Single-atom metal catalysts offer a promising way to utilize precious noble metal elements more effectively, provided that they are catalytically active and sufficiently stable. Herein, we report a synthetic strategy for Pt single-atom catalysts with outstanding stability in several reactions under demanding conditions. The Pt atoms are firmly anchored in the internal surface of mesoporous Al2O3, likely stabilized by coordinatively unsaturated pentahedral Al3+ centres. The catalyst keeps its structural integrity and excellent performance for the selective hydrogenation of 1,3-butadiene after exposure to a reductive atmosphere at 200 °C for 24 h. Compared to commercial Pt nanoparticle catalyst on Al2O3 and control samples, this system exhibits significantly enhanced stability and performance for n-hexane hydro-reforming at 550 °C for 48 h, although agglomeration of Pt single-atoms into clusters is observed after reaction. In CO oxidation, the Pt single-atom identity was fully maintained after 60 cycles between 100 and 400 °C over a one-month period.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: We thank the National University of Singapore Young Investigator Award (WBS: R-279-000-464-133) for financial support. HAADF-STEM measurement at King Abdullah University of Science and Technology, Saudi Arabia; 27Al MAS NMR measurements were carried out at Dalian Institute of Chemical Physics, Chinese Academy of Sciences, China; the XAS measurements were performed at the BL5S2 at the Aichi Synchrotron Radiation Center under the approval of Aichi Science & Technology Foundation, Aichi, Japan (Proposal No. 201506061) and at the BL01B1 at the SPring-8 (Japan Synchrotron Radiation Research Institute, Hyogo, Japan) under the approval of JASRI (Proposal No. 2016A1025). The XAS measurement at the AichiSR was financially supported by the Nagoya University Synchrotron Radiation Research Center.