Effect of dz2 orbital electron-distribution of La-based inorganic perovskites on surface kinetics of a model reaction

Abstract

Lanthanum-based perovskites, LaMO₃ (M = Co, Fe, Mn, Ni, Cr, Cu, Zn) were synthesized using sol–gel method and characterised using both physical and chemical techniques. Despite the prominence of inorganic perovskites in catalysis, catalyst-specific descriptors that enable design of reaction- or substrate-specific catalysts are not clearly defined. In this work, we put more emphasis on HOMO electron distributions in the degenerate e_g orbital of first row transition metals in the B-site of La-based inorganic perovskites. Herein, preliminary findings obtained using density functional theory calculations indicate that the oxidation of morin is dependent on the occupation of the d_z² orbital rather than the entire e_g orbital. Regions of low and high d_z² orbital occupation result in high catalytic activity compared to half-filled occupation. Furthermore, the LaCrO₃ perovskite with a lowest surface area, 2.7 m² g⁻¹ gave the highest activity, 7.16 × 10⁻² s⁻¹ suggesting that the surface area cannot be used as the sole descriptor for catalytic activity.