Phosphorus as a Promoter of a Nickel Catalyst to Obtain 1-phenylethanol from Chemoselective Hydrogenation of Acetophenone.

DOLLY C. COSTA; ANALÍA L. SOLDATI; JOSÉ F. BENGOA; SERGIO G. MARCHETTI; VIRGINIA VETERE

Heliyon

Elsevier

Lugar: Amsterdam; Año: 2019 vol. 5

2405-8440

Two catalysts are prepared using monodisperse pre-synthetized nanoparticles of metallic nickel and nickel phosphides with the same average diameter. Both nanoparticles species are deposited on the same support: mesoporous silicanano-spheres of MCM-41 (MSNS). This support is adequate to inhibit agglomeration and sintering processes during preparation steps. Therefore, two supported and activated catalysts with the same average nanoparticles diameter areobtained. They only differ in the nature of the active species: metallic nickel and nickel phosphides. The effect of the presence of a second element (phosphorus), more electronegative than nickel, on the activity and selectivity in the chemoselective hydrogenation of acetophenone is studied. The reaction conditions are: H2 pressure of 1 MPa, 80 ºC using n-heptane as solvent. With the aim to understand the catalytic results, nanoparticles, support and catalysts are carefully characterized by XRD, DLS, TEM, HRTEM, SAED, SEM, FT-IR, N2 adsorption a 77 K, atomic absorption, H2 and CO chemisorption and volumetric oxidation. Taking into account these results and geometric and electroniccharacteristics of the surface of both active species, a change in the intermediate adsorption state of acetophenone in phosphorus presence is proposed to explain the hydrogenation chemoselective capacity of the nickel phosphides.