Degussa method

Scheme 4.1 Chemical synthesis of 1,3-propanediol by Degussa method starting from...

Cyanide spills can also be neutralized with peroxide by the Degussa method, in which the pH is maintained above 9 (between 9.0 and 10.5) to avoid formation of toxic NCI3, nitrogen trichloride. The Degussa method is shown below ... 

The second process for large-scale synthesis, also applicable for small-scale use, is the Degussa method whereby methane and ammonia react to form HCN with an external heat source (external methane combustion) ... 

Finally, two major industrial applications of nanocatalysts should be mentioned that are currently in the transition from basic research to industrial scale-up. Headwaters NanoKinetix and Degussa have developed and patented [412-A15] a direct synthesis method for the... 

A 0.5 wt% Pt/Ti02 catalyst was prepared by the photodeposition method. A 100 mg Ti02 (Aeroxide P25S Degussa, 50 m /g, approximately 70% anatase and 30% mtile) were suspended in 30 mL aqueous solution with 1.4 mg chloroplatinic acid... 

The pyrogenic flame hydrolyzed silica Aerosil 200, a commercial product from Degussa, was used as a dispersion in doubly distilled water (1). The precipitated silica was prepared by hydrolysis of orthosilicic acid tetraethylester in ammoniacal solution according to the method of Stober, Fink and Bohn (11). The prepared suspension was purified by repeated centrifugation, separation from solvent and redispersion of the sediment in fresh water. Finally, the water was evaporated and the wet silica dried at 150°C for about half an hour. 

The process of Degussa, now owned by Dupont, uses the conventional preparation method starting from acrolein which is obtained by catalytic oxidation... 

We are developing a new method for preparing heterogeneous catalysts utilizing polyamidoamine (PAMAM) dendrimers to template metal nanoparticles. (1) In this study, generation 4 PAMAM dendrimers were used to template Pt or Au Dendrimer Encapsulated Nanoparticles (DENs) in solution. For Au nanoparticles prepared by this route, particle sizes and distributions are particularly small and narrow, with average sizes of 1.3 + 0.3 nm.(2) For Pt DENs, particle sizes were around 2 nm.(3) The DENs were deposited onto silica and Degussa P-25 titania, and conditions for dendrimer removal were examined. 

Several methods of metal removal from process solutions exist. Some of these approaches include crystallization, distillation and extraction. However, these methods can be very time-consuming and often result in loss of some valuable product. To overcome these shortcomings, Degussa has developed Deloxan Metal Scavengers as an attractive option to solve problems associated with transition metal contamination of process solutions. [3, 4, 5] Two resins are commercially available. Deloxan THP 11 (1) is a thiourea functionalized, macroporous, organofunctional polysiloxane while Deloxan MP (2) is mercapto functionalized. 

TiOj coated fabric filters were prepared in a one-step process by the solvothermal method, and their properties were compared with those electrosprayed with Degussa P25. Filters coated with TiO nanoparticles prepared by the solvothermal method were superior to the commercial TiO powder in terms of particle size and homogeneity. A significant amount of bactericidal activity towards E. coli was successfully implanted into fabric filters by dip coating a solvothermally prepared TiO dispersion. 

The Al-containing Ti-beta sample, TB-1, was synthesized according to the methods proposed by Camblor et al. [4], Aerosil 200 (Degussa), titanium ethoxide. tetraethylammonium (TEAOH 40 wt%, Alfa), and aluminum nitrate nonahydrate were used as reagents. The ratios Si/Ti and Si/Al were adjusted as needed. 

Two types of catalysts were used in this study pure TiO (Degussa,P-25), previously calcined in air at 500-C for 24 h, and iron-doped TiOj. The iron--doped TiO catalysts, Fe/TiO used in the present study (iron contents 0.5 wt % or 5 wt %, both calcined at 500 C, 24 h), involves the dispersion of iron (as Fe +) in the TiO matrix the preparation of these catalysts, by the wet impreg nation method, as well as the characterization, have been previously described (ref.8). Distilled toluene was reagent grade. 

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