Thermal effects on hydrogen storage capacity of Pd/MWCNT nanoparticles deposited at moderate pressure and temperature supercritical carbon dioxide conditions

ERÜNAL E., Ulusal F.

JOURNAL OF SUPERCRITICAL FLUIDS, cilt.157, 2020 (SCI-Expanded) identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 157
  • Basım Tarihi: 2020
  • Doi Numarası: 10.1016/j.supflu.2019.104706
  • Dergi Adı: JOURNAL OF SUPERCRITICAL FLUIDS
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Aerospace Database, Chemical Abstracts Core, Chimica, Communication Abstracts, Compendex, Food Science & Technology Abstracts, INSPEC, Metadex, Civil Engineering Abstracts
  • Anahtar Kelimeler: Hydrogen storage, Multi-walled carbon nanotubes, Thermal effect, Supercritical carbondioxide deposition, Temperature programmed reduction/desorption, PD NANOPARTICLES, PALLADIUM NANOPARTICLES, ALUMINA CATALYSTS, FLUID DEPOSITION, NANOTUBES, SBA-15, PERFORMANCE, SILICA, SOLUBILITY, ADSORPTION
  • Çukurova Üniversitesi Adresli: Evet

Özet

Pd nanoparticles were deposited on MWCNT support for the first time at 80 and under 2500 psi scCO(2) conditions via a bipyridyl precursor in the absence co-solvent. After deposition, the samples were heated under different atmospheres. Then their morphological and hydrogen uptake capacities were investigated. An average particle size between 7-9 nm was estimated via HR-TEM images while intense Pd(111) and Pd(200) sites were detected for all heated samples except no thermally treated one which exhibits PdHx sites. The highest hydrogen adsorption at room temperature was recorded for the samples heated under oxygen. At room temperature, Pd loading amount was found to be effective in means of captured hydrogen. Hence, at higher temperatures, hydrogen uptake of samples treated under nitrogen atmosphere was higher. Additionally, in case of the sample which was not thermally treated, a signal referring to hydrogen release between 200-300 degrees C during reduction was detected. (C) 2019 Elsevier B.V. All rights reserved.