Extraordinary Catalytic Performance of Nickel Half-Metal Clusters for Light-Driven Dry Reforming of Methane

摘要

Global warming and the energy shortage due to the burning of fossil fuels are two major challenges. A strategy of light-driven catalytic dry reforming of methane (DRM) using inexhaustible solar energy has provided an effective approach to tackle these challenges. Loaded metallic Ni nanoparticles have been identified as promising catalysts as alternatives to noble metals for DRM. However, they suffer from quick deactivation caused by severe coking due to thermodynamically inevitable side-reactions. Herein, a unique nickel half-metal catalyst of monolayer nickel clusters stabilized by alumina is reported, with 100 atomic utilization efficiency and extraordinary catalytic performance for light-driven DRM, dramatically different from its counterpart of conventional metallic Ni nanoparticles. It has extremely high specific H2 and CO production rates of 8572.96 and 9614.26 mmol min~(?1) gNi~(?1), more than one order of magnitude higher than those of Ni nanoparticles. No detectable coke is formed due to the alteration of kinetic processes for DRM, resulting in the inhibition of coke deposition. It is discovered that light not only significantly enhances catalytic activity, but also enables quick thermocatalytic deactivation to be durable due to the oxidation of carbon species and the desorption of strongly adsorbed CO_2 and CO being dramatically promoted by light.