The “electric-dipole” effect of Pt–Ni for enhanced catalytic dehydrogenation of ammonia borane

Abstract

In this work, we prepared the PtNi alloy nanoparticles on Al2O3 (Al2O3–PtNi) via a simple wet-grinding method followed by a thermal reduction process. The as-prepared Al2O3–PtNi displayed a higher TOF of 426.84 molH2 (molPt·min)−1 toward the dehydrogenation of AB (ammonia borane) than Al2O3–Pt and Al2O3–Ni. Based on the theoretical calculations, an “electric-dipole” effect generated by the neighboring Pt–Ni atoms was found to facilitate the catalytic dehydrogenation process of ammonia borane (AB). The external electric field produced by the Pt–Ni dipole can elongate the B–H bond and increase the negative charges of H atoms on the BH3 group, which helps to activate the B–H bond in the AB molecule, and thus enhances the kinetic process of catalysis.