Carbon monoxide as reducing agent

Carbinolamines, 87 Carbodiimides, 205-222 reaction with alcohols, 170 Carbon monoxide, as reducing agent, 336 a-Carbonyl azo compounds, 324, 326 Caro s add (permonosulfuric add), 408 oxidation with, 409 preparation of, 409 Chloramine T, 377 Chloroacetylenes 120-122 4-Chloro-l, 2-butadiene, 33 Chlorocyclohexenyl acetylene, 121 1 -Chloro-2-JV,N-diphenylaminoacetylene, 128-129... 

Wu JB, Gross A, Yang H (2011) Shape and composition-controlled platinum alloy nanoctys-tals using carbon monoxide as reducing agent. Ntmo Lett 11 798-802... 

Chemisorption measurements (Quantachrome Instruments, ChemBET 3000) were conducted in order to determine the metal (Co) dispersion. Therefore, the nanomaterial catalysts were reduced under a hydrogen flow (10% H2 in Ar) at 633 K for 3 h. The samples were then flushed with helium for another hour at the same temperature in order to remove the weakly adsorbed hydrogen. Chemisorption was carried out by applying a pulse-titration method with carbon monoxide as adsorbing agent at 77 K. The calculation of the dispersion is based on a molar adsorption stoichiometry of CO to Co of 1. 

The most commonly used reduction process for iron takes place in the blast furnace (Fig. 21.36). The raw materials required are concentrated iron ore, coke, and limestone (which serves as a flux to trap impurities). The furnace, which is approximately 25 feet in diameter, is charged from the top with a mixture of iron ore, coke, and limestone. A very strong blast (—350 mi/h) of hot air is injected at the bottom, where the oxygen reacts with the carbon in the coke to form carbon monoxide, the reducing agent for the iron. 

The action of carbon monoxide (CO) upon solutions of copper salts leads to the formation of cuprous CO complexes that have pronounced activity as reducing agents ... 

Indole derivatives might also be prepared by the palladium catalysed reductive heteroannulation of o-nitrostyrene derivatives. The bicyclic olefin, shown in 3.75. was converted to the indole derivative in good yield.94 The reaction, which was run under forcing conditions utilises carbon monoxide as the reducing agent. 

In Eq. 15.7 the carbon monoxide itself is acting as reducing agent. 

Some species are also able to utilize formate or formaldehyde as reducing agents.435 These compounds are oxidized to C02, the reducing equivalents formed being used to reduce C02 to methane. Carbon monoxide can also be converted to C02. 

Here we consider carbon monoxide as a chemical reducing agent, with the oxidation product being C02 in all cases. Carbon monoxide may act as a reductant in three different ways (1) as a direct oxygen atom acceptor (2) as a two-electron reductant with water as the source of oxygen and (3) as an indirect reductant in which the reducing power of CO is used to make H2 which then carries out the desired reduction. The three ways are shown schematically as (24)-(26) (in (24) [O] represents an oxide source). Equation... 

The carbon is the reducing agent as it takes away the oxygen from the iron ore and itself is oxidized to carbon monoxide. The iron oxide has been reduced to iron. 

Zinc production follows a similar path to the iron and lead processes in which carbon monoxide from carbon is the reducing agent. Carbon (coke or charcoal) is blended with zinc oxide and fed to a retort. The boiling point of pure zinc is low ( 900°C), so as the carbon is burned to form CO, the direct reduction of the zinc oxide by CO will result in the direct volatilization of the zinc. Cooling the vapor will condense the zinc, which can then be cast into ingots or alloyed with other metals. 

As we saw in Section 20.2, the reduction of iron oxides is accomplished by using carbon monoxide as a reducing agent. Starting with coke in a blast furnace, the following equilibrium plays a key role in the extraction of iron ... 

The reducticn of metal oxides is often accomplished using carbon monoxide as a reducing agent. Carbon (coke) and carbon dioxide are usually present, leading to the following reaction ... 

---