X-ray absorption spectroscopy investigation of platinum–gadolinium thin films with different stoichiometry for the oxygen reduction reaction

Alloys of platinum and lanthanides present a remarkable activity for the oxygen reduction reaction—both in the form of extended surfaces and nanoparticulate catalysts. Co-sputter-deposited thin film catalysts based on platinum and gadolinium show great oxygen reduction activity improvement over pure Pt. The sputter-deposition technique represents a viable and versatile approach for investigating model catalyst systems with different compositions. In this work, co-sputtered Pt5 Gd and Pt7.5 Gd thin films were investigated using X-ray absorption spectroscopy as well as standardized electrochemical techniques. These investigations revealed the importance of forming alloys with specific stoichiometry, supporting the need of forming compressively strained Pt overlayers in order to achieve optimum catalytic performances.