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Oxidative coupling reactions enable biomass-derived oxygenates to serve as sustainable platform molecules for a wide range of high-value chemicals. These catalytic reactions can be selectively triggered over alloys wherein a highly active dopant metal such as Pd is diluted into a sea of highly selective host metal atoms such as Au. Here, a range of supported Pd1Aux (x = 5–200) alloy nanoparticles were synthesized using a sequential reduction method with colloidal Au to achieve a high degree of compositional control and particle size uniformity. The promotional role of Pd was examined in the oxidation of ethanol to yield acetaldehyde and the coupling product ethyl acetate. Reactivity trends indicate that both the overall rate of ethanol oxidation and the selectivity toward coupling increase with Pd doping. Rate order and activation energy trends further suggest that the promotional role of Pd does not likely originate from simple O2 dissociation and spillover but rather from the stabilization of alkoxides at Pd-Au interfaces, disproportionately increasing coupling vs simple oxidation. Infrared spectroscopy and density functional theory calculations offer further insights into Pd microstructures in the presence of various key adsorbates, suggesting that Pd can lend this promotion in an isolated state. While this state is generally unstable in the surface due to preferences for segregation into the bulk, oxygen and pathway intermediates may aid in stabilizing surface structures. These findings lay groundwork to explain selectivity and activity control in a much wider range of oxidative functionalizations and to guide further catalyst development. 

Here, we show that C 4 –C 12 linear olefins, including linear alpha olefins, can be selectively produced from ethylene over a stable cobalt oxide on carbon catalyst. Both bulk and surface cobalt phases are CoO when the catalyst is stable, suggesting CoO is the stable cobalt phase for oligomerization. During the reaction, polyethylene forms in the catalyst pores which influences the product selectivity. The catalyst is more stable at higher temperatures (∼200 °C) likely due to reduction of Co 3 O 4 to CoO while rapid deactivation is observed at lower temperatures ( e.g. , 80–140 °C). The product selectivity can be fit to two different Schulz Flory distributions, one from C 4 to C 10 olefins and one above C 10 olefins, suggesting that transport restrictions influence product selectivity. At 48.3% conversion, product linearities up to C 12 olefins are above 90%, making it the most selective heterogeneous catalyst to linear olefins to date in the absence of activators and/or solvents.