Catalyst gold/iron

Hodge NA, Kiely CJ, Whyman R, Siddiqui MRH, Hutchings GJ, Pankhurst QA, Wagner FE, Rajaram RR, Golunski SE (2002) Microstructural comparison of calcined and uncalcined gold/iron-oxide catalysts for low-temperature CO oxidation. Catal Today 72 133... 

Wu K-C, Tung Y-L, Chen Y-L, Chen Y-W (2004) Catalytic oxidation of carbon monoxide over gold/iron hydroxide catalyst at ambient conditions. Appl Catal B Environ 53 111... 

F.E. Wagner, S. Galvagno, C. Milone, A.M. Visco, L. Stievano and S. Calogero, MSssbauer characterisation of gold/iron oxide catalysts, J. Chem. Soc.-Faraday Trans., 93(18), 3403-3409, 1997. 

Albonetti, S., BonelU, R., Delaigle, R., et al. (2010). Catalytic Combustion of Toluene over Cluster-derived Gold/Iron Catalysts, Appl. Catal. A Gen., 372, pp. 138-146. 

Minico, S., Scire, S., CrisafnUi, C., and Galvagno, S. Inflnence of catalyst pretreatments on volatile organic componnds oxidation over gold/iron oxide. Appl. Catal. B Environ. 2001, 34, 277-285. 

Wang, C.-T. and Ro, S.-H. (2006) Surfece nature of nanoparticle gold/iron oxide aerogel catalysts. J. Non-Cryst. Solids,... 

A novel preparation method was developed for the preparation of iron and gold/iron supported eatalysts using metaUic carbonyl clusters as precursors of highly dispersed nanoparticles over Ti02 and Ce02. A series of catalysts with different metal loadings were prepared and tested in the complete oxidation of methanol and the preferential oxidation of CO in the presence of H2 (PROX) as model reactions. The characterization by BET, XRD, TEM, H2-TPR, ICP-AES and XPS spothghts the interaction between Au and Fe and their influence on the catalytic activity. 

Carbon monoxide oxidation over catalysts prepared by in situ activation of amorphous gold-silver-zirconium and gold-iron-zirconium alloys, A. Baiker, M. Maciejewski, S. Taghaferri, and P. Hug, J. Catal, 1995, 151, 407. 

Why Do We Need to Know This Material The d-block metals are the workhorse elements of the periodic table. Iron and copper helped civilization rise from the Stone Age and are still our most important industrial metals. Other members of the block include the metals of new technologies, such as titanium for the aerospace industry and vanadium for catalysts in the petrochemical industry. The precious metals—silver, platinum, and gold—are prized as much for their appearance, rarity, and durability as for their usefulness. Compounds of d-block metals give color to paint, turn sunlight into electricity, serve as powerful oxidizing agents, and form the basis of some cancer treatments. 

Mossbauer spectroscopy is a specialist characterization tool in catalysis. Nevertheless, it has yielded essential information on a number of important catalysts, such as the iron catalyst for ammonia and Fischer-Tropsch synthesis, as well as the CoMoS hydrotreating catalyst. Mossbauer spectroscopy provides the oxidation state, the internal magnetic field, and the lattice symmetry of a limited number of elements such as iron, cobalt, tin, iridium, ruthenium, antimony, platinum and gold, and can be applied in situ. 

The initial rates of CO oxidation were determined on the samples treated in different ways. The reactivity of the samples investigated in the preliminary experiments decreases in the sequence of Au/FeO c/SiO (/Si(l 0 0) > FeO / SiO,/Si(10 0)>Au/Si02/Si(100)>Si(100). The Au/ Fe0 c/Si02/Si(l 0 0) catalyst has the highest initial activity. The results along with XPS and TEM data demonstrate that the interaction of gold nanoparticles and iron oxide tends to stabilize the metal character of gold and due to this stabilization, the Au/FeO catalyst has enhanced activity in the CO oxidation. 

Three series of Au nanoparticles on oxidic iron catalysts were prepared by coprecipitation, characterized by Au Mossbauer spectroscopy, and tested for their catalytic activity in the room-temperature oxidation of CO. Evidence was found that the most active catalyst comprises a combination of a noncrys-taUine and possibly hydrated gold oxyhydroxide, AUOOH XH2O, and poorly crystalhzed ferrihydrate, FeH0g-4H20 [421]. This work represents the first study to positively identify gold oxyhydroxide as an active phase for CO oxidation. Later, it was confirmed that the activity in CO2 production is related with the presence of-OH species on the support [422]. 

Kozlova, A.P. Sugiyama, S. Kozlov, A.I. Asa-kura, K. Iwasawa.Y. (1998) Iron oxide supported gold catalysts derived from gold phosphor complex Au(PPh3) (NO3) State and structure of the support. J. Catalysis 176 426-438... 

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