Novel BaO-decorated carbon-tolerant Ni-YSZ anode fabricated by an efficient phase inversion-impregnation approach

Abstract

In this study, an efficient phase inversion-impregnation approach is developed for fabricating BaO-decorated Ni-8 mol% yttria-stabilized zirconia (YSZ) anode-supported tubular solid oxide fuel cells (SOFCs) toward anti-coking. This technique involves a simple phase-inversion process, along with the saturated barium nitrate solution as coagulation bath. Experimental results show that BaO nanoislands with particle size of less than 100 nm have been successfully and uniformly introduced inside the Ni-YSZ anode. The corresponding peak power densities are determined to be 0.30 W cm−2 and 0.22 W cm−2 at 800 °C in wet hydrogen and methane fuel, respectively. The long-term stability in methane fuel with the BaO-decorated anode is significantly improved with respect to the pristine one. Density functional theory (DFT) calculations suggest that the loading of BaO nanoislands can efficiently capture and dissociate the H2O molecules to generate OH, which subsequently serves as effective carbon elimination medium. The OH diffusion from BaO to BaO/Ni interface coupling with the formation of COH is the key step involved in the carbon elimination mechanism. The as-proposed phase inversion-impregnation approach exhibits advantage in time and cost savings compared to traditional impregnation methods, providing a new route for fabricating anti-coking SOFC anodes.