skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys

Abstract

Alloying palladium (Pd) with other transition metals at the nanoscale has become an important pathway for preparation of low-cost, highly-active and stable catalysts. However the lack of understanding of how the alloying phase state, chemical composition and atomic-scale structure of the alloys at the nanoscale influence their catalytic activity impedes the rational design of Pd-nanoalloy catalysts. This work addresses this challenge by a novel approach to investigating the catalytic oxidation of carbon monoxide (CO) over palladium-nickel (PdNi) nanoalloys with well-defined bimetallic composition, which reveals a remarkable a maximal catalytic activity at Pd:Ni ratio of ~50:50. Key to understanding the structural-catalytic synergy is the use of high-energy synchrotron X-ray diffraction coupled to atomic pair distribution function (HE-XRD/PDF) analysis to probe the atomic structure of PdNi nanoalloys under controlled thermochemical treatments and CO reaction conditions. Three-dimensional (3D) models of the atomic structure of the nanoalloy particles were generated by reverse Monte Carlo simulations (RMC) guided by the experimental HE-XRD/PDF data. Structural details of the PdNi nanoalloys were extracted from the respective 3D models and compared with the measured catalytic properties. The comparison revealed a strong correlation between the phase state, chemical composition and atomic-scale structure of PdNi nanoalloys and their catalytic activitymore » for CO oxidation. This correlation is further substantiated by analyzing the first atomic neighbor distances and coordination numbers inside the nanoalloy particles and at their surfaces. These findings have provided new insights into the structural synergy of nanoalloy catalysts by controlling the phase state, composition and atomic structure, complementing findings of traditional density functional theory studies.« less

Authors:
; ; ; ; ; ; ; ; ;
Publication Date:
Research Org.:
Pacific Northwest National Laboratory (PNNL), Richland, WA (US), Environmental Molecular Sciences Laboratory (EMSL)
Sponsoring Org.:
USDOE
OSTI Identifier:
1132220
Report Number(s):
PNNL-SA-101786
48215; KP1704020
DOE Contract Number:  
AC05-76RL01830
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the American Chemical Society, 136(19):7140-7151
Country of Publication:
United States
Language:
English
Subject:
Palladium, nickel, nanoalloy, catalysts, CO oxidation, high-energy X-ray diffraction, pair distribution function, first atomic neighbor distances and coordination numbers; Environmental Molecular Sciences Laboratory

Citation Formats

Shan, Shiyao, Petkov, Valeri, Yang, Lefu, Luo, Jin, Joseph, Pharrah, Mayzel, Dina, Prasai, Binay, Wang, Lingyan, Engelhard, Mark H., and Zhong, Chuan-Jian. Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys. United States: N. p., 2014. Web. doi:10.1021/ja5026744.
Shan, Shiyao, Petkov, Valeri, Yang, Lefu, Luo, Jin, Joseph, Pharrah, Mayzel, Dina, Prasai, Binay, Wang, Lingyan, Engelhard, Mark H., & Zhong, Chuan-Jian. Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys. United States. doi:10.1021/ja5026744.
Shan, Shiyao, Petkov, Valeri, Yang, Lefu, Luo, Jin, Joseph, Pharrah, Mayzel, Dina, Prasai, Binay, Wang, Lingyan, Engelhard, Mark H., and Zhong, Chuan-Jian. Mon . "Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys". United States. doi:10.1021/ja5026744.
@article{osti_1132220,
title = {Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys},
author = {Shan, Shiyao and Petkov, Valeri and Yang, Lefu and Luo, Jin and Joseph, Pharrah and Mayzel, Dina and Prasai, Binay and Wang, Lingyan and Engelhard, Mark H. and Zhong, Chuan-Jian},
abstractNote = {Alloying palladium (Pd) with other transition metals at the nanoscale has become an important pathway for preparation of low-cost, highly-active and stable catalysts. However the lack of understanding of how the alloying phase state, chemical composition and atomic-scale structure of the alloys at the nanoscale influence their catalytic activity impedes the rational design of Pd-nanoalloy catalysts. This work addresses this challenge by a novel approach to investigating the catalytic oxidation of carbon monoxide (CO) over palladium-nickel (PdNi) nanoalloys with well-defined bimetallic composition, which reveals a remarkable a maximal catalytic activity at Pd:Ni ratio of ~50:50. Key to understanding the structural-catalytic synergy is the use of high-energy synchrotron X-ray diffraction coupled to atomic pair distribution function (HE-XRD/PDF) analysis to probe the atomic structure of PdNi nanoalloys under controlled thermochemical treatments and CO reaction conditions. Three-dimensional (3D) models of the atomic structure of the nanoalloy particles were generated by reverse Monte Carlo simulations (RMC) guided by the experimental HE-XRD/PDF data. Structural details of the PdNi nanoalloys were extracted from the respective 3D models and compared with the measured catalytic properties. The comparison revealed a strong correlation between the phase state, chemical composition and atomic-scale structure of PdNi nanoalloys and their catalytic activity for CO oxidation. This correlation is further substantiated by analyzing the first atomic neighbor distances and coordination numbers inside the nanoalloy particles and at their surfaces. These findings have provided new insights into the structural synergy of nanoalloy catalysts by controlling the phase state, composition and atomic structure, complementing findings of traditional density functional theory studies.},
doi = {10.1021/ja5026744},
journal = {Journal of the American Chemical Society, 136(19):7140-7151},
number = ,
volume = ,
place = {United States},
year = {Mon May 05 00:00:00 EDT 2014},
month = {Mon May 05 00:00:00 EDT 2014}
}