ERA

Download the full-sized PDF of Investigation of Highly Effective and Stable Electrocatalysts for Electrochemical CO2 Reduction at Room and Elevated TemperaturesDownload the full-sized PDF

Analytics

Share

Permanent link (DOI): https://doi.org/10.7939/R3ZK56126

Download

Export to: EndNote  |  Zotero  |  Mendeley

Communities

This file is in the following communities:

Graduate Studies and Research, Faculty of

Collections

This file is in the following collections:

Theses and Dissertations

Investigation of Highly Effective and Stable Electrocatalysts for Electrochemical CO2 Reduction at Room and Elevated Temperatures Open Access

Descriptions

Other title
Subject/Keyword
electrocatalysis
perovskite
electrocatalyst
CO2 reduction
Type of item
Thesis
Degree grantor
University of Alberta
Author or creator
Liu,Subiao
Supervisor and department
Luo, Jing-Li (Department of Chemica and Materials Engineering)
Examining committee member and department
Liu, Qingxia (Department of Chemica and Materials Engineering)
Shao, Zongping (Nanjing Tech University, China Joint appointed Curtin University, Australia)
Chung, Hyun-Joong (Department of Chemica and Materials Engineering)
Thundat, Thomas (Department of Chemica and Materials Engineering)
Department
Department of Chemical and Materials Engineering
Specialization
Chemical Engineering
Date accepted
2017-06-30T15:16:37Z
Graduation date
2017-11:Fall 2017
Degree
Doctor of Philosophy
Degree level
Doctoral
Abstract
To effectively reduce and utilize atmospheric CO2, electrochemically converting it to CO on an efficient and stable electrocatalyst at room and elevated temperatures has attracted extensive interests. However, present electrocatalysts usually suffer from sluggish kinetics, high overpotential, low selectivity and energy efficiency. Therefore, it is highly desirable to search for novel catalysts that can efficiently facilitate the CO2RR at room and elevated temperatures. I demonstrated a predominant shape-dependent electrocatalytic reduction of CO2 to CO on triangular silver nanoplates (Tri-Ag-NPs) in 0.1 M KHCO3 at room temperature. Compared with similarly sized Ag nanoparticles and bulk Ag, Tri-Ag-NPs exhibited an enhanced current density and significantly improved Faradaic efficiency and energy efficiency with a considerable durability. To further study the effects of electrocatalyst structure and employed solvent, I successfully prepared Ag2S nanowires (NWs) using a facile one-step method and utilized it as an electrocatalyst for CO2RR. Ag2S NWs in ionic liquid (IL) possess a partial current density of 12.37 mA cm-2, about 14 and 17.5-fold higher than those of Ag2S NWs in KHCO3 and bulk Ag. Moreover, it shows significantly higher selectivity with a value of 92.0% at η of -0.754 V. More importantly, the CO formation begins at an ultralow η of 54 mV. These studies demonstrate shape and structure influences of electrocatalysts as well as employed solvent in tuning electrocatalytic activity and selectivity of metal/non-mental catalysts for CO2RR. I also developed a new Ni-doped La(Sr)FeO3-δ as an electrocatalyst for CO2RR at elevated temperatures. To further increase the electrochemical performance of La(Sr)Fe(Ni), the powders were reduced in a tubular furnace in a reducing gas flow, thus forming in situ exsolved Fe-Ni alloy nanospheres on the backbone of LSFN since the catalysts coated with functional metal/alloy nanoparticles can significantly improve the catalytic activity and coking resistance in hydrocarbon fuels. Additionally, I developed an electrocatalyst with in situ exsolved Co-Fe alloy nanoparticles embedded in an active (Pr0.4Sr0.6)3(Fe0.85Mo0.15)2O7 double-layered perovskite backbone, which also acts as a more stable and efficient electrocatalyst to promote CO2RR compared to the Pr0.4Sr0.6Co0.2Fe0.7Mo0.1O3-δ cubic perovskite. Therefore, these newly developed perovskites point to a new direction to develop highly efficient catalysts in the form of the perovskite oxides with uniformly in situ exsolved metal/bimetal nanospheres/nanoparticles.
Language
English
DOI
doi:10.7939/R3ZK56126
Rights
This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for the purpose of private, scholarly or scientific research. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.
Citation for previous publication
Liu S., Tao H., Zeng L., Liu Q., Xu Z., Liu Q., Luo J.-L. Shape-dependent Electrocatalytic Reduction of CO2 to CO on Triangular Silver Nanoplates. Journal of the American Chemical Society, 2017, 139, 2160-2163.Liu S., Liu Q., Luo J.-L. The Excellence of La(Sr)Fe(Ni)O3 as an Active and Efficient Cathode for Direct CO2 Electrochemical Reduction at Elevated Temperatures. Journal of Materials Chemistry A. 2016, 5, 2673-2680.Liu S., Liu Q., Luo J.-L. Highly Stable and Efficient Catalyst with In Situ Exsolved Fe-Ni Alloy Nanospheres Socketed on an Oxygen Deficient Perovskite for Direct CO2 Electrolysis. ACS Catalysis. 2016, 6, 6219-6228.Liu S., Liu Q., Luo J.-L. CO2-to-CO conversion on layered perovskite with in situ exsolved Co-Fe alloy nanoparticles: an active and stable cathode for solid oxide electrolysis cells. Journal of Materials Chemistry A. 2016, 4, 17521-17528.

File Details

Date Uploaded
Date Modified
2017-06-30T21:16:37.837+00:00
Audit Status
Audits have not yet been run on this file.
Characterization
File format: pdf (Portable Document Format)
Mime type: application/pdf
File size: 11018974
Last modified: 2017:11:08 16:27:09-07:00
Filename: Liu_Subiao_201706_PhD.pdf
Original checksum: 90fb358e11c7160226baf42fe8259abc
Well formed: false
Valid: false
Status message: Unexpected error in findFonts java.lang.ClassCastException: edu.harvard.hul.ois.jhove.module.pdf.PdfSimpleObject cannot be cast to edu.harvard.hul.ois.jhove.module.pdf.PdfDictionary offset=6242
Status message: Invalid Annotation list offset=10921093
File language: zh-CN
Activity of users you follow
User Activity Date