On Transition Metal Catalyzed Reduction of N-nitrosodimethlamine

TL;DR

This paper reviews the effectiveness of various metal-based catalysts, especially palladium, copper, and nickel, in reducing the water contaminant N-nitrosodimethylamine (NDMA) using hydrogen, highlighting their kinetics and proposed mechanisms.

Contribution

It provides a comparative analysis of monometallic and bimetallic catalysts for NDMA reduction, introducing a surface-activated reaction mechanism for palladium and nickel.

Findings

Palladium, copper-enhanced palladium, and nickel are highly efficient catalysts.

Half-lives for NDMA reduction are on the order of hours per 10 mg/l catalyst metal.

No intermediates detected in preliminary LC-MS analysis.

Abstract

This report provides a critical review on "Metal-Catalyzed Reduction of N-Nitrosodimethylamine with Hydrogen in Water", by Davie et al. N-nitrosodimethlamine (NDMA) is a contaminant in drinking and ground water which is difficult to remove by conventional physical methods, such as air stripping. Based on the reported robust capability of metal based powder shaped catalysts in hydrogen reduction, several monometallic and bimetallic catalyst are studied in this paper on the reduction of NDMA with hydrogen. Two kinds of kinetics, metal weight normalized and surface area normalized, are compared between each catalyst in terms of pseudo-first order reaction rate. Palladium, copper enhanced palladium and nickel are found to be very efficient in NDMA reduction, with half-lives on the order of hours per 10 mg/l catalyst metal. Preliminary LC-MS data and carbon balance showed no intermediates. Finally, a simple hydrogen and NMDA surface activated reaction mechanism is proposed by the author for palladium and nickel.