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arXiv · 2206.06638

Hydrogen spillover and storage on graphene with single-site Ti catalysts

Jhih-Wei Chen·Shang-Hsien Hsieh·Sheng-Shong Wong·Ya-Chi Chiu·Hung-Wei Shiu·Chia-Hsin Wang·Yaw-Wen Yang·Yao-Jane Hsu·Domenica Convertino·Camilla Coletti·Stefan Heun·Chia-Hao Chen·Chung-Lin Wu
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Abstract

Hydrogen spillover and storage for single-site metal catalysts, including single-atom catalysts (SACs) and single nanocluster catalysts, have been elucidated for various supports but remain poorly understood for inert carbon supports. Here, we use synchrotron radiation-based methods to investigate the role of single-site Ti catalysts on graphene for hydrogen spillover and storage. Our in-situ angle-resolved photoemission spectra results demonstrate a bandgap opening and the X-ray absorption spectra reveal the formation of C-H bonds, both indicating the partial graphene hydrogenation. With increasing Ti deposition and H2 exposure, the Ti atoms tend to aggregate to form nanocluster catalysts and yield 13.5% sp3-hybridized carbon atoms corresponding to a hydrogen-storage capacity of 1.11 wt% (excluding the weight of the Ti nanoclusters [1]). Our results demonstrate how a simple spillover process at Ti SACs can lead to covalent hydrogen bonding on graphene, thereby providing a strategy for a rational design of carbon-supported single-site catalysts.

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Jhih-Wei Chen, Shang-Hsien Hsieh, Sheng-Shong Wong, Ya-Chi Chiu, Hung-Wei Shiu, Chia-Hsin Wang, Yaw-Wen Yang, Yao-Jane Hsu, Domenica Convertino, Camilla Coletti, Stefan Heun, Chia-Hao Chen, Chung-Lin Wu. 2022-06-14. Hydrogen spillover and storage on graphene with single-site Ti catalysts. https://doi.org/10.1021/acsenergylett.2c00941

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