From Structure to Selectivity: Operando Co K-edge XAS of Co/TiO₂ to determine the effect of water and Pt/Re promoters in Fischer-Tropsch for

We propose an operando XAS study to elucidate the deactivation mechanism of cobalt catalysts during the production of Sustainable Aviation Fuels (SAF) from CO/H2 mixture gases, and to determine how Pt and Re promoters influence this deactivation. To address this, we will employ XANES/EXAFS under realistic reaction conditions (20 bar, water-rich CO/H2 mixtures) to track oxidation state, coordination, bond lengths, and disorder in real time. This approach will enable quantification of the effects of Pt and Re on cobalt reducibility, dispersion, and structural stability, information that is inaccessible through XPS and XRD due to catalysts nature and harsh reaction conditions. By correlating XAS with catalytic activity and selectivity, as well as existing MES results, we aim to establish structure-performance relationships and derive design rules for cobalt catalysts prone to deactivation, advancing the developing of efficient SAF production technologies.