Probing the local environment in potassium salts and potassium-promoted catalysts by potassium valence-to-core X-ray emission spectroscopy

we perform a systematic calibration study on a series of potassium salts in order to establish the information content of Kβ and VtC XES. The sensitivity of the K VtC XES to ligand identity and potassium-ligand distance is established. Our experimental results are correlated to density functional theory (DFT) calculations in order to more quantitatively assess the spectral changes. The potential of K VtC XES for future studies in chemical catalysis is highlighted through application of this method to a potassium-promoted iron ammonia synthesis catalyst.