Qi Li

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Project title: The role of Fe in conjunction with N-doping on oxygen electrocatalysis

Supervisor: Dr Christopher R Jones

Content: Oxygen electrocatalysis is crucial in many areas of energy storage and conversion technologies such as fuel cells, electrolysers and metal-air batteries. Most catalysts involved in these technologies are based on precious metals such as Pt or Ir, which are expensive and finite resources. Therefore, it would be extremely advantageous to reduce Pt-loading or even completely replace it with abundant and cheap materials.

A significant amount of research has been dedicated to the design of low-cost and sustainable oxygen electrocatalysts as alternatives for these technologies. Recently, it has been demonstrated that adding Fe within N-doped carbon materials, or other heteroatom-doped carbon frameworks, leads to a significant boost in the electrocatalytic performance in the oxygen reduction reaction (‘ORR’, which happens at the cathode of fuel cells). However, the best chemical and coordination environment for Fe within the carbon materials is unclear, as is the precise mechanism for ORR processes.

Up to now, it is still a challenge to identify the exact number of available active Fe sites at the surface of catalysts. There are mainly three types of Nitrogen in carbon matrix (pyridine-type N atom, pyrrole-type N atom and graphitic-type N atom). It is difficult to control the chemical environment for Fe within carbon materials. In this project, some predesigned Fe-N moieties will be introduced onto the surface of the Carbon Nanotubes. The ORR electrochemistry performance of the synthesized carbon materials will be tested, and the structural properties will also be characterized. By combining the structural properties and ORR electrochemistry performance, we will hopefully be able to explain the mechanisms and identify the contributions of each nitrogen site to the ORR process.

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