Catalytic activity and thermal stability of arc plasma deposited Pt nano-particles on CeO₂-Al₂O₃

In this study, catalytic activity and thermal stability of the arc plasma deposited (APD) Pt nano-particles on Al₂O₃ and CeO₂-Al₂O₃ were compared with that of the conventionally prepared Pt/Al₂O₃. All the catalysts were characterized by BET-surface area, transmission electron microscopy, X-ray photoelectron spectroscopy, CO-pulse chemisorption, H₂-temperarture programmed reduction and X-ray absorption near edge spectroscopy. Through the quantum chemical calculations of different metal oxide support, CeO₂ was identified as a suitable anchoring material with high energy level between the Pt species (Pt⁰ and PtO_x) on ceria. Subsequently, the results of XPS and XANES revealed the presence of abundant Pt⁰ metal species in APD catalysts. The addition of ceria to Al₂O₃ support enhanced the dispersion of Pt nano-particles. The H₂-TPR of Pt/CeO₂-Al₂O₃ (APD) catalyst showed high-temperature reduction peaks corresponding to the interaction of Pt with ceria on alumina by Pt-O-Ce. Consequently, the Pt nano-particles deposited on CeO₂-Al₂O₃ by APD attained strong thermal resistance at high temperatures. In addition, superior catalytic activities for CO and C₃H₆ oxidation and NO_x reduction were obtained for the Pt/CeO₂. Al₂O₃ (APD) catalyst.