A model system approach to understanding heteroatom-doped graphene electrocatalysts

研究问题：杂原子掺杂的石墨烯正在成为一类新的电催化剂，作为目前最先进的地球丰富的替代品，显示出巨大的前景。目前这些催化剂发展的瓶颈是对其结构，表面化学和催化机制的理解不足。部分原因是由于它们的结构复杂性，传统的掺杂工艺（在石墨烯生长期间添加含有杂原子的前体气体）导致随机分布的杂原子，这些杂原子可以位于几个不等价的化学环境中。这种无序使得很难理解化学上不同的掺杂剂原子的相对活性以及掺杂剂密度和掺杂剂-掺杂剂相互作用的作用。方法：在这个项目中，我们将探索不同的方法来生产高度有序的，高质量的杂原子掺杂的石墨烯，然后使用扫描隧道显微镜和X射线光电子能谱的组合在原子尺度上对所得的石墨烯进行表征（参见参考文献对2D氧化物材料的类似研究）。这些信息，然后将相关的电化学测试，以获得一个新的水平的机械理解这些有前途的催化materials.新奇：模型系统的方法：通过生产一个明确的模型系统，通过CVD生长的石墨烯，我们打算能够直接相关的电化学活性，以特定的表面物种。这是一种新的方法，可广泛适用于其他电催化剂和能源材料。

Research Question:Heteroatom-doped graphene are emerging as a new class of electrocatalysts which show great promise as earth-abundant replacements for the current state-of-the-art.The current bottleneck for development of these catalysts is a poor understanding of their structure, surface chemistry and catalytic mechanisms. Part of this is due to their structural complexity, the conventional doping process (adding in a precursor gas which contains the heteroatoms during growth of the graphene) results in randomly distributed heteroatoms which can sit in several inequivalent chemical environments. This disorder makes it very difficult to understand the relative activities of chemically different dopant atoms and the roles of dopant density and dopant-dopant interactions. Approach:In this project we will explore different methodologies to produce highly-ordered, high quality heteroatom-doped graphene and then characterise the resultant graphene on the atomic scale using a combination of Scanning Tunnelling Microscopy and X-Ray Photoelectron Spectroscopy (see references for a similar study on 2D oxide materials). This information will then be correlated to electrochemical testing to gain a new level of mechanistic understanding of these promising catalytic materials.Novelty:Model system approach: By producing a well-defined model system via CVD grown graphene we intend to be able to directly correlate electrochemical activity to specific surface species. This is a novel approach which could be broadly applicable to other electrocatalysts and energy materials.