Corrosion inhibition mechanisms of metal-organic frameworks in ammonia-rich environments.

A range of metal-organic framework (MOF)-based composite materials were synthesized and assessed for their corrosion inhibition properties in ammonia-containing aqueous environments. The interaction mechanisms of these materials with copper surfaces were systematically investigated using electrochemical techniques and surface characterization methods. Based on these analyses, a comprehensive mechanistic model was developed to explain the interplay of the observed factors. The results demonstrated that the corrosion inhibition performance of zeolitic imidazolate frameworks (ZIFs), a representative class of MOFs, is significantly influenced by the surrounding environment. Specifically, experimental analysis revealed a competitive interaction between NH₃ and the ZIF ligand in complex reactions, leading to structural instability of the ZIFs. This instability compromises the protective layer formed on the copper surface, resulting in a reduction of up to 60% in corrosion inhibition efficiency and, consequently, insufficient long-term durability.