A direct CH4 metal-supported solid oxide fuel cell with an engineered Ni/Gd-doped CeO2 anode containing Ni and MnO nanoparticles

Abstract NiMn2O4 (NMO) coated Gd-doped CeO2 (GDC) and NiO powders are prepared by a hydrothermal method for the anode of a metal (Ni-10 at.% Fe)-supported solid oxide fuel cell fueled by wet CH4 (3 vol.% H2O). NMO remains on NiO but dissolves into GDC at 1400 °C. Upon reduction in H2 at 700 °C for 2 h, Ni nanoparticles exsolve on the doped-CeO2 (DCO) substrate (DCO@Ni), while MnO nanoparticles form on Ni (Ni@MnO). DCO@Ni demonstrates high catalytic activity for reforming wet CH4 and high resistance to carbon deposition with a yield of H2 increasing from 11 (500 °C) to 33 (700 °C) ml min−1 and remaining around 25 ml min−1 at 600 °C for 30 h. The metal-supported single-cell with a Ni@MnO-DCO@Ni anode shows high initial and durable electrochemical performance with a maximum power density increasing from 160 (500 °C) to 720 (700 °C) mW cm−2 and a cell voltage remaining above 0.55 V at 600 °C for 200 h under 400 mA cm−2 and 20 ml min−1. Such high performance is ascribed to the metal support with low ohmic resistance and the engineered anode with high catalytic activity and enhanced resistance to carbon deposition.