Palladium–Magnesium Oxide Nanocatalyst for Selective Hydrogenation: Enhancing Naphtha Stability and Biodiesel Performance

The hydrogenation of naphtha is critical to producing stable, clean gasoline, yet current catalysts often lack selectivity and stability.In this work, a novel palladium-magnesium oxide (Pd/MgO) nanocatalyst was developed to address these challenges.The catalyst was prepared by reduction of Na 2 PdCl 4 on MgO support using sodium borohydride, resulting in well-dispersed Pd nanoparticles with an average size of 1.7 nm and a Pd loading of 0.9 wt.% (nominally 1 wt.%).The size, composition, and dispersion of the nanoparticles were confirmed using transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, hydrogen pulse chemisorption, inductively coupled plasma atomic emission spectroscopy, and hydrogen temperature programmed reduction measurements.Catalytic tests showed great activity of quinoline hydrogenation at 150 C and 40 atm H, with a corrected turnover frequency (TOF corr ) of 6400 h, which was almost fourfold higher than Pd/SiO and Pd/AlO commercial catalysts (TOF corr = 1600-1800 h).Linear alkenes were hydrogenated with the catalyst at mild conditions (25 C and 10 atm H).Moreover, during biodiesel upgrading, the conversion of polyunsaturated fatty acid methyl esters to stable monounsaturated products was achieved at (100 C, 1 atm of H with >80 % conversion).Recyclability tests proved that the alkene hydrogenation activity was stable in three cycles, and only slight deactivation in quinoline hydrogenation occurred.This work shows that the Pd/MgO nanocatalysts are promising for enhancing the quality of gasoline, minimizing the formation of gums, and increasing the stability of biodiesel because of their nanoscale dispersion, high selectivity, and recyclability.