Understanding the Strong Metal–Support Interaction (SMSI) Effect in CuxNi1–x/CeO2 (0 < x < 1) Nanoparticles for Enhanced Catalysis

The strong metal–support interaction (SMSI) effect plays a central role in catalysis by decreasing the catalytic activity or even improving it in some specific cases. In spite of the intense research, a detailed description of the SMSI effect in CeO2-based catalysts is still missing. In this work, CuxNi1–x/CeO2 (0 < x < 1) nanoparticles were exposed to a reduction treatment in a H2 atmosphere followed by an oxidation treatment in a CO2 atmosphere, both at 500 °C, and studied by using state-of-the-art techniques (in situ time-resolved X-ray absorption near edge structure (XANES) and near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS)). It was observed the migration of Cu (Ni) atoms toward the surface of Cu–Ni bimetallic nanoparticles during reduction (oxidation) treatments. The core–shell-like structure is dependent on the Cu/Ni ratio. It was observed the existence of a capping layer from the support (CeO2–x) surrounding the metallic nanoparticles after reduction treatment (characteristic of t...