Hydrogen production through electrochemical routes, particularly via urea-assisted water splitting, offers a sustainable and energy-efficient pathway for clean fuel generation. However, the development of robust and cost-effective electrocatalysts capable of simultaneously promoting the hydrogen evolution reaction (HER) and urea oxidation reaction (UOR) remains a major challenge. In this work, a quaternary NiCoMnP electrocatalyst was synthesized using the Dynamic Hydrogen Bubble Template (DHBT) technique to engineer a hierarchical three-dimensional porous structure that maximizes active site exposure and facilitates charge transport. Comprehensive structural and compositional analyses confirmed that deposition above a critical current density threshold induced the formation of a uniform, interconnected porous network. The optimized NiCoMnP catalyst exhibited outstanding HER activity, requiring only 60 mV overpotential (η10 vs. RHE), which represents a 65–74 % reduction relative to binary and ternary analogues. Moreover, long-term electrolysis demonstrated excellent durability, with minimal (≈8 %) voltage fluctuation after 100 h of continuous urea oxidation. Post-stability examination showed negligible structural or compositional degradation, confirming the robustness of the catalyst. This study highlights that the strategic integration of multi-metallic alloying and DHBT-induced hierarchical porosity effectively enhances catalytic efficiency for sustainable hydrogen production from urea-containing solutions.

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