Descriptor Development for Hydrogen Storage Materials Design: A DFT Case Study

Ying-Cheng Chen^1*, Amita Sihag^1,2, Matthew Stephen Dyer², Hsin-Yi Tiffany Chen¹

¹Department of Engineering and System Science, National Tsing Hua University, Hsinchu, Taiwan
²Department of Chemistry, University of Liverpool, Liverpool, UK

* Presenter:Ying-Cheng Chen, email:yinchengchen@gmail.com

Carbon materials are potential candidates for hydrogen storage due to their low density, stability, durability, and eco-friendly. We attempted to develop an initial quick guess of the hydrogen storage by using four defective graphenes (single vacancy graphene, 5-8-5 divacancy graphene, 555-777 divacancy graphene, and 5555-6-7777 divacancy graphene) with the decoration of one platinum cluster (Pt₄). The occurrence of hydrogen spillover is the major criterion for us to indirectly judge the hydrogen storage capacity. We found that there is a tendency to drive the occurrence of hydrogen spillover on divacancy graphene supported Pt₄ from the metal catalyst to the graphene substrate. Hydrogen spillover prevents the metal catalyst from hydrogen poisoning and lets hydrogen atoms be chemisorbed on the graphene surface. And once interactions between hydrogen-support and metal-support of a carbon material are moderate compared to other carbon materials, hydrogen spillover intends to occur. Thus, we could correlate hydrogen-support and metal-support interactions to their hydrogen spillover occurrence, indirectly predicting their hydrogen storage potential. In short, the DFT calculation results suggest the hydrogen-support and metal-support interactions could be the descriptors to predict the performance of hydrogen storage materials.

Keywords: Density Functional Theory, Hydrogen Storage, Pt, Defective Graphene