclic voltammetry are shown in

Table 1. The parameters of the CV (Cyclic voltammetry) analysis [31].

Start potential	0.02 V
Upper vertex potential	1.2 V
Lower vortex potential	−0.2 V
Stop potential	0.02 V
Number of scans	3
Scan rate	0.02 V/s
Step	0.00244 V
Interval time	0.12207 s

,

Table 2. The parameters of the LSV (Linear sweep voltammetry) analysis [31].

Start potential	0.8 V vs. RHE
Stop potential	1.8 V vs. RHE
Scan rate	0.002 V/s
Step	0.00244 V
Interval time	1.2207 s
Current range	1 mA–100 nA
Rotation speed	1600 rpm

shows the parameters for linear sweep voltammetry analysis and

Table 3. The parameters of CP (Chronopotentiometry) analysis [31].

Applied current	0.02 A/cm2
Maximum cutoff voltage	1.8 V vs. RHE
Rotation speed	1600 rpm

shows the parameters for CP (Chronopotentiometry) analysis.

5. Results and Discussion

Modified catalysts: Physical and electrochemical characterization of in-house Ir_0.8Ru_0.2O₂ catalyst.

There have been extensive studies of Ir-Ru mixed oxides for many years. According to the literature, the addition of Ru to IrO₂ improves the electrocatalytic activity of IrO₂ [32,33]. In this study, IrO₂ was modified by adding Ru, the composition of Ru to Ir was determined by in-house (IH) literature and, according [33] to the best performing Ru-modified IrO₂ catalyst, had a composition ratio of Ir to Ru of 0.8:0.2 respectively.

The EDS results of IrO₂ commercial, RuO₂ commercial, and Ir_0.8Ru_0.2O₂-IH are represented by 3. The data from EDS shows trace amounts of impurities in the IrO₂, which could be due to the synthesis procedure, or the trace amounts were detected from the tray the analyte was placed in. However, both the RuO₂ and Ir_0.8Ru_0.2O₂-IH samples were found to be pure the ratio of Ir to Ru was found to be 0.8:0.2, respectively.

Table 4. Elemental composition of commercial and IH samples.

Weight %	IrO2 Commerczial	RuO2 Commercial	IrRuO2 IH
O	17.30	30.53	25.90
Ru	0.00	69.47	16.73
Ir	69.43	0.00	57.37
K	3.72	0.00	0.00
Ti	0.11	0.00	0.00
Cr	1.80	0.00	0.00
Fe	7.16	0.00	0.00
Na	0.03	0.00	0.00
Ir/Ru	0.00	0.00	0.8/0.2

shows the elemental composition of commercial and IH samples.

Figure 3 shows the XRD spectra of the IH-Ir_0.8Ru_0.2O₂ catalyst synthesized at 350 °C as well as both commercial IrO₂ and RuO₂ catalysts. The IrO₂ and RuO₂ standard peaks were assigned using the data available from the JCPDS database. Both commercial catalysts IrO₂ and RuO₂ represent a similar presence of the crystalline phase, which is confirmed when their similar characteristic phases are cross-referenced with the JCPDS database, JCP2-43-1019 for IrO₂ and JCP2-40-1290 for RuO₂ [34]. Comparing the peaks of the IH-Ru-modified IrO₂ to the commercial catalysts (IrO₂ and RuO₂), the commercial catalysts have narrower peaks compared to IH-Ru-modified IrO₂ catalyst. This indicates that the IH-Ru-modified IrO₂ is more amorphous in nature and the commercial catalysts being more crystalline in nature. According to literature, the amorphous phase usually has smaller particle size than the crystalline phase [35]. For both commercial samples, the (110) facet is there the main diffraction peaks however, the (101) facet was the main diffraction peak for the IH sample, and a similar result was achieved by [7] by using a synthesis temperature of 350 °C. The crystallite sizes at each facet were calculated using the Scherrer formula below.

$$d_p={\displaystyle \frac{K\lambda }{\beta cos\theta }}$$

(1)

The crystallite sizesw for the (110), (101) and (211) facets were calculated using Equation (1) and reported in

Table 5. XRD d-spacing and average crystallite size of commercial catalyst and IH Ru-modified IrO₂ calculated using Scherrer equation.

Sample Name	d(110) (nm)	d(101) (nm)	d(211) (nm)	Average Size (nm)
IrO2 commercial	14.80	11.87	12.33	13.00
RuO2 commercial	20.93	20.95	26.26	22.71
Ir0.8Ru0.2O2 IH	1.61	2.08	2.21	1.97

along with the average crystallite sizes of both the commercial and IH samples.

Figure 4 shows the surface morphology of the IH Ru-modified IrO₂ and the commercial IrO₂ and RuO₂ catalyst at a scale of 100 nm. There is a drastic change in the surface morphology of the IH sample compared to the commercial samples. XRD and BET results correlate to the change in surface morphology, where the IH sample has a smoother surface compared to the commercial samples.

Figure 5 represents the TEM images of the IH Ru-modified IrO₂ and, commercial IrO₂ and RuO₂. The TEM image of the IH samples shows small particles that are extremely agglomerated compared to the commercial samples, thus making it difficult to particle size. The commercial samples in Figure 5a,c show cubic particles. The particle size of the IH Ir_0.8Ru_0.2O₂ and commercial IrO₂ and RuO₂ are reported below.

Figure 6 represents the N₂ adsorption–desorption analysis for commercial IrO₂ and RuO₂ and Ir_0.8Ru_0.2O₂-IH. Both the Ir_0.8Ru_0.2O₂-IH and commercial RuO₂ show distinct hysteresis loops; however, the IrO₂ does not have the hysteresis loop. The BET surface area reported in

Table 6. BET surface area and pore size of commercial IrO₂ and RuO₂, and Ir_0.8Ru_0.2O₂-IH.

Sample Name	BET Surface Area (m2/g)	Pore Size (nm)
IrO2 commercial	5.75	19.91
RuO2 commercial	8.40	13.95
Ir0.8Ru0.2O2-IH	205.64	2.52

shows that Ir_0.8Ru_0.2O₂-IH has the largest surface area compared to the commercial RuO₂ catalysts, with IrO₂ having the smallest surface area. The significant increase in surface area for the Ir_0.8Ru_0.2O₂-IH sample compared to the commercial IrO₂ and RuO₂ samples is attributed to the nature of synthesized Ir_0.8Ru_0.2O_2, which is amorphous. Amorphous materials usually have higher surface areas due to their irregular structure and the random arrangement of atoms, which creates more surface irregularities and pores.

There is a direct correlation between surface area and pore size, with the IH sample having the smallest pore size and commercial IrO₂ having a larger pore size. The BET results correlate with the results found in TEM, SEM and XRD.

Figure 7 represents the CV analysis of Ir_0.8Ru_0.2O₂-IH and commercial IrO₂ and RuO₂. The addition of Ru to IrO₂ caused the CV of Ir_0.8Ru_0.2O₂-IH to resemble that of RuO₂ more than IrO₂ with a distinct negative tail at the cathodic potential scan at 0 V vs. RHE, which is attributed to hydrogen adsorption (H_ads) [7,32]. The Ir(III)/Ir(IV) and Ir(IV)/Ir(V) redox couples are reported in

Table 7. Comparison of Commercial and Synthesized IrO2.

Sample Name	Ir(III)/Ir(IV) Redox Couple (V vs. RHE)	Ir(IV)/Ir(V) Redox Couple (V vs. RHE)
IrO2 commercial	0.74	1.26
Ir0.8Ru0.2O2-IH	0.65	1.22

. An extra peak can be seen for the commercial IrO₂ which was reported by [33] and suggested it could be the presence of active Ir(III) sites.

Figure 8 represents the LSV analysis of Ir_0.8Ru_0.2O₂-IH and commercial IrO₂ and RuO₂. LSV results show an increase in catalytic activity for OER with the addition of Ru to IrO₂, which is expected since RuO₂ is known to have higher catalytic activity than IrO₂. However, as seen in Figure 8, the catalytic activity of RuO₂ decreases with increased potential. This result is due to the harsh acidic environment which causes corrosion and catalyst degradation, making the RuO₂ catalyst less stable than IrO₂.

Table 8. Current densities of commercial IrO₂ and RuO₂, and Ir_0.8Ru_0.2O₂-IH at operational voltage of 1.7 V.

	IrO2 Commercial	RuO2 Commercial	Ir0.8Ru0.2O2-IH
Operational voltage (V)	1.7	1.7	1.7
Current density (Acm−2)	0.099	0.078	0.26

represents the current densities of Ir_0.8Ru_0.2O₂-IH and commercial IrO₂ and RuO₂ at the operational potential of 1.7 V as this is the typical potential a PEM electrolyzer operates. From the results reported in Table 8, it is seen that Ir_0.8Ru_0.2O₂-IH is 3 times more active than both commercial IrO₂ and RuO₂.

CP studies the OER stability of the catalyst at a fixed current, Figure 9 shows the CP results of the Ir_0.8Ru_0.2O₂-IH and commercial IrO₂ and RuO₂ that were obtained at the current density of 10 mA.cm⁻².

Table 9. OER stability of commercial IrO₂ and RuO₂, and Ir_0.8Ru_0.2O₂-IH in 0.5 M of H₂SO₄ electrolyte [31].

Sample Name	OER Stability (h)
IrO2 commercial	5
RuO2 commercial	3
Ir0.8Ru0.2O2-IH	24

shows the summary of the OER stability of the same catalysts. The Ir_0.8Ru_0.2O₂-IH sample had excellent stability at a constant potential of ±1.5 V over 24 h. This result is significant compared to the commercial sample, with RuO₂ being the least stable, shown in both Figure 9 and Table 9.

6. Conclusions

This study focused on a bimetallic anode of Ir_0.8Ru_0.2O₂-IH, compared with single-metal IrO₂ and RuO₂ electrodes to assess performance in oxygen evolution reactions (OER). By benchmarking RuO₂ and using it to support IrO₂, the study demonstrated the enhanced catalytic activity and stability of the bimetallic anode over single metal oxides, showcasing the benefits of metal combinations in improving electrochemical performance. The ratio of Ir/Ru was optimized based on the best-performing mixed metal oxide, synthesized via a modified Adams fusion method. The resulting Ru-modified IrO₂ catalyst showed superior electrocatalytic activity and stability compared to commercial IrO₂ and RuO₂, with an extended operational stability of around 24 h. XRD and TEM analyses revealed that adding Ru to IrO₂ produced amorphous particles at 350 °C, while BET analysis indicated a larger surface area and smaller pore size in the synthesized catalyst. These improvements suggest that the modified catalyst is highly suitable for water electrolysis applications.