Effect of silica on the thermal behaviour and ionic conductivity of mixed salt solid acid composites

Norsyahida Mohammad, Abu Bakar Mohamad, Abdul Amir H. Kadhum, Kee Shyuan Loh

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

The effect of adding silica (SiO2) to a mixed-salt solid acid composite, CsH2PO4/NaH2PO4, was studied via conductivity measurements, thermal analyses and X-ray diffraction. The conductivity value of the composites ranged from 1.1 × 10−4 S cm−1 to 7.6 × 10−3 S cm−1 for temperatures from 210 °C to 250 °C, respectively. Adding NaH2PO4 to the composite reduced the conductivity value at 230 °C due to the decomposition of NaH2PO4, which initiated at 210 °C. Dehydration of CsH2PO4 was evident at 230 °C and 270 °C, while the superprotonic phase transition was not observed. Dehydration was detected for NaH2PO4 at temperatures above 210 °C, but a thermally stable composite was produced by mixing it with CsH2PO4 and SiO2. An X-ray diffraction analysis confirmed the existence of solid acid solutions for the composites consisting of NaH2PO4:CsH2PO4 and SiO2:CsH2PO4 in molar ratios of 1:10 to 3:10. The presence of SiO2 partially obstructed the dehydration of the composite, as the diffraction intensity of the dehydration by-product Cs2H2P2O7 decreased at the end of the thermal treatment.

Original languageEnglish
Pages (from-to)896-902
Number of pages7
JournalJournal of Alloys and Compounds
Volume690
DOIs
Publication statusPublished - 5 Jan 2017

Fingerprint

Ionic conductivity
Silicon Dioxide
Salts
Silica
Dehydration
Acids
Composite materials
X ray diffraction analysis
Byproducts
Hot Temperature
Diffraction
Phase transitions
Heat treatment
Decomposition
X ray diffraction
Temperature

Keywords

  • Ionic conductivity
  • Silica
  • Solid acid composite
  • Thermal properties

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry

Cite this

Effect of silica on the thermal behaviour and ionic conductivity of mixed salt solid acid composites. / Mohammad, Norsyahida; Mohamad, Abu Bakar; Kadhum, Abdul Amir H.; Loh, Kee Shyuan.

In: Journal of Alloys and Compounds, Vol. 690, 05.01.2017, p. 896-902.

Research output: Contribution to journalArticle

Mohammad, Norsyahida ; Mohamad, Abu Bakar ; Kadhum, Abdul Amir H. ; Loh, Kee Shyuan. / Effect of silica on the thermal behaviour and ionic conductivity of mixed salt solid acid composites. In: Journal of Alloys and Compounds. 2017 ; Vol. 690. pp. 896-902.
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