Mesoporous Heteropolyacid Nanorods for Heterogeneous Catalysis in Polysaccharide Conversion

Mesoporous heteropolyacid (HPA) nanorods having a composition of [C16H33N(CH3)3]xH3-xPW12O40 ((CTA)xH3-xPW, x = 1, 2, and 3) were synthesized by surfactant encapsulation and were evaluated for their catalytic activity in cellulose hydrolysis. The (CTA)H2PW nanorods were found to be most active with 57.2% yield of 5-hydroxymethylfurfural (5-HMF) at ~100% conversion in water/methyl isobutyl ketone (MIBK) biphase, which was higher than (CTA)H2PW nanosphere at 140 °C for 11 h. The yields of 5-HMF and glucose were obtained as 4.5% and 54.3% at 160 °C for 8 h in water system, respectively. (CTA)H2PW nanorods showed higher tolerance to such feedstocks as lignocellulose, i.e. corn straw with 19.8% and 8.3% yields for glucose and xylose at 35.4% conversion in water. Moreover, (CTA)H2PW nanorods showed higher stability and long duration with ten times reuse. (CTA)H2PW nanorods presented higher efficiency and reusability in conversion of cellulosic biomass.