As an effective electrocatalyst for water decomposition, precious metals face limitations in widespread use due to their high cost. Incorporating other metals into precious metals to enhance electrocatalytic performance while reducing costs poses significant challenges. Within the realm of precious metals, Ir-based electrocatalysts have demonstrated remarkable catalytic activity for both oxygen evolution (OER) and hydrogen evolution (HER). This paper presents the synthesis of oxide-supported Ir-based catalysts containing Cu and Ce through a straightforward polyol reduction method. These catalysts exhibit notable OER and HER activity in acidic electrolytes. The addition of Ce increases oxygen vacancy, enhancing the catalytic performance of the optimized Ir3Cu0.5Ce0.5Ox/C clusters, surpassing IrO2 in OER with an overpotential of 274 mV at 10 mA cm−2. Moreover, these catalysts demonstrate outstanding performance when utilized as cathodes and anodes in H-type electrolytic cells. Overall, this study represents a significant advancement in the development of novel Ir-based electrocatalysts.