Toward highly efficient in situ dry reforming of H2S contaminated methane in solid oxide fuel cells via incorporating a coke/sulfur resistant bimetallic catalyst layer

Abstract

The escalating global warming effects are a reason for immediate measures to reduce the level of greenhouse gases. In this context, dry reforming of methane (DRM), an old yet both scientifically and industrially important process, is making a comeback in contributing to the utilization of CO₂. However, catalyst deactivation (sulfur poisoning and coke formation) and the associated high energy consumption remain technological hurdles to its practical implementation. Here we demonstrated that dry reforming of H₂S-containing CH₄ can be efficiently conducted in conventional solid oxide fuel cells via incorporating a coke/sulfur resistant catalyst layer. The add-on layer, composed of tailored Ce_0.8Zr_0.2O₂ supported NiCu nanoclusters, demonstrated outstanding in situ reforming activity while possessing reasonable coke/sulfur resistance. At 800 °C and in a 50 ppm H₂S containing CH₄–CO₂ mixture, the cell had a maximum power density of 1.05 W cm⁻², a value high enough for practical application. Through H₂ selective oxidation, the energy required for DRM was partially compensated for and the produced water greatly suppressed the carbon deposition. This study offers a new dimension in cogenerating CO₂-derived synthesis gas and electrical power in the context of increasing interests in efficient utilization of H₂S-containing CH₄ and CO₂.