Defect and disorder modeling on tailored rare-earth oxides nanocatalysts

The understanding and control of oxygen vacancy dynamics in oxide catalysts for hydrocarbon oxidation reactions are critical for catalyst optimization. We propose to perform neutron total scattering experiments on mixed rare-earth oxide nanocatalysts used in methane conversion reactions. By varying the composition of a ternary fluorite-based oxide, local ordering of oxygen vacancies can be controlled to fine-tune vacancy dynamics, thereby maximizing the selectivity of methane conversion to C2 products. We aim to model the structural disorder and quantify both the amount and long-range distribution of oxygen defects. Through pair distribution function analysis, we will investigate the local atomic ordering to determine whether the symmetry corresponds to fluorite, pyrochlore, or a coexistence of both in a biphasic system, while also assessing the presence of defect clusters or other configurations. Data analysis will be based on reverse Monte Carlo methods, offering insights that link structural disorder to catalytic efficiency.