VOC and CVOC Abatement over Novel Pt/Fiberglass Catalysts
Тезисы доклада (Meeting Abstracts),
247th ACS National Meeting & Exposition
16-20 мар. 2014
||Abstracts of Papers, 247th ACS National Meeting & Exposition, Dallas, TX, United States, March 16-20, 2014
American Chemical Society. Washington, D. C.2014.
Boreskov Institute of Catalysis, Novosibirsk, Russia 630090
Nonporous fiberglass (FG) textile materials are practically unknown in catalysis in spite of their obvious advantadges, like high thermal stability, chem. resistance, improved hydrodynamics. But their main advantage is the capability to stabilize in the subsurface layers of glass the highly dispersed metal species which are active in many reactions. Here, we present the data on structure of Zr-silicate glass, features of the Pt or Pd/FG catalysts prepn. and their characterization by means of NMR, FTIR, STEM, XPS, UV-Vis DRS. Com. FG material (10% Zr) consists of elementary 7 μm fibers which are twisted into 1 mm threads, which in turn, are woven into fabrics with BET surface 0,5 m2/g which is close to geometrical one. The glass structure is characterized by alternating chains of randomly bound silicon-oxygen tetrahedra (dense spaces) with low d. spaces where hydroxyl groups (Si-OH) are located. Zr-silicate glass has a framework structure where four Zr+4 cations linked by a few SiO4tetrahedra forms unit framework. Pt(II) ammonia complexes were introduced into the bulk of fiber via ion exchange with strong hydroxyl protons of the glass, then Pt species were decompd. at elevated temps. with formation of the small metal clusters (ca.1 nm) located in the upper layers of glassmatrix (10-20 nm). In spite of very low noble metal content (0,02% wt.) the prepd. catalysts showed high performance in both deep oxidn. of hydrocarbons and destruction of polychlorinated hydrocarbons, including dioxins. The good correlation between activity and amt. of the highly dispersed Pt indicates clearly that namely small Pt clusters are responsible for the activity. High performance of this catalyst was successfully confirmed on industrial level in the abatement of waste gases from synthetic rubber plant, when the catalyst showed stable purifn. efficiency 99%+ for more than 4 years of the continuous operation.