Air plasma sprayed Cu–Co–GDC anode coatings with various Co loadings

In this work, Cu–Co–gadolinia doped ceria (GDC) anode coatings were fabricated by atmospheric plasma spraying (APS) of agglomerated CuO, Co3O4, and GDC feedstock powders. Screening tests were conducted to identify the effect of plasma gas composition on the coating phases, microstructure, and absolute deposition efficiency of each material. Based on screening tests, optimized plasma energy conditions were identified. Using the absolute deposition efficiency, feedstock powder mixing ratios were determined to produce anode coatings with Cu–Co weight ratios of Cu(100)–Co(0), Cu(90)–Co(10), Cu(70)–Co(30), and Cu(50)–Co(50), with 40 vol% of metal phases in the coating and 60 vol% of GDC. After reduction of the coatings, porosity and gas permeability were determined. Finally, carbon deposition behavior was examined by measuring the weight gain of the coatings after exposure to CH4 at 700 °C for 3 h. The coatings demonstrated good resistance to carbon deposition.

► Plasma spraying was used to manufacture Cu–Co–GDC coatings for use in SOFC anodes. ► Coating composition was set using the absolute deposition efficiencies. ► Co does not seem to have a role in increasing coating porosity. ► XRD patterns indicated possible interdiffusion of Co and Cu. ► The coatings demonstrated stability against carbon formation comparable to that in literature.