Low-temperature dry reforming using high entropy alloy (Co-Fe-Ga-Ni-Zn)-cerium oxide (CeO2) hybrid nanostructure

Abstract

Utilization of carbon dioxide into green energy is one of the possible solutions to clean the environment. Among several possible methods, Dry reforming of methane (DRM) reaction is a simple and scalable way to convert large amounts of carbon dioxide into syngas (carbon monoxide and hydrogen). Stability is an issue in DRM as it is an endothermic reaction that results in carbon poisoning. Here, we demonstrate a high entropy alloy/CeO2 hybrid, an active and stable catalyst for DRM. The hybrid catalyst works at the lowest possible temperature i.e. 700 °C with a high H2/CO ratio along with high stability and conversion. The experimentally obtained H2/CO ratio matches with the theoretical calculated value which implies minimum side reactions. The hybrid catalyst outperforms the majority of the state of the art catalysts reported in literature. The DFT simulation and transient mechanistic study show that the hybrid catalyst results in an exothermic methane partial oxidation step due to the involvement of lattice oxygen. The current work can be utilized to clean the environment and produce highly energy-efficient fuel for green energy.