Hydrogen loading and reduction of iron oxides on steel studied by XPS with an in situ cell
Benedikt Wolfsjäger, Jiri Duchoslav, Philipp Kürnsteiner, Reza Sharif, Thomas Steck, David Stifter, Heiko Groiß
Abstract
• Custom-made in situ cell for hydrogen charging in XPS is presented. • Iron oxide reduction was observed in the high-resolution Fe2p spectrum. • Thickness of oxide layers was calculated with the modified Strohmeier equation. • Identification of the reaction mechanism of iron oxide reduction. A self-developed liquid in situ cell gives insights into the diffusion of hydrogen in steel and its interaction with iron oxides. The cell initiates a corrosive reaction on one side of a galvanized steel sample within an X-ray photoelectron spectroscopy (XPS) system while changes of iron oxides on the opposite side attributed to diffused hydrogen are recorded. The reduction leads to a continuous alteration in the high-resolution Fe2p peak which is iteratively measured during hydrogen permeation. A detailed analysis of the process, involving layer thickness evaluation with the modified Strohmeier equation leads to a model of the developed oxide structure.