Metal–Metal Oxide Catalytic Interface Formation and Structural Evolution: A Discovery of Strong Metal–Support Bonding, Ordered Intermetallics, and Single Atoms
Zihao Yan, Bingqing Yao, Connor Hall, Qiang Gao, Wenjie Zang, Hua Zhou, Qian He, Huiyuan Zhu
Abstract
In-depth investigation of metal–metal oxide interactions and their corresponding evolution is of paramount importance to heterogeneous catalysis as it allows the understanding and maneuvering of the structure of catalytic motifs. Herein, using a series of core/shell metal/iron oxide (M/FeOx, M = Pd, Pt, Au) nanoparticles and through a combination of in situ and ex situ electron and X-ray investigations, we revealed anomalous and dissimilar M–FeOx interactions among different systems under reducing conditions. Pd interacts strongly with FeOx after high-temperature reductive treatment, featured by the formation of Pd single atoms in the FeOx matrix and increased Pd–Fe bonding, while Pt transforms into ordered PtFe intermetallics and Pt single atoms immediately upon the coating of FeOx. In contrast, Au does not manifest strong bonding with FeOx. As a proof of concept of tailoring metal–metal oxide interactions for catalysis, optimized Pd/FeOx demonstrates 100% conversion and 86.5% selectivity at 60 °C for acetylene semihydrogenation.