A novel Boudouard reaction catalyst derived from strontium slag for enhanced performance of direct carbon solid oxide fuel cells

Abstract

Direct carbon solid oxide fuel cells (DC-SOFCs) are recognized as an efficient energy conversion device. With regard to their working principle, the reverse Boudouard reaction rate is the crucial factor influencing cell performance. In this work, a new-type catalyst derived from industrial strontium slag (SS) was first introduced into DC-SOFCs to promote the reverse Boudouard reaction and power output. The physicochemical properties of SS and strontium slag-derived catalyst (SSC) were characterized by SEM/EDS, BET, XRD and XRF techniques in detail. The advantages of SS and SSC were reflected in the enhanced DC-SOFC performance and high fuel utilization. The single cell powered by SSC-loaded carbon exhibited the best output of 248 mW cm−2 at 850 °C. This result was comparable to the 274 mW cm−2 output of a hydrogen-fueled SOFC due to the superior catalytic activity of metallic catalysts toward carbon gasification. The superiority of the SSC was also observed in the durable operation of the corresponding DC-SOFCs, which lasted for 32.0 h at 50 mA with the fuel utilization of 25.6%. This work provides a new channel for green and efficient utilization of strontium slag and other industrial residues, and a novel option to the development of energy conversion technology.