Activating Pd nanoparticles via the Mott-Schottky effect in Ni doped CeO2 nanotubes for enhanced catalytic Suzuki reaction

Abstract

The eco-friendly and reusable heterogeneous Pd catalyst is an attractive alternative to the homogeneous Pd catalyst in the Suzuki reaction. However, the relatively low activity of heterogeneous Pd catalyst has become a major obstacle to its practical application. Herein, we construct the Mott-Schottky junctions at the interface between the CeO2 semiconductors and the supported Pd metals. Furthermore, the Ni dopants are introduced into the CeO2 lattices, thereby increasing the difference of Fermi level between CeO2 and Pd and further reducing the barrier of directional electron transfer from CeO2 to Pd. Meanwhile, the electronic structure of each element in the Pd/Ce1-xNixO2-δ is reconstructed by adjusting the Ni/Ce atomic ratio, so that the oxygen vacancy sites and the Ni sites act as electronic donors to induce the transfer of free electrons to the Pd. As a result, the electron-rich Pd/Ce0.9Ni0.1O2-δ catalysts exhibit high catalytic activity with a turnover frequency (TOF) value of 34,743 h−1 in Suzuki reactions.