TY - JOUR
T1 - Negative apparent kinetic order in steady-state kinetics of the water-gas shift reaction over a Pt-CeO2 catalyst
AU - Meunier, Frederic
AU - Yablonsky, G.
AU - Reid, D.
AU - Shekhtman, Sergiy
AU - Hardacre, Christopher
AU - Burch, Robbie
AU - Lazman, M.
PY - 2008/11
Y1 - 2008/11
N2 - The kinetics of the water-gas shift reaction Were Studied on a 0.2% Pt/CeO2 catalyst between 177 and 300 degrees C over a range of CO and steam pressures. A rate decrease with increasing partial pressure of CO was experimentally observed over this sample, confirming that a negative order in CO can occur under certain conditions at low temperatures. The apparent reaction order of CO measured at 197 degrees C was about -0.27. This value is significantly larger than that (i.e, -0.03) reported by Ribeiro and co-workers [A.A. Phatak, N. Koryabkina, S. Rai, J.L. Ratts, W. Ruettinger, R.J. Farrauto, G.E. Blau, W.N. Delgass, F.H. Ribeiro, Catal. Today 123 (2007) 224] at a similar temperature. A kinetic peculiarity was also evidenced, i.e. a maximum of the reaction rate as a function of the CO concentration or possibly a kinetic break, which is sometimes observed in the oxidation of simple molecules. These observations support the idea that competitive adsorption of CO and H2O play an essential role in the reaction mechanism. (C) 2008 Elsevier B.V. All rights reserved.
AB - The kinetics of the water-gas shift reaction Were Studied on a 0.2% Pt/CeO2 catalyst between 177 and 300 degrees C over a range of CO and steam pressures. A rate decrease with increasing partial pressure of CO was experimentally observed over this sample, confirming that a negative order in CO can occur under certain conditions at low temperatures. The apparent reaction order of CO measured at 197 degrees C was about -0.27. This value is significantly larger than that (i.e, -0.03) reported by Ribeiro and co-workers [A.A. Phatak, N. Koryabkina, S. Rai, J.L. Ratts, W. Ruettinger, R.J. Farrauto, G.E. Blau, W.N. Delgass, F.H. Ribeiro, Catal. Today 123 (2007) 224] at a similar temperature. A kinetic peculiarity was also evidenced, i.e. a maximum of the reaction rate as a function of the CO concentration or possibly a kinetic break, which is sometimes observed in the oxidation of simple molecules. These observations support the idea that competitive adsorption of CO and H2O play an essential role in the reaction mechanism. (C) 2008 Elsevier B.V. All rights reserved.
UR - http://www.scopus.com/inward/record.url?scp=53449100944&partnerID=8YFLogxK
U2 - 10.1016/j.cattod.2008.05.023
DO - 10.1016/j.cattod.2008.05.023
M3 - Article
SN - 0920-5861
VL - 138
SP - 216
EP - 221
JO - Catalysis Today
JF - Catalysis Today
IS - 3-4
ER -