Catalytic Synergy on PtNi Bimetal Catalysts Driven by Interfacial Intermediate Structures
Taek‐Seung Kim, Jeongjin Kim, Hee Chan Song, Daeho Kim, Beomgyun Jeong, Jouhahn Lee, Jae Won Shin, Ryong Ryoo, Jeong Young Park
Abstract
Platinum-based bimetallic catalysts exhibit surface atomic rearrangement in various adsorbate environments, which significantly impacts catalysis. A molecular-level understanding of intermediate structures created during catalysis is essential for developing high-performance bimetal catalysts. We show that intermediate Pt–NiO1–x interfacial structures drive the catalytic synergistic effect observed on Pt3Ni nanocrystals. Real-time microscopic observations at ambient pressure show the formation of oxygen-driven Ni oxide clusters on the surface and provide direct evidence of Pt–NiO1–x interfacial structure formation. Spectroscopic analysis, including ambient-pressure X-ray photoelectron spectroscopy and diffuse reflectance infrared Fourier-transform spectroscopy, and catalytic measurements elucidate the role of Pt–NiO1–x interfacial structures and the catalytic reaction mechanism in CO oxidation. Our results indicate that metal-oxide interfacial intermediate structures in bimetal catalysts relate to the catalytic enhancement of the strong metal–support interaction (SMSI) effect.