Copper nanoparticles within the pore channels of selectively grafted mesoporous silica SBA-15 were synthesized. Silanols on the external surface of as-SBA-15 were first capped by -Si(CH(3))(3) groups. After the removal of the template of capped SBA-15 by calcination, silanols on the internal surface of SBA-15 were modified by 3-aminopropyltrimethoxysilane (APTMS), and then formaldehyde was grafted to the amino groups of APTMS and with Cu(NH(3))(4)(NO(3)). The support and catalyst were characterized by X-ray diffraction (XRD), Barett-Joyner-Halenda (BJH) pore-size distribution, Brunauer-Emmett-Teller (BET) surface area, Fourier transform infrared spectroscopy (FT-IR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and adsorption calorimetry. The initial conversion follows the trend in size: 52% at pore size 6.0 for this catalyst at 343 K.