Research paperSemihydrogenation of 2-methyl-3-butyn-2-ol on Pd-Zn nanoalloys: Effect of composition and heterogenization

- Pd-Zn nanoparticles with various Pd/Zn molar ratios were prepared by chemical reduction method.
- Nanocrystalline Pd-Zn/TiO2 catalysts were synthesized by template sol-gel method.
- The relationship between nanoparticle composition and catalytic properties are established.
- 96.9% 2-methyl-3-buten-2 ol selectivity at 99% 2-methyl-3-butyn-2 ol conversion can be achieved over PdZn/TiO2 coating.

Influence of composition and heterogenization to titania matrix of Pd-Zn nanoparticles has been studied in selective hydrogenation of the triple bond of 2-methyl-3-butyn-2-ol (MBY). Pd-Zn bimetallic nanoparticles with the various molar ratios Pd/Zn have been obtained by chemical reduction method. Composition- controlled sol-gel technique was employed to synthesize Pd-Zn/TiO2 catalysts. The structure properties of the bimetallic catalysts were characterized by inductively coupled plasma atomic emission spectroscopy (ICP-AES), high-resolution transmission electron microscopy (HRTEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Computer modeling for XRD patterns was first used to identify the composition of Pd-Zn alloy and to determine the particle size. For the colloidal and embedded nanoparticles dependences of physicochemical and catalytic properties on composition are different being determined respectively by geometric and electronic effects. The addition of zinc with Pd/Zn ratio of 1 increased selectivity to alkene at 99% conversion from 92.9% for the Pd catalyst to 96.9% for bimetallic catalysts, which is mainly caused by alloy formation.

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