Acidity and catalytic performance of Yb-doped SO42-/Zr in comparison with SO42-/Zr catalysts synthesized via different preparatory conditions for biodiesel production

作者：Sani Yahaya Muhammad; Alaba Peter Adeniyi; Raji Yahya Aisha Olatope; Aziz A R Abdul; Daud Wan Mohd Ashri Wan^*

来源：Journal of the Taiwan Institute of Chemical Engineers, 2016, 59: 195-204.

DOI：10.1016/j.jtice.2015.07.016

• Catalyst preparation
• Bifunctional catalyst
• Acid activation
• Solid acid catalyst
• Biodiesel

Highly efficient, robust and mesoporous sulfated zirconia, SZ catalysts were prepared by co-precipitation and incipient-wetness routes with sufficient and in-excess acid. The study investigated the effect of pH, precursor type, and concentration, on SZ and compared their acidity and performance with ytterbium-doped SZ toward transesterification. N-2 sorption, elemental analysis, XRD, and ammonia temperature-programmed desorption (NH3-TPD) revealed the properties of the catalytic materials. The specific surface area increases independently of the presence of Ti up to 60.33 m(2)/g, with increasing pH while pore size of the tetragonal crystallites decreases from 37.04 to 6.83 nm. Soaking the material in sufficient 0.5-M H2SO4 produced 37.04 nm S-BET in contrast to 21.21 nm from soaking in excess. Double sulfation ensured sulfate incorporation while moderate precursor amounts enhanced activity of the materials. Interestingly, despite low specific surface area, which was due to short aging period, large mesoporosity, high amount, and dispersion of active sites on Yb-doped SZ, SZr-Ti-Yb-500-4/s ensured remarkable activity. The catalyst converted ca. 99% of used frying oil containing ca. 48 wt. % FFA. Consequently, this highlights the prospect of producing biodiesel at lower cost especially with current dwindling price of crude oil.

• 出版日期2016-2