The efficient and environmentally friendly removal of halogen substituents from organic substances is crucial for reducing the ecological and health hazards posed by persistent halogenated compounds. In this regard, we introduce CoN₃P₁@NP-PC, a novel asymmetric CoN₃P₁ single-atom catalyst, which demonstrates outstanding efficiency in transfer hydrodehalogenation (HDH) using just two equivalents of HCOONH₄ as a benign and effective reducing agent. This catalyst was synthesized through a simple post-implantation method, capitalizing on the high porosity and large surface area of ZIF-8 precursors. Extensive characterization via a range of spectroscopic and microscopic techniques confirmed CoN₃P₁@NP-PC's superior atomic dispersion and asymmetric structural integrity, which was more favourable for HCOONH₄ activation allowing facile generation of hydrogen radicals along with electron transfer. In our comprehensive evaluation, CoN₃P₁@NP-PC displayed outstanding versatility for the transformation of a diverse array of halogenated substrates, efficiently processing compounds with varied functional groups and complex molecular structures. Notably, CoN₃P₁@NP-PC proved particularly effective in breaking down brominated flame retardants such as 2,4,6-tribromophenol and tetrabromobisphenol A, reinforcing its potential as a powerful tool for ecological restoration and pollution control.