Visualising Co nanoparticle aggregation and encapsulation in Co/TiO2 catalysts and its mitigation through surfactant residues

DOI: 10.1016/j.jcat.2023.02.002

Authors: Chengwu Qiu (University College London; Research Complex at Harwell (RCaH)) , Yaroslav Odarchenko (University College London; Research Complex at Harwell (RCaH)) , Ines Lezcano-Gonzalez (University College London; Research Complex at Harwell (RCaH)) , Qingwei Meng (Guangdong University of Technology) , Tom Slater (Cardiff University) , Shaojun Xu (University College London; Research Complex at Harwell (RCaH)) , Andrew Beale (University College London; Research Complex at Harwell (RCaH))
Co-authored by industrial partner: No

Type: Journal Paper
Journal: Journal Of Catalysis , VOL 236

State: Published (Approved)
Published: February 2023
Diamond Proposal Number(s): 23984

Abstract: Due to the reducible nature of TiO2, the encapsulation of cobalt nanoparticles (CoNPs) by reduced TiO2-x is often reported to decrease their catalytic performance in reactions such as Fisher-Tropsch synthesis (FTS). Here, we show using HAADF-STEM imaging and electron energy loss spectroscopy (EELS) that a residual C12E4 surfactant used to prepare the CoNPs, remains on the surface of a TiO2 rutile support, preventing the formation of Ti3+/Ti2+ oxides and therefore TiO2-x migration. Furthermore, the presence of these surfactant residues prevents the coalescence and aggregation of CoNPs during catalyst preparation, maintaining the dispersion of CoNPs. As such, using C12E4 in the preparation of Co/TiO2 can be considered beneficial for producing a catalyst with a greater number of active Co species.

Subject Areas: Chemistry, Materials

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

Other Facilities: ISIS

Added On: 15/02/2023 08:41

Documents:
1-s2.0-S0021951723000453-main.pdf

Discipline Tags:

Physical Chemistry Catalysis Chemistry Materials Science Nanoscience/Nanotechnology

Technical Tags:

Microscopy Electron Microscopy (EM) Scanning Transmission Electron Microscopy (STEM)