Nickel molybdenum carbides: Synthesis, characterization, and catalytic activity in hydrodeoxygenation of anisole and ethyl caprate

- Ni-Mo alloy favors decarboxylation pathway of ethyl caprate conversion.
- The hydrodeoxygenation of ethyl caprate is preferred on Ni-Mo-C sites.
- β-Mo2C is responsible for hydrogenation reaction of ethyl caprate.
- Ni sites present in Ni-Mo alloy favor the hydrodeoxygenation of anisole.
- β-Mo2C leads to the formation of a high content of benzene.

Mo- and Ni-containing carbide catalysts were prepared by a Pechini-based method using citric acid as a complexing agent. All the catalysts were characterized by temperature-programmed reduction, X-ray diffraction (XRD), X-ray photoelectron spectroscopy, and N2 and CO sorption. The XRD experiments showed that the bimetallic systems contain phases: β-Mo2C and Mo3Ni2C and an alloy NixMo1−x with a high nickel content. The catalysts were tested in the hydrogenation of ethyl caprate and anisole. For the process with ethyl caprate, it was shown that the catalytic activity rises with an increase of the carbide phase content in the bimetallic catalysts. Further addition of nickel increases the amount of the Ni-Mo alloy, which leads to a drop in the catalytic activity and to an increase in the contribution of the decarboxylation pathway. The study of the carbide catalysts in anisole hydrogenation showed that a rise in the Ni/Mo ratio leads to an increase in activity.

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