Mg-modified Al2O3 regulates the supported Pd with Pd0/Pd2+ ratio for 2-butyn-l-ol semi-hydrogenation performance

[Display omitted] •Mg-modified alumina-loaded Pd catalyst for selective hydrogenation of acetylenic alcohols using a support modification strategy.•Pd0.5/Mg1@γ-Al2O3 catalyst achieved 99 % conversion of 2-butyne-1-ol and 97 % selectivity of cis-2-buten-1-ol at 25 °C and 0.1 MPa.•The selectivity of the acetylenic alcohol semi-hydrogenation reaction was regulated by adjusting the ratio of Pd0/Pd2+.•The strategy of modulating the electronic structure of the active metal Pd by introducing metal modifications to the support can be extended to other alkyne semi-hydrogenation systems. Precise regulation of reaction selectivity at high conversions is the key to non-terminated alkyne semi-hydrogenation. Herein, a support modification strategy was employed to incorporate trace amounts of Mg elements into alumina support. The modified support loaded Pd catalyst optimized the activity and selectivity of the non-terminated alkyne semi-hydrogenation reaction. The TEM and XRD characterization of the catalysts demonstrated the entry of Mg elements into the Al2O3 lattice to achieve the modification of the support. For the 2-butyne-1-ol semi-hydrogenation reaction, the Pd0.5/Mg1@Al2O3 catalyst showed 99 % conversion and 97 % selectivity of the cis product at hydrogen pressure of 0.1 MPa and 25 °C. The introduced Mg element changed the electronic structure of Pd nanoparticles in the catalyst. The precise regulation of the 2-butyne-1-ol semi-hydrogenation reaction was achieved by adjusting the ratio of Pd0 to Pd2+ using the synergistic effect of Pd0 and Pd2+.