TY - JOUR
T1 - New Insights on the Formation Process and Thermodynamics of the α-Phase PdH(D)x through Direct Enthalpy Measurement of H(D) Dissolution
AU - Dekura, Shun
AU - Akiba, Hiroshi
AU - Yamamuro, Osamu
AU - Kobayashi, Hirokazu
AU - Maesato, Mitsuhiko
AU - Kitagawa, Hiroshi
N1 - Funding Information:
This work was supported by Core Research for Evolutional Science and Technology (CREST) and ACCEL from the Japan Science and Technology Agency (JST), Grant Number JPMJAC1501, and JSPS KAKENHI, Grant Number 15J01605, Japan.
Publisher Copyright:
© 2020 American Chemical Society.
PY - 2020/4/23
Y1 - 2020/4/23
N2 - The palladium (Pd)-hydrogen (H) system is one of the most famous hydrogen-storage systems. However, the formation process and thermodynamics at the initial stage of hydrogen storage in Pd remain unclear. Here we report the formation process and thermodynamics of the α-phase PdH(D)x (x < 0.03) for the first time through direct measurements of the enthalpy of H and D dissolution, -ΔsolH, at around 303 K, with an accurate adiabatic calorimeter under precisely controllable H2(D2) gas pressure. This is the first observation that three steps are involved in the H(D) dissolution in the α-phase PdH(D)x: the absorption of H(D) into trapping sites, the formation of the α phase, and the β-phase nucleation. The determined values of -ΔsolH were significantly larger than the indirectly estimated previous values. With the accuracy and the wide applicability of our methodology, these new insights may pave the way for future developments in hydrogen chemistry.
AB - The palladium (Pd)-hydrogen (H) system is one of the most famous hydrogen-storage systems. However, the formation process and thermodynamics at the initial stage of hydrogen storage in Pd remain unclear. Here we report the formation process and thermodynamics of the α-phase PdH(D)x (x < 0.03) for the first time through direct measurements of the enthalpy of H and D dissolution, -ΔsolH, at around 303 K, with an accurate adiabatic calorimeter under precisely controllable H2(D2) gas pressure. This is the first observation that three steps are involved in the H(D) dissolution in the α-phase PdH(D)x: the absorption of H(D) into trapping sites, the formation of the α phase, and the β-phase nucleation. The determined values of -ΔsolH were significantly larger than the indirectly estimated previous values. With the accuracy and the wide applicability of our methodology, these new insights may pave the way for future developments in hydrogen chemistry.
UR - http://www.scopus.com/inward/record.url?scp=85083164553&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85083164553&partnerID=8YFLogxK
U2 - 10.1021/acs.jpcc.0c01817
DO - 10.1021/acs.jpcc.0c01817
M3 - Article
AN - SCOPUS:85083164553
VL - 124
SP - 8663
EP - 8668
JO - Journal of Physical Chemistry C
JF - Journal of Physical Chemistry C
SN - 1932-7447
IS - 16
ER -