Dataset for "Well-defined Cu pre-catalysts indicate design rules for reactivity in nitrate electroreduction"

We exploit well-defined Cu and Cu oxide nanocrystals (NCs) as pre-catalysts to elucidate these correlations. We find that size, shape and oxide content of the Cu pre-catalysts all play a role in driving the structural evolution and, thus, the catalytic behaviour during NO3RR. In particular, a higher oxide content, an optimized {111}/{100} facet ratio and the spatial proximity of these facets forming grain boundaries within the active catalysts emerge as the key factors to enhance NH3 selectivity. Among the studied Cu pre-catalysts, 10 nm Cu spheres integrate these key features achieving competitive NH3 production rate compared to the state of the art. This work links pre- and in situ formed catalyst features to catalytic performance, offering insights into the morphological dynamics of Cu catalysts under NO3RR conditions.