Mutual dissolution and exsolution enables superior coking resistance of cermet fuel electrode

Abstract

The matured infrastructures for hydrocarbons storage and transportation makes the reversible conversion between carbon-contained fuels and electricity a highly promising way for the utilization of renewable energy towards a sustainable carbon–neutral society. Reversible solid oxide cells may play a significant role considering their high efficiency, fast reaction kinetics, and easy scale up. However, the nickel-based electrodes face a big challenge in practical use due to easy coking. Here, we report conventional nickel-based cermet can be transferred into an efficient fuel electrode with superior coking resistance and improved activity by simply introducing a mutual dissolution-exsolution strategy. The key is the application of ultrafine nickel oxide as raw material, and their mutual dissolution is realized during calcination and sintering, forming a composite with nickel nanoparticles modified yttrium-stabilized zirconia (YSZ) and zirconia nanoparticles/thin films decorated bulk nickel during the subsequent reduction process. The exsolved nickel nanoparticles provide excellent electrocatalytic activity while the bulk nickel is protected from coke formation by the exsolved nano zirconia nanoparticles/film. As a result, favorable activity and excellent stability for the direct utilization of hydrocarbon fuels for power generation and carbon dioxide electrolysis is realized, making it highly promising for practical application.