Effect of Catalyst Size on Hydrogen Storage Capacity of Pt

The experimental clue coming from SAXS measurement and our hydrogen storage capacity study shows that the impregnated Pt nanoparticles of ∼1 nm in s...
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Effect of Catalyst Size on Hydrogen Storage Capacity of Pt-Impregnated Active Carbon via Spillover Cheng-Si Tsao,*,†,§ Yi-Ren Tzeng,† Ming-Sheng Yu,† Cheng-Yu Wang,† Huan-Hsiung Tseng,† Tsui-Yun Chung,† Hsiu-Chu Wu,† Takahiro Yamamoto,‡ Katsumi Kaneko,‡ and Sow-Hsin Chen§ † Institute of Nuclear Energy Research, Longtan, Taoyuan 32546, Taiwan, ‡Department of Chemistry, Chiba University, Chiba 263-8522, Japan, and §Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139

ABSTRACT There are two regimes that exhibit two distinctive behaviors of spillover. The present study used small-angle X-ray scattering (SAXS) to measure size distribution of Pt nanoparticles in the bulk Pt-impregnated active carbon sample. The peak position of the size distribution as determined by SAXS turns out to be at ∼1 nm, which is rarely discussed in this field. SAXS technique is complementary to the other characterization methods. The experimental clue coming from SAXS measurement and our hydrogen storage capacity study shows that the impregnated Pt nanoparticles of ∼1 nm in size can enhance the hydrogen spillover effect. It can significantly increase the room temperature hydrogen uptake compared to currently studied similar systems. The mass loading of catalyst is not a critical factor. Tuning the pore-confined Pt sizes (