Silica‐Enveloped 2D‐Sheet‐to‐Nanocrystals Conversion for Resilient Catalytic Dry Reforming of Methane

Abstract Here, lamellar confinement strategy is introduced for “sheet‐to‐nanocrystals (NCs)” conversion within a 2D‐SiO₂ envelope, which constructs a catalytic nanocartridge holding a platoon of isolated and in‐plane‐aligned ultrasmall Ni‐NCs, performing as a robust and coking‐resistant catalytic system for dry reforming of methane. Overcoming the problem of unavoidable bulk crystal growth from multiple sheets‐stack or sheet‐on‐open‐support, silica bilayer‐encasing tightly clamps the atomic‐thin Ni(OH)₂‐nanosheet during thermal conversion and further hinders the migratory fusion of the resultant Ni‐NCs. Upon heating‐cooling cycle, the flapping silica envelope clutches the Ni‐NCs like “eggs in a carton,” subsequently, ensuring their thermal stability. Owing to the unique 2D‐enveloped rigid architecture, Ni‐NCs can circumvent sintering and coke deposition while tolerating the high temperatures (>700 °C) for long operation (>100 h), affording high conversions to syngas.