Tungsten- and molybdenum carbide catalysts of large particle size improve activity, stability and selectivity of the catalyst in (hydro)deoxygenation reactions.

Nearly monodispersed Au(38)(SC(12)H(25))(24) clusters (1.7 ± 0.2 nm) were synthesized using a modified Brust process while utilizing a "thiol etching" approach for the ligand exchange. HRTEM, MALDI, FTIR, and XAS analysis confirmed the formation of the 38-atom clusters in solution. This solution was used to impregnate a microporous TiO(2) support to give 0.7% Au(38)/TiO(2) catalyst. Subsequent drying in air and treatment with H(2)/He at 400 °C removed most of the sulfur ligands, and also increased the Au cluster size to 3.9 ± 0.96 nm. XPS and EXAFS analysis of this supported catalyst showed trace levels of residual sulfides, apparently located at the Au-TiO(2) interface. CO oxidation tests on these supported clusters show an activation energy and range of TOFs comparable to those reported by others. These results suggest that supported Au clusters of controllable size can be prepared with this thiol-ligated solution-based method, providing a new approach to the synthesis of these catalysts.

On the tip of the tung(sten): The title catalysts selectively perform deoxygenation of vegetable‐oil‐based feeds by either decarboxylation/decarbonylation or hydrodeoxygenation (HDO) pathways, depending on the dominant tungsten phase (WO3 and W2C). The process upgrades vegetable‐oil‐based feeds, under a hydrogen atmosphere, to high‐value olefinic products, thus providing a significant advantage over other types of deoxygenation catalysts.

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