The activity of Pt-Re surfaces was studied for the water-gas shift (WGS) reaction in order to understand how Pt-Re interactions and cluster-support interactions influence activity. The results from these studies were also compared with previous reports of WGS activity on Pt-Re clusters grown on TiO. Platinum on Re surfaces were prepared by annealing Re films on Pt(111) to form Pt-Re surface alloys, depositing Pt on Re/Pt(111), and depositing Pt on Re clusters supported on highly oriented pyrolytic graphite (HOPG) surfaces. In all cases, the turnover frequency (TOF) for the WGS reaction was higher for Pt with subsurface Re compared to pure Pt. Furthermore, the TOF for 2 ML Pt/TiO clusters was greater than that of Pt(111) and 2 ML Pt/HOPG clusters, indicating that the TiO support enhances activity for the WGS reaction on Pt. For Pt/TiO clusters, a plot of the fraction of perimeter/surface sites as a function of Pt coverage closely follows TOF vs Pt coverage, strongly suggesting that activity occurs at the Pt-TiO interface. Notably, the fraction of undercoordinated sites as a function of Pt coverage does not follow the same behavior as the TOFs.
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http://dx.doi.org/10.1063/1.5128735 | DOI Listing |
Chemistry
December 2024
Beijing Key Laboratory of Ionic Liquids Clean Process, CAS Key Laboratory of Green Process and Engineering, State Key Laboratory of Mesoscience and Engineering, Institute of Process Engineering, Innovation Academy for Green Manufacture, Chinese Academy of Sciences, Beijing, 100190, China.
The alloying of platinum (Pt) with rare earth (RE) metals has emerged as a highly promising strategy for enhancing both the activity and stability of catalysts. Consequently, the development of methods for the controlled synthesis of Pt-RE alloys has received growing attention. This review comprehensively explores diverse synthesis methodologies for Pt-RE alloys, including physical metallurgy method, chemical reduction method, electrodeposition method, and dealloying method.
View Article and Find Full Text PDFACS Appl Mater Interfaces
April 2024
State Key Laboratory of Chem/Bio-Sensing and Chemometrics, Provincial Hunan Key Laboratory for Graphene Materials and Devices, College of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, China.
PtRu alloys have been recognized as the state-of-the-art catalysts for the methanol oxidation reaction (MOR) in direct methanol fuel cells (DMFCs). However, their applications in DMFCs are still less efficient in terms of both catalytic activity and durability. Rare earth (RE) metals have been recognized as attractive elements to tune the catalytic activity, while it is still a world-class challenge to synthesize well-dispersed Pt-RE alloys.
View Article and Find Full Text PDFRSC Adv
March 2024
Department of Chemistry, Presidency College (Autonomous) Chennai 600 005 India
Herein, we report, for the first-time, mesoporous carbon-supported binary and ternary catalysts with different atomic ratios of Pt/MC (100), Pt-Sn/MC (50 : 50), Pt-Re/MC (50 : 50), Pt-Sn-Re/MC (80 : 10 : 10) and Pt-Sn-Re/MC (80 : 115 : 05) prepared using a co-impregnation reduction method as anode components for membraneless ethanol fuel cells (MLEFLs). Mechanistic and structural insights into binary Pt-Sn/MC, Pt-Re/MC and ternary Pt-Sn-Re/MC catalysts were obtained using scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction (XRD) and energy-dispersive X-ray spectroscopy (EDX) methods. In particular, chemical characterization cyclic voltammetry, CO stripping voltammetry and chronoamperometry indicated that Pt-Sn-Re/MC (80 : 15 : 05) had better dynamics toward ethanol oxidation than Pt-Sn-Re/MC (80 : 10 : 10), Pt-Sn/MC (50 : 50) and Pt-Re/MC (50 : 50) catalysts.
View Article and Find Full Text PDFSmall
October 2023
School of Mechanical and Power Engineering, East China University of Science and Technology, Shanghai, 200237, P. R. China.
Platinum-rare earth metal (Pt-RE) nanoalloys are regarded as a potential high performance oxygen reduction reaction (ORR) catalyst. However, wet chemical synthesis of the nanoalloys is a crucial challenge because of the extremely high oxygen affinity of RE elements and the significantly different standard reduction potentials between Pt and RE. Here, this paper presents a molten-salt electrochemical synthetic strategy for the compositional-controlled preparation of platinum-neodymium (Pt-Nd) nanoalloy catalysts.
View Article and Find Full Text PDFInorg Chem
August 2022
Institute of Materials for Energy and Environment, School of Materials Science and Engineering, Qingdao University, Qingdao 266071, China.
To tune the activity of Pt alloy electrocatalysts and reduce the Pt loading, researchers have intensively studied alloys of Pt with late transition metals. However, Pt alloy formation with rare-earth (RE) elements through the traditional chemical route is still a challenge due to the vastly different standard reduction potentials. Here, we report a universal chemical method to prepare a series of Pt/RE (RE = La, Ce, Pr, Nd, Eu, Gd, Tb, Dy, Lu) nanoalloys with tunable compositions and ultrasmall particle sizes (sub-2 nm).
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