Exsolved Nanoparticles Decorated Double Perovskites as High-Performance Anodes for Direct-Ammonia Solid Oxide Fuel Cells

Abstract

Due to the high energy density, mature production technology, ease of storage and transportation, and the no carbon/sulfur nature of ammonia fuel, direct-ammonia solid oxide fuel cells (DA-SOFCs) have received rapidly increasing attention, showing distinct advantages over H2-fueled SOFCs and low-temperature fuel cells. However, DA-SOFCs with conventional Ni-based cermet anodes still suffer from several drawbacks, including serious sintering and inferior activity for ammonia decomposition, strongly limiting the large-scale applications. To tackle the above-mentioned issues, exsolved NiCo nanoparticles decorated double perovskite oxides are fabricated and employed as high-performance anodes for DA-SOFCs in this work. By optimizing the Ni doping amount in Sr2CoMo1−xNixO6−δ (x = 0.1, 0.2 and 0.3), the reduced Sr2CoMo0.8Ni0.2O6−δ (r-SCMN2) anode exhibits superb catalytic activity for ammonia cracking reaction and high anti-sintering capability. More specifically, the electrolyte-supported single cell with r-SCMN2 nanocomposite anode delivers superior power outputs and operational durability in ammonia fuel as compared with other r-SCMN anodes owing to the significantly promoted nanoparticle exsolution and stronger interaction between alloy nanoparticles and the support. In summary, this study presents an effective strategy for the design of efficient and stable nanocomposite anodes for DA-SOFCs.

Metal exsolution from perovskite-based anodes in solid oxide fuel cells

“…26 Experimental studies have confirmed that several metals can be precipitated from the perovskite lattice, including noble metals such as Pt, Pd, Rh, Ru and Ag, TMs such as Fe, Co, Ni and Cu, and their specific alloys. 27–33 This is attributed to the high reactivity of noble and TMs, making them ideal materials for the surface generation of metal NPs under reducing conditions. In particular, as nano-catalysts, B-site transition metal cations exhibit robust (electro)chemical catalytic activity and have found a wide range of applications in areas such as photo-/thermal catalysis and energy conversion.…”

Ru/Attapulgite as an Efficient and Low-Cost Ammonia Decomposition Catalyst

“…In the past decade or so, ammonia has emerged as a green energy carrier due to zero-carbon emissions upon decomposition and on-site utilization [2,3]. The most important merit of ammonia is that it can be liquified at mild conditions (at ambient temperature under about 10 atm or at −33 • C under atmospheric pressure), which makes its storage and transportation much easier than that of hydrogen [3][4][5]. Additionally, in terms of explosibility, ammonia is safer than hydrogen owing to its narrower flammability range [6].…”