Reactions of Redox-Activated Complexes with Gaseous Substrates

6 Reactions of Redox-Activated Complexes with Gaseous Substrates 

The activation of gaseous molecules such as H2, N2, O2, CO, and CO2 is important both for environmental and economic reasons and the SEC study of catalysts for activation of these species is facilitated by cells capable of operation at elevated pressures. This feature may be incorporated into external reflection SEC designs and a schematic diagram of such a cell is shown in 

Time evolution of the concentration of 3S and products formed following reduction for ca. 6 s, at this time ( = 0 s) the potentiostat was switched to open circuit. The concentration change is obtained by multicomponent analysis of the dilferential absorption IR spectra. The values of the concentration change for 3S are olfset by 2.1 mM. The error bars are drawn at the 3 e.s.d. level. The mass balance corresponds to the sum of the concentration changes. The inset shows the change in concentration of 3S on a root timescale. Modified from ref. 19. 

An upper pressure limit for operation of the cell is set at 1 MPa, this is less than 10% of the calculated safe pressure. The change in concentration of gaseous substrates effected by a 1-MPa pressure is sufficient for satisfactory study of most systems. In addition to operation at elevated pressures the cell is very well suited to the study of highly air-sensitive compounds. 

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