Micro Kinetic Modeling of Catalytic Reaction Sequence by Drawing Analogous Electrical Analogy
MICRO KINETIC MODELING OF CATALYTIC REACTION SEQUENCE BY DRAWING ANALOGOUS ELECTRICAL ANALOGYReduction of NO by CO[pic 1][pic 2]The catalytic reaction sequence for the reduction of NO by CO on Pt is as follows:s1 [pic 3]s2 [pic 4]s3 [pic 5]s4 [pic 6]s5 [pic 7]s6 [pic 8]s7 [pic 9]s8 [pic 10]Number of elementary steps : p = 8Number of intermediate species : q = 6Therefore, Number of independent pathways/routes = p-q = 2The above reaction is not exactly a mechanism involving parallel pathway and obviously does not involve series pathway. Hence, drawing an electrical amalogy for such a typical reaction is the major challenge.Electrical analogy for the above reaction sequence is as follows:[pic 11][pic 12][pic 13][pic 14][pic 15][pic 16][pic 17][pic 18][pic 19][pic 20][pic 21][pic 22][pic 23][pic 24]
Conversion of wye network to delta network:[pic 25]Here,Rj = (RARB+RBRC+RCRA)/RBRi = (RARB+RBRC+RCRA)/RCRk = (RARB+RBRC+RCRA)/RAWhere,RA = 2R1+R2+R4+R5+R8RB = R2+R3+R4+R5+R8RC = R6+R7Also,rOR1 = (1-zOR1)/RjrOR2 = (1-zOR2)/Riwhere,KOR1 = K12K2K4K5K6K7K8KOR2 = (K1K2K4K5K8)2K3zOR1 = (pN2pCO22)/( KOR1pNO2pCO2)zOR2 = (pN2OpCO2)/( KOR2 pNO2pCO)Given below are the rate equations for each reaction:r1 = w1fƟo – w1bƟNO.Sr2 = w2fƟoƟNO.S – w2bƟN.SƟO.Sr3 = w3fƟN.S2 – w3bƟo2r4 = w4fƟo – w4bƟCO.Sr5 = w5fƟCO.SƟO.S – w5bƟo2