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Manuscript_Zero-valent Palladium Single-Atoms Catalysts Confined in Black Phosphorus for Efficient Semi-hydrogenation 1029.pdf (1.24 MB)

Zero-valent Palladium Single-Atoms Catalysts Confined in Black Phosphorus for Efficient Semi-hydrogenation

preprint
submitted on 10.12.2020, 04:26 and posted on 11.12.2020, 06:38 by cheng chen, Ou Wei, Yam Kahmeng, Xi Shibo, Zhao Xiaoxu, Chen Si, Jing Li, Lvy Pin, Ma Lu, Xu Haomin, Yu Wei, Fang Hanyan, Yao Chuanhao, Hai Xiao, Ming Joo Koh, Lin Ming, Stephen J. Pennycook, Lu Junling, Du Yonghua, Su Chenliang, Zhang Chun, Jiong Lu

Single-atom catalysts (SACs) represent a new frontier in heterogeneous catalysis due to their remarkable catalytic properties and maximized atomic utilization. However, single atoms often bond to the support with polarized electron density and thus exhibit a high valence state, limiting their catalytic scopes in many chemical transformations. Here, we demonstrated that two-dimensional (2D) black phosphorus (BP) act as giant phosphorus (P) ligand to confine a high density of single atoms (eg, Pd1, Pt1) via atomic layer deposition. Unlike other 2D materials, BP with relatively low electronegativity and buckled structure favors the strong confinement of robust zero-valent palladium SACs in the vacancy site. Metallic Pd1/P SAC shows a highly selective semi-hydrogenation of phenylacetylene towards styrene, outperforming high-valence Pt1/P SAC, and also distinct from metallic Pd nanoparticles that facilitate the formation of fully hydrogenated products. Our DFT calculations reveal that Pd atom forms covalent-like bonding with adjacent P atoms, wherein H atoms tend to adsorb over electron-rich region for the subsequent hydrogenation. Zero-valent Pd in the confined space favors a larger energy gain for the synthesis of partially-hydrogenated product over the fully-hydrogenated one. Our work provides a new route towards the synthesis of zero-valent SACs on BP for a wide range of organic transformations.

Funding

MOE2017-T2-1-056

MOE2019-T2-2-044

History

Email Address of Submitting Author

e0046933@u.nus.edu

Institution

National University of Singapore

Country

Singapore

ORCID For Submitting Author

0000-0001-7875-7079

Declaration of Conflict of Interest

no conflict of interest

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