Abstract
Herein we report an easy and facile method for preparation of Tin oxide-doped fluorine. SnO
2
nanoparticles were synthesized using the sol–gel method. The obtained Sn(OH)
4
is calcined at 450 °C then impregnated with different loading 10–55 wt.% of HF as a source of fluoride, followed by calcination at 200, 300, and 400 °C. The particle size of SnO
2
was found to be between 5 and 8 nm. The
S
BET
values and pore size distribution of the F–Sn data were discussed. Examining the surface acidity, confirm that the addition of fluoride ions increases both of the total surface acidity and the ratio of Brønsted to Lewis acid sites. The catalytic activity of the fluoride-tin oxide nanoparticles solid catalysts was investigated through the synthesis of 3,4-dihydropyrimidin-2(1H)-one. 45 F–Sn catalyst calcined at 200 °C has the highest and strongest acid sites (
E
a
= 450.0 mV) that enhance the catalytic activity reaching the maximum yield of (96.5%). The F–Sn catalysts were reused several times with no activity loss.
Highlights
SnO
2
nanocatalyst was doped with different loading of fluoride (10–55 wt. %) and calcined at different temperatures (200, 300, and 400 °C).
The prepared catalysts had the tetragonal cassiterite structure phase of SnO
2
with crystal size between 5 and 8.2 nm.
The sample 45F-Sn calcined at 200 °C has the highest B/L ratio and gives the best yield (96.5%) of 3,4-dihydropyrimidin-2(1H)-one.