Catalytic reduction of pyrolyzed biomass is required to remove oxygen and produce transportation fuels, but limited knowledge of how hydrodeoxygenation (HDO) catalysts work stymies the rational design of more efficient and stable catalysts, which in turn limits deployment of biofuels. This work reports results from a novel study utilizing both isotopically labeled phenol (which models the most recalcitrant components of biofuels) with D 2 O and DFT calculations to provide insight into the mechanism of the highly efficient HDO catalyst, Ru/TiO 2 . The data point to the importance of interface sites between Ru nanoparticles and the TiO 2 support and suggest that water acts as a cocatalyst favoring a direct deoxygenation pathway in which the phenolic OH is replaced directly with H to form benzene. Rather than its reducibility, we propose that the amphoteric nature of TiO 2 facilitates H 2 heterolysis to generate an active site water molecule that promotes the catalytic C−O bond scission of phenol. This work has clear implications for efforts to scale-up the hydrogen-efficient conversion of wood waste into transportation fuels and biochemicals.

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Desulfatibacillum alkenivorans AK-01 serves as a model organism for anaerobic alkane biodegradation because of its distinctive biochemistry and metabolic versatility. The D. alkenivorans genome provides a blueprint for understanding the genetic systems involved in alkane metabolism including substrate activation, CoA ligation, carbon-skeleton rearrangement and decarboxylation. Genomic analysis suggested a route to regenerate the fumarate needed for alkane activation via methylmalonyl-CoA and predicted the capability for syntrophic alkane metabolism, which was experimentally verified. Pathways involved in the oxidation of alkanes, alcohols, organic acids and n-saturated fatty acids coupled to sulfate reduction and the ability to grow chemolithoautotrophically were predicted. A complement of genes for motility and oxygen detoxification suggests that D. alkenivorans may be physiologically adapted to a wide range of environmental conditions. The D. alkenivorans genome serves as a platform for further study of anaerobic, hydrocarbon-oxidizing microorganisms and their roles in bioremediation, energy recovery and global carbon cycling.

Despite four additional electron‐withdrawing substituents, the octahalogenated porphyrins 2 are more easily oxidized than their tetra‐halogenated counterparts 1. This apparent paradox can be explained by the structures of the molecules: porphyrins 2 are almost planar, whereas in 1 steric interactions are minimized by a saddle conformation, which makes these porphyrins easier to oxidize.