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In this report, density functional theory (DFT) calculations of O and OH binding energies on triatomic surface ensembles of Pd x Ir (100−x) nanoalloys successfully predicted the overall trend in experimental oxygen reduction reaction (ORR) activity as a function of nanoparticle (NP) composition. Specifically, triatomic Pd 3 ensembles were found to possess optimal O and OH binding energies and were predicted to be highly active sites for the ORR, rivaling that of Pt(111). However, DFT calculations suggest that the O binding energy increases at active sites containing Ir, thereby decreasing ORR activity. Pd x Ir (100−x) nanoalloys were synthesized using a microwave-assisted method and their activity towards the ORR was tested using rotating disk voltammetry (RDV). As predicted, the bimetallic electrocatalysts exhibited worse catalytic activity than the Pd-only NPs. The strong qualitative correlation between the theoretical and experimental results demonstrates that the activity of individual active sites on the surface of NPs can serve as a proxy for overall activity. This is a particularly useful strategy for applying DFT calculations to electrocatalysts that are too large for true first-principle analysis. 

Controlled partial decomposition of 2-selenonicotinic acid in the presence of Co 2+ or Ni 2+ resulted in the in situ formation of an unusual MOF based on triselenane ligands (RSeSeSeR) coordinated to M 2+ centers as NSeN-pincers. Post-synthetic oxidation by treatment with aqueous H 2 O 2 facilitates its solid-state conversion into a RSeO 2 − molecular coordination complex, which was tracked via powder X-ray diffraction studies and by single-crystal structural resolution of the final product.