Electronic parameters in cobalt-based perovskite-type oxides as descriptors for chemocatalytic reactions

Nature Communications, vol. 11, pp. 652

Abstract

Abstract Perovskite-type transition metal (TM) oxides are effective catalysts in oxidation and decomposition reactions. Yet, the effect of compositional variation on catalytic efficacy is not well understood. The present analysis of electronic characteristics of B-site substituted LaCoO3 derivatives via in situ X-ray absorption spectroscopy (XAS) establishes correlations of electronic parameters with reaction rates: TM t2g and eg orbital occupancy yield volcano-type or non-linear correlations with NO oxidation, CO oxidation and N2O decomposition rates. Covalent O 2p-TM 3d interaction, in ultra-high vacuum, is a linear descriptor for reaction rates in NO oxidation and CO oxidation, and for N2O decomposition rates in O2 presence. Covalency crucially determines the ability of the catalytically active sites to interact with surface species during the kinetically relevant step of the reaction. The nature of the kinetically relevant step and of surface species involved lead to the vast effect of XAS measurement conditions on the validity of correlations.

Authors 6

1. Johannes Simböck Aachen Center for Automotive Catalytic Systems Aachen Chair of Heterogeneous Catalysis and Chemical Technology

   RWTH Aachen University

   Affiliation as printed

   Center for Automotive Catalytic Systems Aachen, RWTH Aachen University, Aachen, 52074, Germany

   Chair of Heterogeneous Catalysis and Chemical Technology, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany

2. Mahnaz Ghiasi

   Utrecht University

   Affiliation as printed

   Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, Netherlands

3. Simon Schönebaum Aachen Center for Automotive Catalytic Systems Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Center for Automotive Catalytic Systems Aachen, RWTH Aachen University, Aachen, 52074, Germany

   Institute of Inorganic Chemistry, RWTH Aachen University, 52074, Aachen, Germany

4. Ulrich Simon Aachen Center for Automotive Catalytic Systems Aachen Institute of Inorganic Chemistry

   RWTH Aachen University

   Affiliation as printed

   Center for Automotive Catalytic Systems Aachen, RWTH Aachen University, Aachen, 52074, Germany

   Institute of Inorganic Chemistry, RWTH Aachen University, 52074, Aachen, Germany

5. Frank M. F. de Groot

   Utrecht University

   Affiliation as printed

   Inorganic Chemistry and Catalysis, Debye Institute for Nanomaterials Science, Utrecht University, Universiteitsweg 99, 3584 CG, Utrecht, Netherlands

6. Regina Palkovits corresponding Aachen Center for Automotive Catalytic Systems Aachen Chair of Heterogeneous Catalysis and Chemical Technology

   RWTH Aachen University

   Affiliation as printed

   Center for Automotive Catalytic Systems Aachen, RWTH Aachen University, Aachen, 52074, Germany. palkovits@itmc.rwth-aachen.de

   Chair of Heterogeneous Catalysis and Chemical Technology, RWTH Aachen University, Worringerweg 2, 52074, Aachen, Germany. palkovits@itmc.rwth-aachen.de

   Center for Automotive Catalytic Systems Aachen, RWTH Aachen University, Aachen, 52074, Germany