oa The Membrane Catalyst-Film Reactor (MCfR) Extends PGM Capability for Water Purification

Nanoparticles based on platinum group metals (PGMs) are effective for catalyzing reductions of widely occurring water contaminants, including nitrate (NO3-) and per- and poly-fluoroalkyl substances (PFAS).  This Short Article presents a new way to use PGMs that enable efficient use of hydrogen gas (H2) as the reductant to detoxify nitrate (NO3-), per- and poly-fluoroalkyl substances (PFAS), and other oxidized water contaminants.  The platform is a H2-based membrane catalytic-film reactor (MCfR).  The MCfR’s foundation is a Pd catalyst film that is in situ deposited on the outer surface of gas-transfer membranes.  H2 is provided to the membrane’s lumen, permeates the membrane’s wall, and is delivered directly to the base of the nanometer-thick catalytic film.  H2-delivery pressure, Pd loading on the membrane surface, and the alloying of Pd with other PGMs control the kinetics and selectivity of the reduction reactions.  The MCfR concept takes PGMs another step closer practical clean-water applications, by transitioning from suspended nanoparticles to immobilized nanofilms.