Synthesizing Single Atom, Monometallic and Bimetallic, Fenton-like, Cobalt-based Catalysts on Silica Support for Advanced Oxidation Processes

Abstract

Clean water is essential for human health and environment. However, the presence of contaminants including dyes and antibiotics has impacted the water quality. This has resulted in the need for wastewater treatment facilities to develop technologies that are efficient in removing these contaminants.

This thesis presents a novel catalyst that uses advanced oxidation processes (AOPs), particularly Fenton-like reactions that can achieve high efficiency for the removal of contaminants from wastewater. Heterogeneous Fenton catalysts offer benefits such as easy recovery and excellent reusability performance but still face challenges including instability and secondary contamination.

Chapter 1 presents the project background and thesis structure. Chapter 2 discusses the different wastewater treatment processes, with a focus on AOPs and Fenton catalysts. Different research gaps have been identified including poor catalyst dispersion, leaching of metal species, pH sensitive, and unclear optimal metal ratios.

Chapter 3 shows the procedure used to synthesize the catalysts and carry out the degradation tests. Chapter 4 reports the strategy used to synthesize cobalt-based single atom catalyst on silica and the results showed excellent dispersion, achieving 16.3 wt.% cobalt loading along with superior degradation performance.

Chapter 5 compares the performance of monometallic and bimetallic catalysts. CoCeSiES40 achieved the highest TCH removal and showed better reusability performance than monometallic CoSiES40 catalyst. Chapter 6 focuses on optimizing the cobalt-cerium ratio; CoCe1Si3 was found to be the best as it removed 82% TCH and the catalyst showed a high radical production along with excellent element dispersion.

Chapter 7 shows the techno-economic analysis. The cost of the bimetallic catalyst CoCe1Si3 was calculated to be AUD 9.06/g and it was found to be competitive with other commercial catalysts. Chapter 8 concludes the thesis and suggests future directions.