Immobilizing Ni (II)-Exchanged Heteropolyacids on Silica as Catalysts for Acid-Catalyzed Esterification Reactions

  • Qiuyun Zhang School of Chemistry and Chemical Engineering, Anshun University, Anshun 561000, Guizhou Province, China; Engineering Technology Center of Control and Remediation of Soil Contamination of Provincial Science & Technology Bureau, Anshun University, Anshun 561000, Guizhou Province, China
  • Dandan Lei School of Chemistry and Chemical Engineering, Anshun University, Anshun 561000, Guizhou Province, China
  • Qianqian Luo School of Chemistry and Chemical Engineering, Anshun University, Anshun 561000, Guizhou Province, China
  • Taoli Deng School of Chemistry and Chemical Engineering, Anshun University, Anshun 561000, Guizhou Province, China
  • Jingsong Cheng School of Chemistry and Chemical Engineering, Anshun University, Anshun 561000, Guizhou Province, China
  • Yutao Zhang Engineering Technology Center of Control and Remediation of Soil Contamination of Provincial Science & Technology Bureau, Anshun University, Anshun 561000, Guizhou Province, China
  • Peihua Ma School of Chemistry and Chemical Engineering, Guizhou University, Guiyang 550025, Guizhou Province, China

Abstract

Biodiesel was synthesized from oleic acid using Ni (II)-exchanged heteropolyacids immobilized on silica (Ni0.5H3SiW / SiO2 ) as a solid acid catalyst. Based on detailed analyses of FT-IR, XRD, TG and SEM, the structural, surface and thermal stability of Ni0.5H3SiW / SiO2 were investigated. Obtained results demonstrated that the Keggin structure was well in the immobilization process and possess a high thermal stability. Various esterification reaction conditions and reusability of catalyst were studied. High oleic acid conversion of 81.4 % was observed at a 1:22 mole ratio (oleic acid: methanol), 3 wt. % catalyst at 70 °C for 4 h. The Ni0.5H3SiW / SiO2 catalyst was reused for several times and presented relatively stable. More interestingly, the kinetic studies revealed the esterification process was compatible with the first order model, and a lower activation energy was obtained in this catalytic system.

Keywords: heteropolyacids, Ni salts of silicotungstic acid, SiO2, esterification, biodiesel
Published online
2019-11-28
How to Cite
Zhang, Q., Lei, D., Luo, Q., Deng, T., Cheng, J., Zhang, Y. and Ma, P. (FIRST) “Immobilizing Ni (II)-Exchanged Heteropolyacids on Silica as Catalysts for Acid-Catalyzed Esterification Reactions”, Periodica Polytechnica Chemical Engineering. doi: https://doi.org/10.3311/PPch.14788.
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Articles