Design and synthesis of noble metal nanoparticles embedded in porous Si – A novel approach to enhance transfer efficiency in redox reactions
Research Keywords:Â Energy, Nanotechnology, Environmental Chemistry, Materials Science, Semiconductors
Deadline:Â 1st April 2013. This studentship is available for a 1st October 2013 start.Â
Primary: Dr Yimin Chao (School of Chemistry)
This is a collaborative project between the Energy Materials Lab (UEA) and the Advanced Materials Lab (Fudan) led by Prof Dongyuan Zhao, and co-sponsored by the Fudan Tyndall Centre. Prof Hualong Xu from Fudan is the co-supervisor for this project.
Selective oxidation and hydrogenation is a key technology in the chemical industry, in which highly active and stable catalysts are desired to enhance transfer efficiency and reduce by-products, as a way to enhance energy efficiency and reduce CO2 production. Features of catalyst supports are usually the crucial factors for improving the performance of a catalyst by enhancing the activity of the active species. An ideal support should, at the minimum, possess two essential functions: (1) to maintain high dispersion and stability of the active components, and (2) to facilitate the diffusion of reactants and the accessibility to active sites. Therefore, much effort has focussed on creating new catalyst supports that can provide an anti-sintering property and increase the accessibility to active species.1
Porous Si (pSi) possesses nanoporous holes in its microstructure rendering a large surface to volume ratio. pSi can be fabricated by anodization, in which platinum cathode and silicon wafer anode are immersed in Hydrogen Fluoride (HF) electrolyte. Corrosion of the anode is produced by running electrical current through the cell. It is noted that the running of constant direct current is usually implemented to ensure steady tip-concentration of HF, resulting in a more homogeneous porosity layer. After drying and surface modification to improve the stability, pSi is an ideal candidate to assemble noble metal catalysts. 2
Noble metal nanoparticles can be deposited onto pSi and form an interesting ârocks-in-forestâ structure, which is envisaged to exhibit excellent activity/selectivity/stability in selective oxidation (Ag/Si) or hydrogenation (Pt/Si, Pd/Si) processes.
This project aims to assemble a unique ârock-in-forestâ structure with pSi and selected noble metal nanoparticles, through optimised etching parameters for pSi fabrication, investigating the effect of surface modification on stability of pSi and assembled structure, to achieve high rate and selectivity for conversion of an alcohol to its corresponding aldehyde or the selective hydrogenation of citral.3
A first class UK honours degree, or the equivalent qualifications gained outside the UK, in Chemistry.
This project is specifically funded for international students only. This funding includes full tuition fees and an annual stipend of Â£13,726. Funding is available for 3 years. Home/EU students are still welcome to apply provided they are able to secure their own source of funding.
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