Iron (II) impregnated double-shelled hollow mesoporous silica as acid-base bifunctional catalyst for the conversion of low-quality oil to methyl esters

Research output: Contribution to journalArticlepeer-review


  • Stefanus Kevin Suryajaya
  • Yohanes Ricky Mulyono
  • Shella Permatasari Santoso
  • Maria Yuliana
  • Alfin Kurniawan
  • Aning Ayucitra
  • Sandy Budi Hartono
  • Felycia Edi Soetaredjo
  • Suryadi Ismadji

Colleges, School and Institutes

External organisations

  • Widya Mandala Surabaya Catholic University
  • National Taiwan University of Science and Technology
  • National Sun Yat-sen University
  • Department of Mechanical Engineering


To promote the use of low-quality oils in producing biodiesel, a bifunctional acid-base catalyst Fe/DS-HMS-NH2 is fabricated using the two-step condensation technique. The obtained Fe/DS-HMS-NH2 is of a doubled shell structure in spherical shape with a uniform size of 156 nm. Its hollow core (with a diameter of 86 nm) and two spatial shells with different active sites enables the esterification and transesterification reactions to be accomplished in a one-pot synthesis. The influences of four independent reaction variables on the yield of fatty acid methyl esters YF was studied, including catalyst loading mc, reaction time t, reaction temperature T, and the methanol to degummed palm oil mass ratio rm/o. The highest yield was obtained at 85.36% (w/w) when mc = 6% (w/w), t = 4.5 h, T = 60 °C, and rm/o = 6:1. The Fe/DS-HMS-NH2 shows a good recyclability with YF > 80% (w/w) up to three reaction cycles.

Bibliographic note

Funding Information: The authors acknowledge the funding supports from Widya Mandala Catholic University Surabaya and World Class Research Program, Indonesian Ministry of Research and Technology , through the research grant no. 2263/WM01/N/2020 and 130B/WM01.5/N/2020 , respectively. We also thank Professor Chun-Hu Chen, National Sun Yat Sen University, and Taiwan Tech (National Taiwan University of Science and Technology) for providing the facility for the catalyst characterizations. Publisher Copyright: © 2021 Elsevier Ltd Copyright: Copyright 2021 Elsevier B.V., All rights reserved.


Original languageEnglish
Pages (from-to)1166-1174
Number of pages9
JournalRenewable Energy
Publication statusPublished - May 2021


  • Amine functionalization, Bifunctional catalyst, Biodiesel, Hollow mesoporous silica, Iron impregnation, Renewable energy