A direct-methane solid oxide fuel cell with a functionally engineered Ni–Fe metal support

Abstract

Reduced Ce0.9Ni0.1O2-δ consists of Ni nanoparticles and Ni-doped CeO2 (CNO), named (Ni@CNO) with Ni nanoparticles uniformly distributed on CNO substrate with high oxygen vacancy concentration and good water absorption capability. Thus Ni@CNO demonstrates moderate catalytic activity and high carbon deposition resistance during CH4 steam-reforming. When it is infiltrated into Ni0.9Fe0.1 (NF) metallic support for metal-supported solid oxide fuel cells (MS-SOFCs), forming a continuous coating, Ni@CNO offers CH4 steam-reforming activity additional to that of the NF support with increased H2/CH4 ratio (3.38 at 600 °C) in the reforming gas, enhanced carbon deposition resistance, and prolonged performance durability. With the Ni@CNO-infiltrated NF support (NFNC), Ni/Ce0.9Gd0.1O2-δ (Ni-GDC) function anode, GDC electrolyte, and La0.6Sr0.4Co0.2Fe0.8O3-δ/Ce0.9Gd0.1O2-δ (LSCF-GDC) cathode, the MS-SOFC cell directly fueled by wet CH4 (3 vol% H2O) exhibits a peak power density of 0.343 W cm−2 and the cell voltage durably maintains above 0.6 V at 400 mA cm−2 during a test of 280 h at 600 °C without noticeable carbon deposition in the support and the functional anode. Such performance is comparable to and higher than those reported, suggesting that NFNC is a promising option for direct-CH4 MS-SOFCs.