Excess heat evolution from nanocomposite samples under exposure to hydrogen isotope gases

Akira Kitamura, Akito Takahashi, Koh Takahashi, Reiko Seto, Takeshi Hatano, Yasuhiro Iwamura, Takehiko Itoh, Jirohta Kasagi, Masanori Nakamura, Masanobu Uchimura, Hidekazu Takahashi, Shunsuke Sumitomo, Tatsumi Hioki, Tomoyoshi Motohiro, Yuichi Furuyama, Masahiro Kishida, Hideki Matsune

Research output: Contribution to journalArticlepeer-review

18 Citations (Scopus)


Anomalous heat effect by interaction of hydrogen isotope gas and metal nanocomposites supported by zirconia or by silica has been examined. Observed absorption and heat evolution at RT were not too large to be explained by some chemical processes. At elevated temperatures of 200–300 °C, most samples with binary metal nanocomposites produced excess power of 3–24 W lasting for up to several weeks. The excess power was observed not only in the D-Pd·Ni system but also in the H–Pd·Ni system and H–Cu·Ni system, while single-element nanoparticle samples produced no excess power. The Pd/Ni ratio is one of the keys to increase the excess power. The maximum phase-averaged excess heat energy exceeded 270 keV/D, and the integrated excess heat energy reached 100 MJ/mol-M or 90 MJ/mol-H. It is impossible to attribute the excess heat energy to any chemical reaction; it is possibly due to radiation-free nuclear process.

Original languageEnglish
Pages (from-to)16187-16200
Number of pages14
JournalInternational Journal of Hydrogen Energy
Issue number33
Publication statusPublished - Aug 16 2018

All Science Journal Classification (ASJC) codes

  • Renewable Energy, Sustainability and the Environment
  • Fuel Technology
  • Condensed Matter Physics
  • Energy Engineering and Power Technology


Dive into the research topics of 'Excess heat evolution from nanocomposite samples under exposure to hydrogen isotope gases'. Together they form a unique fingerprint.

Cite this