Prospects of Making Nanoporous Ruthenium from Transition Metal-Ru Alloys
Authors: El-Zoka Ayman Amr , Schweinar Kevin , da Silva Alisson Kwiatkowski , Raabe Dierk , Gault Baptiste 
Published: May 2020

Dealloying of Ag-Au alloys is known to produce Au-rich, bicontinous, nanoporous layers [1-2]. The high functionality of nanoporous gold, demonstrated in a variety of applications [3-4], invites us to study the fabrication of other nanoporous metals of interest by exploiting corrosion processes. Recent studies have shown how the use of ruthenium, which is the cheapest Pt-group metal, for catalysis could be expanded from the classical example of CO oxidation [5], to other important reactions such as hydrogen evolution [6]. Although several porous/non-porous Ru-containing systems have been studied before [7-8], there remains a knowledge-gap with regards to the design and optimization of Ru-based catalysts.

As a first step towards the development of nanoporous ruthenium by metal corrosion, this work shall focus on the design of binary transition metal-Ru systems. High resolution APT (atom probe tomography) studies of Ru-lean alloys (Fe-Ru and Ni-Ru) will assess the bulk microstructure of as-cast alloys and how it is affected by processing conditions [9]. Furthermore, pathways to inducing Ru-surface enrichment in different thermochemical environments (oxidative/inert/reductive) will be investigated by combined APT and XPS (X-ray photoelectron spectroscopy) [10]. The results of this study will provide guidance to making low-cost, high surface area nanoporous ruthenium catalysts by dealloying in acidic media.

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