Developing of CuxSnSO@GO aerogels used as highly efficient catalysts for cellulose transform to lactic acid under the synergy of Cu-Sn thermocatalysis and photocatalysis processes

Biorefinery of cellulose-based materials to obtain high-value products have always been impeded by the energy barrier required for the isomerization from glucose to fructose. Here, a novel CuxSnSO@GO aerogel is synthesized and applied as thermal/photocatalyst for lactic acid (LA) production from cellulose. As a thermalcatalyst, the co-existence of Cu(II) and Sn(IV) show prominent to realize the isomerization of reducing sugars to fructose under mild conditions. Fructose accumulated due to the relatively lagging thermalcatalytic conversion rate would supply for photocatalytic process. As a photocatalyst, the regulated band structure exhibits superior performance for selective cleavage C3-C4 bonds in fructose as well as the subsequent transformation of trioses to LA. The optimal lactic acid yield is about 83.6% at 80 °C and the aerogel shows stable and recyclable characteristics. DFT calculation and scavenging experiments disclosing all activate radicals (·OH, ·O2–, h+) contributed to the selective transformation process and ·O2– was responsible for the main contribution.