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Yasuda, Satoshi; Matsushima, Hisayoshi*; Harada, Kenji*; Tanii, Risako*; Terasawa, Tomoo; Yano, Masahiro; Asaoka, Hidehito; Gueriba, J. S.*; Di
o, W. A.*; Fukutani, Katsuyuki
ACS Nano, 16(9), p.14362 - 14369, 2022/09
Times Cited Count：12 Percentile：85.62(Chemistry, Multidisciplinary)The fabrication of hydrogen isotope enrichment system is essential for the development of industrial, medical, life science, and nuclear fusion fields, therefore alternative enrichment techniques with high separation factor and economic feasibility have been still explored. Herein, we report the fabrication of heterogeneous electrode with layered structures consisting of palladium and graphene layers for polymer electrolyte membrane electrochemical hydrogen pumping for the hydrogen isotope enrichment. We demonstrated significant bias voltage dependence of hydrogen/deuterium (H/D) separation ability and its high H/D at lower bias voltage. Theoretical analysis also demonstrated that the observed high H/D at low bias voltage stems from hydrogen isotopes tunneling through atomically-thick graphene during the electrochemical reaction, and the bias dependent H/D results in a transition from the quantum tunneling regime to classical over- barrier regime for hydrogen isotopes transfer via the graphene. These findings provide new insight for a novel economical methodology of efficient hydrogen isotope enrichment.
Yasuda, Satoshi; Matsushima, Hisayoshi*; Asaoka, Hidehito; Fukutani, Katsuyuki
no journal, ,
We evaluated H/D separation factor of graphene-palladium electrode in hydrogen pumping cell. We revealed that in case of palladium electrode, the separation factor hardly increases while the factor significantly increased for graphene-palladium electrode.
Yasuda, Satoshi; Matsushima, Hisayoshi*; Asaoka, Hidehito; Fukutani, Katsuyuki*
no journal, ,
no abstracts in English
Yasuda, Satoshi; Matsushima, Hisayoshi*; Asaoka, Hidehito; Gueriba, J. S.*; Dio, W. A.*; Fukutani, Katsuyuki*
no journal, ,
In this study, we fabricate heterogeneous electrocatalysts with layered structures consisting of the graphene and palladium layer of the polymer electrolyte membranes electrochemical hydrogen pumping (PEM-ECHP) for an efficient enrichment of hydrogen isotope gas. Mass spectroscopic analysis combined with PEM-ECHP system demonstrated that the PdGr layered electrocatalyst shows significant bias voltage dependence of the separation ability, and high H/D selective ability (H/D= 
25 with current density of 5 mA cm
at room temperature) is achieved at low bias, which is the highest value for the conventional separation methods. Theoretical analysis also confirmed that potential induced quantum to classical transition for proton transfer via graphene plays key role in appearance of the observed trend with the high separation ability.
Yasuda, Satoshi; Matsushima, Hisayoshi*; Terasawa, Tomoo; Yano, Masahiro; Asaoka, Hidehito; Gueriba, J.*; Dio, W.*; Fukutani, Katsuyuki
no journal, ,
We fabricated heterogeneous electrode with layered structures consisting of palladium and graphene layers and reported D2 enrichment from hydrogen and deuterium mixture gas using polymer electrolyte membrane electrochemical hydrogen pumping used the fabricated electrode. Mass spectroscopic analysis demonstrated significant bias voltage dependence of hydrogen/deuterium (H/D) separation ability and the H/D value decreases as the bias voltage increases. Theoretical analysis showed that the observed high H/D at low bias voltage stems from hydrogen isotopes tunneling through atomically-thick graphene during the electrochemical reaction, and the bias dependent H/D results in a transition from the quantum tunneling regime to classical over- barrier regime for hydrogen isotopes transfer via the graphene. These findings provide new insight for a novel economical methodology of efficient hydrogen isotope enrichment.
Yasuda, Satoshi; Matsushima, Hisayoshi*; Yano, Masahiro; Terasawa, Tomoo; Asaoka, Hidehito; Jessiel, G.*; Wilson, D.*; Fukutani, Katsuyuki
no journal, ,
In this study, hydrogen isotope separation ability of graphene was investigated by using electrochemical and theoretical approaches. We found that graphene exhibits high separation ability (H/D) and its bias dependence, and theoretical analysis showed that bias dependence of H/D results from a transition from the quantum tunneling regime to the classical over barrier regime for hydrogen isotopes transfer through the graphene. The findings will help us understand the origin of the isotope separation ability of graphene discussed so far and contribute to developing an economical hydrogen isotope enrichment system using two-dimensional materials.
Kozuka, Shohei*; Saito, Junichi; Ueda, Mikito*; Matsushima, Hisayoshi*
no journal, ,
no abstracts in English
