(Invited) Design of Plasmonic Catalysts Efficient H2 Production from Hydrogen Storage Molecules

Tuesday, 3 October 2017: 11:00
National Harbor 6 (Gaylord National Resort and Convention Center)
H. Yamashita, K. Mori, Y. Kuwahara, H. Cheng, M. Wen, P. Verma, and H. Yin (Osaka University)
Nanostructured plasmonic noble metals such as Au and Ag are attractive materials that strongly absorb visible light owing to their localized surface plasmon resonance (LSPR). [1-6] Up to now, the search for efficient and safe hydrogen storage materials is of crucial significance. Ammonia borane (AB: NH3BH3) and formic acid (FA) with high hydrogen content are attractive chemical hydrogen storage candidates. In this study, we demonstrated that the plasmonic nanostructures, including color-controlled Ag nanoparticles (NPs), novel MoO3-x nanosheets, and core-shell Au@Pd NPs on Metal organic frameworks (MOFs) was used as efficient catalysts under visible light for H2production from these hydrogen storage molecules.

The Ag NPs were prepared on SBA-15 mesoporous silica by microwave-assisted alcohol reduction in the presence or absence of sodium laurate. MoO3-x nanosheets were prepared by oxidizing metal molybdenum powders with H2O2 followed by the solvothermal treatments in ethanol. The catalytic performances were investigated for dehydrogenation of AB in aqueous suspensions with plasmonic catalysts. The activity for H2 production was greatly enhanced by the visible light irradiation induced by LSPR specially on the rod type Ag NPs with lager aspect ratio. Plasmonic semiconductors is another novel category with low resistive loss and earth abundance. By a facile nonaqueous access, MoO3-x nanosheets with tunable LSPR from visible light to near infrared were prepared. Under visible light irradiation, such plasmonic MoO3-x nanosheets displayed dramatically enhanced H2 production rate from AB. Furthermore, a synergistic catalysis of plasmonic Au@Pd NPs supported on titanium doped zirconium based amine-functionalized MOF(UiO-66(Zr100-xTix)) was observed for boosting H2 production from FA. The electronically promoted Pd by the charge transfer arising from the difference in work function of Pd and Au metals and the LSPR effect of Au play a crucial role in achieving high catalytic activity for H2production from FA.

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