Nickel catalyst with atomically-thin meshed cobalt coating for improved durability in dry reforming of methane

Abstract

Nickel nanoparticles are effective catalysts for the dry reforming of methane (DRM) in terms of catalytic activity and cost. Yet when applied to DRM reaction under realistic conditions, it is of great challenge overcoming the related durability problems due to sintering and coke deposition. Atomically thin meshed-like Co coating catalytic structure is designed and fabricated to decorate Ni nanoparticles via atomic layer deposition. The coating structure improves the catalytic activity and effectively eliminates carbon deposition for the DRM reaction. Optimized catalytic performance is achieved by fine tuning the density of Co coating on nickel particles. The meshed coating structure partitions the Ni surface to prevent continuous carbon nanotubes network formation. The Co component helps stabilizing the metallic phase of Ni in the DRM reaction. The Co-Ni interfaces created are beneficial for reducing carbon intermediates CHx formation and accelerate carbon removal. The amount of carbon formation can be reduced to 2.9%, which is a significant improvement (reduction over 2 to 6 times) compared with a series of state-of-the-art research reports (8–23%) on Ni-based catalysts in the severe coking temperature range (around 650 °C). The Co coating layer provides physical confinement and also improves the thermal stability of Ni nanoparticles from sintering and agglomeration up to 850 °C.