Hydrogen Storage Mechanisms of Defective Graphene Supported Pt₄—A DFT 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

In our work, we tried to find the descriptors for measuring the hydrogen storage capacity of materials. Since the surface of carbon materials can physisorb hydrogen molecules and chemisorb hydrogen atoms dissociated by catalysts, carbon materials have great potential for increasing hydrogen storage capacity. Carbon materials are also stable, durable, cheap and eco-friendly, these properties make them desired candidates of hydrogen storage materials. Herein, we built models composed of a Pt₄ catalyst and different defective graphene substrates to find the descriptors for hydrogen storage capacity. We found that di-vacancy graphene supported Pt₄ has phenomena of hydrogen spillover from metal catalyst to graphene substrate. Hydrogen spillover prevents metal catalysts from hydrogen poisoning and lets hydrogen atoms be chemisorbed on graphene surface. The descriptors we found were that once interactions between hydrogen-support and metal-support of a specific material are moderate comparing to others, it will have higher hydrogen spillover capability which can prevent transition metal catalyst from hydrogen poisoning and let hydrogen atoms being chemisorbed by the substrate.

Keywords: DFT, Hydrogen Spillover, Pt, Defective Graphene Surfaces, Energy and Green Materials