Metal impregnated activated carbon

Some natural gases have also been found to contain mercury, which is a reformer catalyst poison when present in sufftciendy large amounts. Activated carbon beds impregnated with sulfur have been found to be effective in removing this metal. 

Activated carbon when used can work as a reducing agent, as a catalyst, and as an adsorbent. When used as a catalyst, the activated carbons are impregnated with metals that can reduce the temperature required for the reduction of the oxides of nitrogen to nitrogen. The reduction in temperature could be 600 to 700°C for an imcatalyzed reaction to as low as 300°C for a catalyzed reaction. Copper is one of the metals which, when impregnated on the surface of carbon, can significantly... 

Nitrogen adsorption experiments showed a typical t)q5e I isotherm for activated carbon catalysts. For iron impregnated catalysts the specific surface area decreased fix>m 1088 m /g (0.5 wt% Fe ) to 1020 m /g (5.0 wt% Fe). No agglomerization of metal tin or tin oxide was observed from the SEM image of 5Fe-0.5Sn/AC catalyst (Fig. 1). In Fig. 2 iron oxides on the catalyst surface can be seen from the X-Ray diffractions. The peaks of tin or tin oxide cannot be investigated because the quantity of loaded tin is very small and the dispersion of tin particle is high on the support surface. 

In another study, it was shown that the activity of hydrochlorination catalysts made by impregnation of activated carbon with tetrachloroaureate is due to the adsorption of [AuCy anions on the activated carbon [423]. Similar studies, dealing with the adsorption of aurocyanide, [Au(CN)2] , onto activated carbon, have revealed that aurocyanide does not convert to metallic gold up to temperature of about 240°C [424, 425]... 

Before preparing these carbon-supported Pt-based catalysts, a support pretreatment toward granular activated carbon with an aqueous solution of NaOH (pH 14) was carried out by immersing for 24 h to promote the anion exchange between the ligand chloride of impregnated metal precursers (K2PtCl4) and the aqueous hydroxide ion (OH ) inside the micropores of the activated carbon [33]. 

The feasibility of carbon-supported nickel-based catalysts as the alternative to the platinum catalyst is studied in this chapter. Carbon-supported nickel (Ni/C, 10 wt-metal% [12]), ruthenium (Ru/C, 10 wt-metal% [12]), and nickel-ruthenium composite (Ni-Ru/C, 10 wt-metal%, mixed molar ratio of Ni/Ru 0.25,1,4, 8, and 16 [12]) catalysts were prepared similarly by the impregnation method. Granular powders of the activated carbon without the base pretreatment were stirred with the NiCl2, RuC13, and NiCl2-RuCl3 aqueous solutions at room temperature for 24 h, respectively. Reduction and washing were carried out in the same way as done for the Pt/C catalyst. Finally, these nickel-based catalysts were evacuated at 70°C for 10 h. 

BMS A process for removing mercury from the effluent from the Castner-Kellner process. Chlorine is used to oxidize metallic mercury to the mercuric ion, and this is then adsorbed on activated carbon impregnated with proprietary sulfur compounds. Developed by Billingsfors Bruks, Sweden. 

Up to now, a variety of non-zeolite/polymer mixed-matrix membranes have been developed comprising either nonporous or porous non-zeolitic materials as the dispersed phase in the continuous polymer phase. For example, non-porous and porous silica nanoparticles, alumina, activated carbon, poly(ethylene glycol) impregnated activated carbon, carbon molecular sieves, Ti02 nanoparticles, layered materials, metal-organic frameworks and mesoporous molecular sieves have been studied as the dispersed non-zeolitic materials in the mixed-matrix membranes in the literature [23-35]. This chapter does not focus on these non-zeoUte/polymer mixed-matrix membranes. Instead we describe recent progress in molecular sieve/ polymer mixed-matrix membranes, as much of the research conducted to date on mixed-matrix membranes has focused on the combination of a dispersed zeolite phase with an easily processed continuous polymer matrix. The molecular sieve/ polymer mixed-matrix membranes covered in this chapter include zeolite/polymer and non-zeolitic molecular sieve/polymer mixed-matrix membranes, such as alu-minophosphate molecular sieve (AlPO)/polymer and silicoaluminophosphate molecular sieve (SAPO)/polymer mixed-matrix membranes. 

Catalysts were prepared by impregnating a commercially available granular activated carbon (Takeda Shirasagi C, charcoal base, activated with steam, specific surface area 1200 m /g, particle size 20-40 mesh) and other commercially available ones with metal nitrates and chlorides in aqueous solution. The catalysts were dried in air at 120 for 24 h and then reduced in flowing hydrogen at 400 for 3 h. The metal content in the catalyst was 2.5 wt%... 

The catalyst was prepared by impregnation of the powdered activated carbon support, Norit SX Ultra, (surface area 1200 m g ) with sufficient palladium nitrate to produce a metal loading of 3 %. The resulting suspension was dried and calcined at 423 K for 3 hours. The dispersion of the catalyst was... 

Rajakovic, L.V. (1992) The sorption of arsenic onto activated carbon impregnated with metallic silver and copper. Separation Science and Technology, 27(11), 1423-33. 

Reagent impregnated resins can be used as trapping sorbents for the preconcentration of heavy metals.1 These materials can be used in the same way as activated carbons. 

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