Platinum Group Metal Catalysts

Olefins add anhydrous acetic acid to give esters, usually of secondary or tertiary alcohols propjiene [115-07-1] yields isopropyl acetate [108-21-4], isobutjiene [115-11-7] gives tert-huty acetate [540-88-5]. Minute amounts of water inhibit the reaction. Unsaturated esters can be prepared by a combined oxidative esterification over a platinum group metal catalyst. Eor example, ethylene-air-acetic acid passed over a palladium—Hthium acetate catalyst yields vinyl acetate. 

Another synthesis of pyrogaHol is hydrolysis of cyclohexane-l,2,3-trione-l,3-dioxime derived from cyclohexanone and sodium nitrite (16). The dehydrogenation of cyclohexane-1,2,3-triol over platinum-group metal catalysts has been reported (17) (see Platinum-GROUP metals). Other catalysts, such as nickel, rhenium, and silver, have also been claimed for this reaction (18). 

Supported gold catalysts are, in general, less active than platinum group metal catalysts in the complete oxidation of hydrocarbons however, by choosing... 

Burch, R., Breen, J.P. and Meunier, F.C. (2002) A review of the selective reduction of NO, with hydrocarbons under lean-burn conditions with non-zeolitic oxides and platinum group metal catalysts, Appl. Catal. B, 39, 283. 

Aqueous two-phase hydrogenations are dominated by platinum group metal catalysts containing water-soluble tertiary phosphine ligands. The extremely stable and versatile N-heterocyclic carbene complexes attracted only limited interest, despite the fact that such complexes were described in the literature [62-65]. Recently, it was reported that the water-soluble [RuXY(l-butyl-3-methylimi-dazol-2-ylidene) ( 76-p-cymene)]n+ (X=Ch, H20 Y = C1-, H20, pta) complexes preferentially hydrogenated cinnamaldehyde and benzylideneacetone at the C = C double bond (Scheme 38.5) with TOF values of 30 to 60 h 1 in water substrate biphasic mixtures (80 °C, lObar H2) [66]. 

IV-Aldehydes, platinum-group metal catalysts and, 19 621 Aldehydic floral perfumes, 18 357 Aldehydic odor, 3 227t Aldehydo sugars, 4 699 Alder, biomass production by, 17 298-299 Aldgamycins, 15 297t, 298 Aldicarb, 3 777, 778... 

See also Potassium-sodium (NaK) alloys physical properties of, 20 604t Naked license, 25 265 AT-aldehydes, platinum-group metal catalysts and, 19 621 Naled, 4 358t... 

Nitric acid synthesis, platinum-group metal catalysts in, 19 621 Nitric acid wet spinning process, 11 189 Nitric oxide (NO), 13 791-792. See also Nitrogen oxides (NOJ affinity for ruthenium, 19 638—639 air pollutant, 1 789, 796 cardioprotection role, 5 188 catalyst poison, 5 257t chemistry of, 13 443—444 control of, 26 691—692 effect on ozone depletion, 17 785 mechanism of action in muscle cells, 5 109, 112-113 oxidation of, 17 181 in photochemical smog, 1 789, 790 reduction with catalytic aerogels, l 763t, 764... 

Terephthalic acid manufacture, platinum-group metal catalysts in, 29 622 Terephthalic acid PET bottle resin process, 20 48-50... 

Aspnes DE, Heller A (1983) Photoelectrochemical hydrogen evolution and water- photolyzing semiconductor suspensions Properties of platinum group metal catalyst emiconductor contacts in air and in hydrogen. J Phys Chem 87 4919-4929... 

Heller A, Aharon-Shalom E, Bonner WA, Miller B. (1982) Hydrogen-evolving semiconductor photocathodes. Nature of the junction and function of the platinum group metal catalyst. J Am Chem Soc 104 6942-6948... 

Xylose and fructose. Xylose can be hydrogenated into xylitol (Scheme 13). This reaction was reported using hydrogenation catalysts such as Raney nickel as well as platinum group metal catalysts. ... 

Raney nickel, copper and platinum group metal catalysts have also been used as catalysts for transforming fructose into mannitol via catalytic hydrogenation (Scheme 14) 197-199,203,204 supported on carbon... 

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