Increasing Pt selectivity to vinylaniline by alloying with Zn via reactive metal–support interaction

• Pt/Zn intermetallic nanoparticles formed via metal (Pt)–support (ZnO) interactions.
• Pt–Zn alloy formation confirmed by XRD and XPS analyses.
• 97% yield to 3-vinylaniline achieved in hydrogenation of 3-nitrostyrene.
• Pt/ZnO allowed the highest 3-vinylaniline yield as compared to benchmark catalysts.

The promoting effect of Zn on Pt-based catalyst was studied for the liquid-phase hydrogenation of 3-nitrostyrene (3-NS). The monodispersed Pt nanoparticles (ca. 2.3 nm) supported on ZnO catalyzed the target 3-vinylaniline (3-VA) formation (S3-VA = 97% at X3-NS ≈ 100%). Such catalytic performance was attributed to the intermetallic Pt/Zn active phase formed via reactive metal (Pt)–support (ZnO) interaction during reductive calcinations. The reference catalysts (Pt/Al2O3, Pt/C, Pt/MgO and Pt/TiO2) have not provided such high selectivity under the same reaction conditions. The solvent effect was studied showing the highest activity (TOF = 64 min−1) and 3-VA selectivity (S3-VA = 97% at X3-NS ≈ 100%) in ethanol. The obtained activation energy (Ea = 40 kJ mol−1) is in agreement with the literature values for nitroarenes hydrogenation. The variation of H2 partial pressure had no significant effect on the products distribution while increasing reaction rate in accordance to the first-order kinetics.

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