Operando HERFD-XAS of La(Mn,Ni)O3 in the CO oxidation: thin films and nanoparticles

Perovskite transition metal oxides (ABO3) are cost-efficient catalysts for CO oxidation reactions. Yet, the effect of thin films and nanoparticles variation on the catalytic mechanism is not understood well. We will investigate the differences between nanoparticles and thin films. In addition, we will study the B-site doping effect in LaMnxNi1-xO3. Using high-energy resolution fluorescence detection (HERFD), we will study HERFD-XAS of La(Mn,Ni)O3 thin films (thickness: 0.4-10 nm) and nanoparticles (size: 30-50 nm) under operando conditions. The HERFD-XAS pre-edges contain 1s3d quadrupole local and 1s4p pre-edge nonlocal transitions, in which the extracted information of spin state and covalency plays a vital role in describing the activity. Moreover, we will measure the 1s2p RIXS that probes the “L2,3 XAS-like” information. We will use DFT and charge transfer multiplet calculations[3-5] in order to simulate the HERFD-XAS and the 1s2p RIXS, respectively.