SBA-15 supported ionic liquid phase (SILP) with H2PW12O40- for the hydrolytic catalysis of red macroalgal biomass to sugars

A supported ionic liquid phase (SILP) catalyst for biomass hydrolysis was prepared via immobilization of an acidic ionic liquid (IL) with a phosphotungstic counter-anion H2PW12O40- (HPW) on ordered mesoporous silica (SBA-15). Characterization results from XRD, N-2 physisorption, FT-IR, TGA and SEM/TEM image analyses confirmed the successful preparation of the SILP catalyst (SBA-IL-HPW). Meanwhile, its catalytic performance was evaluated in terms of sugar production from the hydrolysis of different biomasses in water. Under optimal hydrolysis conditions, SBA-IL-HPW yielded 73% D-galactose from agarose and 58% D-glucose from cellobiose. Moreover, SBA-IL-HPW effectively hydrolyzed the red macroalgae G. amansii as it afforded 55% total reducing sugar and 38% D-galactose yields. SBA-IL-HPW was easily separated from the hydrolysates after reaction and was re-used five times without significant loss of activity. Overall findings reveal the potential of SBA-IL-HPW as a durable, environmentally benign catalyst for sugar production from renewable resources.