Regioselective Generation of Single-Site Iridium Atoms and Their Evolution into Stabilized Subnanometric Iridium Clusters in MWW Zeolite
Preparation of supported metal catalysts with uniform particle size and coordination environment is a challenging and important topic in materials chemistry and catalysis. In this work, we report the regioselective generation of single-site Ir atoms and their evolution into stabilized subnanometric Ir clusters in MWW zeolite, which are located at the 10MR window connecting the two neighboring 12MR supercages. The size of the subnanometric Ir clusters can be controlled by the post-synthesis treatments and maintain below 1 nm even after being reduced at 650 °C, which cannot be readily achieved with samples prepared by conventional impregnation methods. The high structure sensitivity, size-dependence, of catalytic performance in the alkane hydrogenolysis reaction of Ir clusters in the subnanometric regime is evidenced. ; This work has been supported by the European Union through the European Research Council (grant ERC‐AdG‐2014‐671093, SynCatMatch) and the Spanish government through the "Severo Ochoa Program" (SEV‐2016‐0683). The authors also thank Microscopy Service of UPV for the TEM and STEM measurements. High‐resolution STEM measurements were performed at the DME‐UCA node of the ELECMI National Singular Infrastruture, in Cadiz University, with financial support from FEDER/MINECO (MAT2017‐87579‐R and MAT2016‐81118‐P). This research used resources of the Advanced Photon Source, an Office of Science User Facility operated for the U.S. Department of Energy (DOE) Office of Science by Argonne National Laboratory, and was supported by the U.S. DOE under Contract No. DE‐AC02‐06CH11357, and the Canadian Light Source and its funding partners. The financial support from ExxonMobil on this project is also greatly acknowledged.