Recent Advances in Heterogeneous Catalytic Systems Containing Metal Ions for Phosphate Ester Hydrolysis

Abstract

Organophosphates are a class of organic compounds that are important for living organisms, forming the building blocks for DNA, RNA, and some essential cofactors. Furthermore, non‐natural organophosphates are widely used in industrial applications, including as pesticides; in laundry detergents; and, unfortunately, as chemical weapons agents. In some cases, the natural degradation of organophosphates can take thousands of years; this longevity creates problems associated with handling and the storage of waste generated by such phosphate esters, in particular. Efforts to develop new catalysts for the cleavage of phosphate esters have progressed in recent decades, mainly in the area of homogeneous catalysis. In contrast, the development of heterogeneous catalysts for the hydrolysis of organophosphates has not been as prominent. Herein, examples of heterogeneous systems are described and the importance of the development of heterogeneous catalysts applicable to organophosphate hydrolysis is highlighted, shedding light on recent advances related to different solid matrices that have been employed.

Heterogeneous Catalysis of Lanthanoid Ions for the Hydrolysis of p-Nitrophenyl Phosphate Enhanced by Incorporation to Cyano-Bridged Heterometallic Coordination Polymers

“…Organophosphates at high concentrations can be efficiently degraded by catalytic materials. − In nature, a series of enzymes such as phosphatase and phosphodiesterase are used as catalysts for the hydrolytic decomposition of organophosphates. − Many enzymes hold metal ions at active sites. In this context, metal ions such as zinc, copper, cobalt, and mercury ions have been used as homogeneous catalysts for the hydrolysis of organophosphates. − Lanthanoid (Ln) ions are also available as the hydrolysis catalysts due to their strong Lewis acidity in aqueous solutions. − Recently, the higher catalytic activity of cerium­(IV) ions than 3d-metal ions has been reported for organophosphates hydrolysis because 4f orbitals of Ce IV ion readily interact with the orbitals of the phosphate group in an organophosphate. − …”

Hydrolysis of Organophosphorus Agents Catalyzed by Cobalt Nanoparticles Supported on Three-Dimensional Nitrogen-Doped Graphene

“…Organophosphorus agents (OPs) are used often as pesticides, nerve agents, and plasticizers, 1 and they can deactivate acetylcholinesterase, which may cause further severe diseases for humans. 2 Catalytic chemical degradations and other protocols have been used for the removal and/or degradation of OPs.…”

“…Organophosphorus agents (OPs) are used often as pesticides, nerve agents, and plasticizers, and they can deactivate acetylcholinesterase, which may cause further severe diseases for humans . Catalytic chemical degradations and other protocols have been used for the removal and/or degradation of OPs. − Early on, organophosphorus hydrolases (OPHs) were utilized as catalysts for the degradation of OPs. − However, the poor stability and limited availability of OPHs are the drawbacks for practical applications.…”