Tandem Base-Metal Oxide Catalyst for Automotive Three-way Reaction: MnFe2O4 for Preferential Oxidation of Hydrocarbon

• Published in: Catalysis Surveys from Asia Vol. 27; no. 1; pp. 48 - 55
• Main Authors: Maruichi, Keisuke, Sakai, Ryosuke, Ueda, Kakuya, Oda, Akira, Satsuma, Atsushi
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.03.2023; Springer Nature B.V
• Subjects: Bond energy; Catalysis; Catalysts; Cerium oxides; Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Copper; Electronegativity; Industrial Chemistry/Chemical Engineering; Manganese; Metal oxides; Original Article; Oxidation; Physical Chemistry; Platinum metals; Tandem configuration; PGM-free TWC; Propene-Preferential Oxidation; Ferrite-based metal oxides
• ISSN: 1571-1013; 1571-1013; 1574-9266
• DOI: 10.1007/s10563-022-09373-9

A combination of two base-metal oxides in tandem configuration can realize three-way reaction without platinum group metals. For this purpose, catalysts for hydrocarbon preferential oxidation (HC-PROX) and for NO reduction by CO are required. For the design of HC-PROX catalysts, competitive oxidation of propene and CO on spinel-type MFe 2 O 4 (M = Co, Cu, Mg, Mn, Ni, Zn) was investigated. MnFe 2 O 4 preferentially oxidized propene in the co-presence of CO showing the best propene oxidation activity. Among the series of MFe 2 O 4 , the activity controlling factor was correlated to the M-O bond energy of the second metal oxides, and the preference for HC oxidation was dependent on the electronegativity of the second ion. A tandem catalyst using MnFe 2 O 4 for HC-PROX and CuCo 2 O 4 for NO-CO reaction showed TWC activity comparable to a Rh/CeO 2 .