In the presented work, the possibility of direct synthesis of LDH (layered double hydroxide) on the AZ91 surface in the presence of a chelating agent (diethylenetriaminepentaacetic acid - DTPA) is reported. Conversion layer of LDH nanocontainers were formed under ambient pressure conditions without carbonate addition in the electrolyte. The obtained LDH was characterized using experimental (SEM, XRD, TGA, XPS, Raman, etc.) and computational methods (thermodynamic calculation, modeling of possible LDH crystal structures). A comparison of three possible LDHs (LDH-OH, -NO 3 and -CO 3 ) was performed. Based on the experimental results and crystal simulation approach, it was confirmed, that the mixed LDH-OH/CO 3 is grown on the surface in the presence of DTPA pentasodium salt.