Enhanced Nickel-Catalyzed Methanation Confined under Hexagonal Boron Nitride Shells

Encapsulation of metal nanoparticles with porous oxide shells is a successful strategy to design catalysts with high catalytic performance. We suggest an alternative route to cover metal nanoparticles with two-dimensional (2D) material shells such as hexagonal boron nitride (h-BN), in which active metal components are stabilized by the outer shells and meanwhile catalytic reactions occur at interfaces between cores and shells through feasible intercalation of the 2D material covers. As an illustration, Ni nanoparticles encapsulated with few-layer h-BN shells were constructed and applied in syngas methanation. Ni@h-BN core-shell nanocatalysts exhibit enhanced methanation activity, higher resistance to particle sintering, and suppressed carbon deposition and Ni loss in reactions. Surface science studies in h-BN/Ni(111) model systems and chemisorption data confirm the occurrence of methanation reactions on Ni surfaces under h-BN cover. The confinement effect of h-BN shells improves Ni-catalyzed reaction activity and Ni catalyst stability.