Synthesis, Characterization, and Biofuel Application of Mesoporous Zirconium Oxophosphates

Abstract

Mesoporous zirconium oxophosphates have been synthesized through the evaporation-induced self-assembly (EISA) method in the presence of an amphiphilic block copolymer, pluronic F127 as template under strongly acidic conditions. The mesophases of the materials were analyzed by using small-angle powder X-ray diffractions and transmission electron microscopic (TEM) image analysis. N2 adsorption−desorption studies showed high surface area (260−312 m2 g−1) and narrow pore size distribution (4.5−5.5 nm) for the materials. NH3-TPD and pyridine-IR analyses suggested the presence of strong Lewis and Brönsted acid sites. These mesoporous materials showed excellent catalytic activity in biodiesel reaction for the effective conversion of the long chain fatty acids to their respective methyl esters. The maximum biodiesel yield was about 91% under optimal reaction conditions. High catalytic activity could be attributed to the large surface area and the presence of large number of acidic sites located at the surface of the materials. The catalysts showed negligible loss of activity after five repetitive cycles.