Role and behavior of ultra-thin gold films on the fiber materials surface in the CO oxidation process

Abstract

The work continues a series of studies aimed at enhancing catalytic properties of metal fibers formed by the pendant drop melt extraction (PDME) method. In this paper, we show that deposition of the thin gold film on the metal fibers leads to a change in the catalytic performance of the samples under study. Au-coated fibers of titanium, zirconium and alloys of the Fe–Cr–Al, Ni–Cr–Al–Y, Ni–Cr–Al–Pt–Ir–Hf, Ni–Cu–Fe–Mn systems were tested as catalysts in the reaction of CO oxidation. We have found that the deposition of gold makes titanium, zirconium, and Fe–Cr–Al fibers catalytically active, while in the initial state they have not shown any evidence of catalytic activity. In the case of Ni–Cu–Fe–Mn fibers, which could oxidize CO themselves, the deposition of Au film significantly increases their catalytic properties. It was found that during the catalytic process, gold film coalesces to droplets with the predominant size of 11–14 nm.