Notably, when the 71 Ga NMR was recorded on 15 N-py/Ga@SiO2, (Figure ); the resulting spectra display significantly narrower lineshape (i.e. a lineshape dominated by a distribution with, on average, a lower CQ) than Ga@SiO2, suggesting that the adsorption of pyridine generates sites with more symmetric environment. The large change of the lineshape upon adsorption of py indicates that the observed Ga sites in Ga@SiO2 all reside at the surface (or very close to the surface) of the material.