Reactivity Study of Platinum Nanoparticles and Nanowires Inside the Channels of Mesoporous Silica

Pt metal nanowires and nanoparticles were prepared using mesoporous silica as the template. Mesoporous silica with straight 1-dimensional, tortuous 1-dimensional and 3-dimensional channels was used. The experimental techniques included CO oxidation, Chemisorption, XRD, and STEM. CO oxidation and chemisorption provided the data to calculate the intrinsic reactivity, known as turn over frequency (TOF). Powder XRD was used to measure line broadening. The FWHM of the XRD line broadening was used with the Scherrer formula to determine Pt metal crystallite size. STEM images permitted for the measurement of the particle diameters, and the determination of morphology. Two commercially available reference samples were used to provide a benchmark for comparison, namely Pt on alumina and Pt on silica. The resulting TOF of these reference catalysts were identical, confirming that the CO oxidation reaction is structure insensitive.