Hydrogenation Processes and VOC Abatement over Novel Pd and Pt Fiberglass Catalysts
Тезисы доклада (Meeting Abstracts),
246th ACS National Meeting & Exposition
08-12 сент. 2013
||Abstracts of Papers, 246th ACS National Meeting & Exposition, Indianapolis, IN, United States, September 8-12, 2013
American Chemical Society. Washington, D. C.2013.
Институт катализа им. Г.К. Борескова СО РАН
Non-porous fiber glass (FG) textile materials of silicate origin are manufactured in industry and widely used as perfect heat and elec. insulators. At the same time, these materials are less known in catalysis despite their obvious advantages such as high thermal stability and improved hydrodynamics. The capability of glass to stabilize the highly dispersed metals (clusters) in the bulk is responsible for excellent performance of FG based catalysts in many reactions in spite of extremely low noble metal content (0.01-0.02% weight).Here, we present new data on the mol. structure of glass, features of the Pd/FG and Pt/FG catalysts preparation, their characterization by means of XPS, UV-Vis DRS, HRTEM, NMR, FTIR, etc., as well as testing in selective hydrogenation of acetylene in ethylene feedstock and in VOC and CVOC abatement, including dioxins. It was shown clearly that Pd and Pt are actually stabilized as very small metal clusters (≤ 1 nm) in the bulk of glass at a depth of tens nm. Nevertheless, the reaction rate is not limited by diffusion of reactants in the bulk of glassmatrix. The ability of fiberglass materials to act as a specific membrane permeable to polar and polarizable mols., like acetylene, favores also the high performance of Pd/FG catalyst in the selective hydrogenation of acetylene. This effect is most pronounced at high acetylene conversion (99%+) when the reaction selectivity remains still high (ca. 60%) and exceeds that of com. mono-, and bimetallic Pd-based catalysts. Similarly, Pt/FG catalysts were much more active in deep oxidation of hydrocarbons and oxidative destruction of chlorinated hydrocarbons compared with com. ones. SSITKA studies with use of double labeled 13C2H2 and 18O2 mols. allowed us to elucidate the features of both reaction mechanisms that are based on the glass mol. structure, its electrophys. properties and high noble metal dispersion.