Consider the catalytic reaction as a function of the initial partial pressures 2A←→B+C The rate of disappearance of species A was obtained in a differential reactor and is shown below.

Three graphs compare the initial partial pressures of species A, B, and C, with the rate of disappearance of species A, denoted as negative r subscript A, 0. In graph A, P subscript A0 is compared with negative r subscript A, 0. A curve connecting 6 plots from the origin gradually increases and becomes flat at a point where the negative r subscript A, 0 is constant for increasing values of P subscript A0. The curve indicates P subscript C0 equals P subscript B0 equals 0. In graph B, P subscript B0 is compared with negative r subscript A, 0. In graph 4 plots connect horizontally where negative r subscript A, 0 is constant for increasing values of P subscript B0. The curve indicates P subscript A0 equals P subscript C0 equals 1 atmosphere. In graph C, P subscript C₀ is compared with negative r subscript A, 0, a curve connecting 6 plots from the negative r subscript A, 0 gradually decreases constantly for increasing values of P subscript C0. The curve indicates P subscript A₀ equals a atmosphere, and P subscript B0 equals 1 atmosphere.
a. What species are on the surface?
b. What does Figure B tell you about the reversibility and what’s adsorbed on the surface?
c. Derive the rate law and suggest a rate-liming step consistent with the above figures.
d. How would you plot your data to linearize the initial rate data in Figure A?
e. Assuming pure A is fed, and the adsorption constants for A and C are KA = 0.5 atm^–1 and KC = 0.25 atm^–1 respectively, at what conversion are the number of sites with A adsorbed on the surface and C adsorbed on the surface equal?

Transcribed Image Text:

-1A.0 Pco=PB0 = 0 PAD A -TA,0 PAO = Pco = 1 atm PBD B TAO PAO 1 atm PB0= 1 atm Pco C