Tailored metal–organic frameworks with tunable physicochemical properties not only render integration of electroactive species but also facilitate the accessibility of catalytic sites, yet much less discussed for electrocatalysis. Herein, we report a rational shaping of core-shell Zeolitic Imidazolate Frameworks in a scalable seed mediated approach. The Pd encapsulated robust ZIF-8/ZIF-67 nanoarchitectures exhibit highly efficient electrocatalytic oxygen evolution reaction (OER) with low Tafel slope of 85 mV/dec and a 340 mV overpotential. The heterojunction favours a well-matched band energy, efficient charge mobility with exceptional OER with 10 mA cm^–2 anodic current density, high turnover frequency (TOF: 1.21 sec^–1), high Faradaic efficiency (91.88 %) and long-term durability as well as stability. The local structure and electrical information of Pd nanoparticles as well as their beneficial cooperative impact on ZIF-8/ZIF-67 affirmed by EXAFS and XANES analyses. Furthermore, DFT studies are harmonious with the experiments, that highly active molecules have a strong synergistic effect for the overall electrocatalytic OER performance exhibited by the catalysts, which elucidate the role of active Pd and Co sites and corroborate the experimental findings.