Increasing Pt selectivity to vinylaniline by alloying with Zn via reactive metal-support interaction
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 approximate to 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 mm 1) and 3-VA selectivity (S3-VA = 97% at X3-Ns approximate to 100%) in ethanol. The obtained activation energy (E-a = 40 kJ mol(-1)) is in agreement with the literature values for nitroarenes hydrogenation. The variation of H-2 partial pressure had no significant effect on the products distribution while increasing reaction rate in accordance to the first-order kinetics. (C) 2015 Elsevier B.V. All rights reserved.