Catalytic decomposition of nitrous oxide N 2O: a study for p-block-element lead in PbO—ZrO2/Al2O3 systems (original) (raw)

1996, Applied Catalysis B: Environmental

PbO-ZrO, catalysts have been prepared by sequential impregnation/calcination onto Al,O, support for high concentration N,O (27.97 mol%) decomposition. The p-block-element involved material system has been investigated with GC, BET, DTA, XRD and catalytic activity evaluation. It is found that with an atomic ratio Pb:Zr = I:6 the material system shows the best catalytic performance for the decomposition. The catalyst with this composition has a tetragonal phase of ZrO, over reaction temperatures. The catalytic activity observed can be attributed to the presence of Pb cations with mixed valence states in tetragonal ZrO, lattice. Doping gases such as H,O, CO,, and 0, are also mixed into the N,O and studied. It is found that N,O adsorption is rate-limiting step for the decomposition reaction. The reaction can be described as first order with respect to partial pressure of N,O, considering that decomposition product 0, exhibits no inhibition effect on the reaction in high conversion region.