Project Leader: Prof. Qiang Fu

Supported by Natural Science Foundation of China(面上项目)

Key Words: Interface catalysis; Graphene; Surface chemistry; Nanocatalysis; Dynamic characterization

Abstract: Carbon nanotubes have 1-dimensional (1D) hollow structures and, thus, can be used as nanoreactors for many reactions. Due to the small size (tens of nm) of the hollow space and unique electronic structure of the graphene walls, enhanced catalytic performance may be observed for reactions occurring inside of the carbon nanotubes. It is known that 2D nanospace forms between graphene overlayers and substrates. We have observed that metal atoms or gaseous molecules can be accommodated in the 2D space via an intercalation process. The distance between graphene and substrate typically falls within 1 nm and, moreover, graphene has unique electronic structure at Fermi level. It is expected that adsorbates confined underneath graphene may present novel physical and chemical properties, which, however, have not yet been addressed. In the present project, epitaxial graphene structures are to be grown on metals via chemical vapor deposition (CVD) or surface segregation to obtain the model surfaces, e.g. graphene/Ru(0001), graphene/Pt(111), and graphene/Co(0001). Intercalation of metal atoms and gaseous molecules at the graphene/metal interfaces will be studied by various surface techniques including STM, XPS, UPS, PEEM, and LEEM. The surface reactions occurring at the graphene/metal interfaces can be monitored in-situ by UPS or PEEM. Based on the in-situ and dynamic surface studies, the confinement effect of the graphene "blanket" on the surface chemistry and reactions below will be derived. Furthermore, the basic understanding from the model systems will be extended to the real catalytic systems. Metal@graphene "core-shell" nanoparticles will be synthesized by deposition of monolayer carbon structures on metal nanoparticles. Alternatively, metal or metal oxide nanoparticles can be intercalated into graphite microcrystals, producing graphene/metal/graphene "sandwich" structures. The atomic structure and electronic properties of the graphene-covered or graphene-confined catalysts will be studied by TEM, EELS, XAS, and UPS. Catalytic reactions at gas-solid interfaces, e.g. low temperature catalytic oxidation, ammonia synthesis, and oxygen reduction reaction are conducted over the graphene confined catalysts, which is monitored by gas chromatography (GC) and mass spectrometer (MS). Through the research efforts from both model systems and real catalysts, we attempt to explore the chemistry under graphene. It is expected to see that surface reactions can be controlled by making use of confinement effect of the graphene cover.

Project No.: 21373208

Publication:

1. Yanhong Zhang, Mingming Wei, Qiang Fu*, Xinhe Bao
Oxygen intercalation under hexagonal boron nitride (h-BN) on Pt(111)
Sci. Bull., 60(2015)(18)1572-1579

2. Mingming Wei, Qiang Fu, Yang Yang, Wei Wei, Ethan Crumlin, Hendrik Bluhm, Xinhe Bao
Modulation of Surface Chemistry of CO on Ni(111) by Surface Graphene and Carbidic Carbon
J. Phys. Chem. C, 119(2015)13590-13597

3. Qiang Fu*, Xinhe Bao
Catalysis over metal surface under graphitic cover
Chin. J. Catal., 36(2015)517-519

4. Yanhong Zhang, Xuefei Weng, Huan Li, Haobo Li, Mingming Wei, Jianping Xiao, Zhi Liu, Mingshu Chen*, Qiang Fu*, and Xinhe Bao
Hexagonal Boron Nitride Cover on Pt(111): A New Route to Tune MoleculeMetal Interaction and Metal-Catalyzed Reactions
Nano Letters, 15(2015)3616−3623

5. Yang Yang, Qiang Fu*, Mingming Wei, Hendrik Bluhm, Xinhe Bao*
Stability of BN/metal interfaces in gaseous atmosphere
Nano Research, 8(2015)(1)227-237

6. Aiyi Dong, Qiang Fu, Mingming Wei, Yun Liu, Yanxiao Ning, Fan Yang, Hendrik Bluhm, Xinhe Bao
Facile oxygen intercalation of full layer graphene grown on Ru(0001) under ambient conditions
Surf. Sci., 634(2015)37-43