The current or voltage fluctuation in fuel cell operation is harmful to the fuel cell system and power application equipment. Here, we report a technique to eliminate such a fluctuation by the aid of new type of catalysts, superlattice-like mesoporous PtCo catalysts. The current fluctuation in fuel cells catalyzed by two invented catalysts are fixed at as low as 25 mA·cm⁻² with a power of 0.75 W·cm⁻² or 120 mA·cm⁻² with a power of 1.01 W·cm⁻², and no noticeable current decay was detected over 100 h. By contrast, a cell catalyzed by conventional Pt/C catalysts with the same Pt loading delivered a current fluctuation as large as 180 mA·cm⁻² even at low power output of 0.30 W·cm⁻², which also showed 32% current decay rate in 50 h. The superlattices-like mesoporous structure not only enhances the mass transfer and depresses the water flooding but also effectively increases the Pt utilization within its 3D carbon frameworks. Its power output was as high as 11.69 W·mg_Pt⁻¹ (MEA), which is 46.1% higher than the 2025 target of DOE, USA, 8.0 W·mg_Pt⁻¹(MEA).