Publication

Article Metrics

Citations


Online attention

PtNi bimetallic structure supported on UiO-67 metal-organic framework (MOF) during CO oxidation

DOI: 10.1016/j.jcat.2020.09.013 DOI Help

Authors: Reza Vakili (The University of Manchester; University of Bath) , Thomas J. A. Slater (Diamond Light Source) , Christopher Hardacre (The University of Manchester) , Alex S. Walton (The University of Manchester) , Xiaolei Fan (The University of Manchester)
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Catalysis

State: Published (Approved)
Published: September 2020
Diamond Proposal Number(s): 23221

Open Access Open Access

Abstract: Supported bimetallic nanoparticles (BNPs) are promising catalysts, but study on their compositional and structural changes under reaction conditions remains a challenge. In this work, the structure of PtNi BNPs supported on UiO-67 metal-organic framework (MOF) catalyst (i.e., PtNi@UiO-67) was investigated by in situ by near ambient pressure X-ray photoelectron spectroscopy (NAP-XPS). The results showed differences in the reduction behaviour of Ni species in PtNi BNPs and monometallic Ni supported on UiO-67 catalysts (i.e., PtNi@UiO-67 and Ni@UiO-67), suggesting charge transfer between metallic Pt and Ni oxides in PtNi@UiO-67. Under CO oxidation conditions, Ni oxides segregated to the outer surface of the BNPs forming a thin layer of NiOx on top of the metallic Pt (i.e., a NiOx-on-Pt structure). This resulted in a core-shell structure which was confirmed by high-resolution scanning transmission electron microscopy (HR-STEM). Accordingly, the layer of NiOx on PtNi BNPs, which is stabilised by charge transfer from metallic Pt, was proposed as the possible active phase for CO oxidation, being responsible for the enhanced catalytic activity observed in the bimetallic PtNi@UiO-67 catalyst.

Journal Keywords: Bimetallic nanoparticle catalysts (BNPs); metal-organic frameworks (MOFs); CO oxidation; near-ambient pressure X-ray photoelectron spectroscopy (NAP-XPS); high-resolution scanning transmission electron microscopy (HRS-TEM)

Subject Areas: Chemistry, Materials

Diamond Offline Facilities: Electron Physical Sciences Imaging Centre (ePSIC)
Instruments: E01-JEM ARM 200CF

Added On: 30/09/2020 11:53

Documents:
1-s2.0-S002195172030381X-main.pdf

Discipline Tags:

Catalysis Physical Chemistry Materials Science Metallurgy Metal-Organic Frameworks Nanoscience/Nanotechnology Chemistry Organometallic Chemistry

Technical Tags:

Microscopy Electron Microscopy (EM) Transmission Electron Microscopy (TEM)