In this work, a nanoreactor combining layers of facile traditional two-dimensional (2D) material, hexagonal boron nitride (h-BN, which often called the white graphene) with Pt/Al2O3 catalyst was designed to exhibit higher stability, activity, and selectivity in automobile exhaust treatment. Characterization revealed that h-BN does coat on the surface of platinum and forms a distinct Pt@h-BN/Al2O3 core-shell nanostructure. This as-prepared catalyst possesses good thermal stability and selectivity, because of the excellent high-temperature tolerance and the multidefected structure of the h-BN shell; that is, small molecules such as CO and O-2 can easily intercalate into the nanoreactor, while large molecules such as propylene are blocked out. Meanwhile, the intercalated reactants can achieve the conversion of CO to CO2 faster (Delta T-100 = 20 degrees C) with the confinement effect. The study indicates that constructing a nanoscale confined environment with two-dimensional (2D) coating can enhance the performance simultaneously provide a good example for designing nanostructured catalysts with multifaceted of the catalyst in multiple aspects and improvement.