The Oxidation of Carbon Monoxide by Solid Silver Permanganate Reagents: Vi. Reaction Kinetics and Adsorption of Water Vapor

Abstract

The temperature dependence of the rate constant, k, in the heterogeneous oxidation of carbon monoxide 011 the surface of silver permanganate -zinc oxide, indicates that in the temperature range of about 11" to 40°C., the process is subject to diffusion or transport control and the experime~ltal activation energy is 1.4 to 1.9 kcal. per mole. I n the range of 11" to -3OC. the rate of the surface chenlical reaction decreases with a corresponding increase in activation cnergy to 15 kcal. in this transition stage. At lower tenlperatures the system is subject to chemical control and E riscs to about 27 kcal.Four adsorption isotherms for water vapor 011 this reagent have been obtained in the range of -10" t o 20aC. The isotherms are signloid and illdicative of Type I1 adsorption.The mechanism of this heterogeneous reaction is discussed on the basis of several possibilities for providing oxygen ions in the electron-ion exchange step of the over-all reaction.

Solid-Phase Quasi-Intramolecular Redox Reaction of [Ag(NH3)2]MnO4: An Easy Way to Prepare Pure AgMnO2

“…The reaction of elementary silver or Ag 2 O with MnO, Mn 3 O 4 , and Mn 2 O 3 in the presence of oxygen yielded various silver manganese oxides with the {Ag x MnO 2 } n general formula like AgMnO 2 ( x = 1; n = 1), {Ag 2 MnO 2 } ( x = 2; n = 1), or Hollandite-type Ag 1.8 Mn 8 O 16 ( x = 0.225; n = 8). − Decomposition or reduction of AgMnO 4 (1:1 Ag/Mn stoichiometry) with H 2 , H 2 O 2 , CO, or metallic silver resulted in mixed oxides with the {AgMnO x } ( x = 2–3) composition. The composition of compound 1 and AgMnO 4 (Ag:Mn = 1:1) predetermined the stoichiometry of the single-phase decomposition product.…”

“…The endothermic NO formation resulted in a decrease of the overall positive energy balance. 43 or metallic silver 44 resulted in mixed oxides with the {AgMnO x } (x = 2−3) composition. The composition of compound 1 and AgMnO 4 (Ag:Mn = 1:1) predetermined the stoichiometry of the singlephase decomposition product.…”

Air Pollution

“…This gas has been determined in urban air by infrared spectroscopy (370). The oxidation of carbon monoxide by solid silver permanganate has been studied by Katz and his group (151,220,221).…”