Efficient Electronic State Regulation Engineering on Pd Single Atom by the Defect Engineering of the Bn Support for Acetylene Semi-Hydrogenation

Abstract

In this paper, BN, which is not commonly applied in acetylene hydrogenation, was used as the modifier to enhance the catalytic performance of Pd and it was directly used as the support. A catalyst model: Pd single atom anchoring on BN support was further established. This model excluded interference and had a single object, which facilitated the accurate investigation on the mechanism of the support's action on the metal. By using defect engineering to modulate the number of BN defects, the electronic state regulation engineering on the Pd atom was fulfilled. The experimental results of XRD, TEM, XPS, H2-TPR, and C2H2-TPD demonstrated that BN defects increased the electron density of Pd, thereby promoting ethylene desorption. Pd/BN achieved a 100% acetylene conversion and 93% ethylene selectivity, with good stability. Finally, through theoretical calculations, it clarified that the Pd atom coordinated with the N defect site of BN.

Keywords: BN, Pd catalyst, single atom catalyst, defect engineering, acetylene semi-hydrogenation