Structured Perovskite-Based Catalysts and Their Application as Three-Way Catalytic Converters—A Review

Abstract

Automotive Three-Way Catalysts (TWC) were introduced more than 40 years ago. Despite that, the development of a sustainable TWC still remains a critical research topic owing to the increasingly stringent emission regulations together with the price and scarcity of precious metals. Among other material classes, perovskite-type oxides are known to be valuable alternatives to conventionally used TWC compositions and have demonstrated to be suitable for a wide range of automotive applications, ranging from TWC to Diesel Oxidation Catalysts (DOC), from NO x Storage Reduction catalysts (NSR) to soot combustion catalysts. The interest in these catalysts has been revitalized in the past ten years by the introduction of the concept of catalyst regenerability of perovskite-based TWC, which is in principle well applicable to other catalytic processes as well, and by the possibility to reduce the amounts of critical elements, such as precious metals without seriously lowering the catalytic performance. The aim of this review is to show that perovskite-type oxides have the potential to fulfil the requirements (high activity, stability, and possibility to be included into structured catalysts) for implementation in TWC.

Catalytic Oxidation of Carbon Monoxide on Pd-Containing LaMnO3 Perovskites

“…According to the literature on the subject, the incorporation of Pd into the structure of the LaBO 3 perovskite depends on both the kind of cation in position B of the perovskite to which Pd is introduced [10,11,16,21] and the perovskite preparation method used [11]. The amount of the noble metal (Pd, Pt, Rh) which can form a solid solution with a perovskite-type oxide is different for each noble metal-perovskite combination [16] [18].…”

“…Such substitution changes the properties of the perovskite by inducing structural and electronic defects, which contribute to the perovskite's non-stoichiometry and thus considerably improve its catalytic activity [2,4]. The catalytic properties of the perovskite can be improved by partial substitution of the metal in position A or B with cations of noble metals: silver [3,5], platinum [6,7] or palladium [8][9][10][11][12][13][14][15][16][17][18][19][20][21]. [8][9][10].…”

“…The introduction of a noble metal into a perovskite prevents the sintering of the latter and a reduction in its mass as a result of volatilization at a high temperature in oxidizing conditions [16].…”

Structure, Ferromagnetic, Dielectric and Electronic Features of the $$\hbox {LaBiFe}_{2}\hbox {O}_{6}$$ LaBiFe 2 O 6 Material

“…The development of new perovskite-like materials has led to a frantic search of useful physical properties in the industry of solar cells [1], catalytic sensors [2] and spintronics [3], among others. In particular, the ferromagnetic perovskites, whose hysteresis curves show low coercivity and high saturation magnetization, are particularly examined because its potential prospects of applications in devices to store information on magnetic media, such as the well-known magnetic random access memories [4].…”

Perovskite Catalysts—A Special Issue on Versatile Oxide Catalysts

“…The review, contributed by Keav et al [4], scrutinizes perovskites as three-way catalysts. Catalyst design by B-site element selection, noble metal incorporation, catalyst preparation and implementation of perovskites in three-way catalytic (TWC) convertors are particularly emphasized.…”