速報
触媒担体の格子酸素が関わるNO-CO反応の理論的解析
キーワード:
Three-way catalyst,
Mars-van Krevelen mechanism,
Lattice oxygen,
NO-CO reaction,
First-principle calculation
2019 年 18 巻 3 号 p. 139-141
詳細
2019 年 18 巻 3 号 p. 139-141
Three-way catalyst (TWC) purifies CO, hydrocarbons, and NOx contained in the exhaust gas of automobiles to CO2 and N2 by the redox reaction. Generally, active metals, i.e., Pt, Pd, and Rh, are supported on a metal oxide surface such as Al2O3. Among the metals, only Rh exhibits a catalytic activity for NOx reduction including N–O bond dissociation. Known as Mars-van Krevelen mechanism, reducible metal oxides such as CeO2 lead to CO oxidization by using lattice oxygen. A recent experimental study reported the catalytic activity of Pt and Pd for the NOx reduction with the help of the oxygen vacancy site of the metal oxide surface. The present study performs a systematic investigation of CO oxidation using the subsurface oxygen and NOx reduction with oxygen vacancy for various combinations of metals and metal oxides such as {Cu, Ru, Rh, Pd, Ir, Pt} and {CeO2, TiO2, ZrO2}.
