Plasmon enhanced glucose photoreforming for arabinose and gas fuel co-production over 3DOM TiO2-Au

Glucose photoreforming provides a promising alternative strategy for biomass valorization. However, the use of harsh environment (high alkalinity or organic solvents) and low product selectivity due to non-selective free radical oxidative cleavage limit their application in large-scale settings. Here, we show photoreforming of glucose to arabinose with high selectivity in water using gold nanoparticles decorated three dimensionally ordered macroporous TiO2 (3DOM TiO2-Au). We demonstrate that the hierarchically porous 3DOM architecture and Au nanoparticles enhance glucose conversion and arabinose selectivity by improving glucose-photocatalysts interaction, electron generation, charge separation, and localized surface plasmon resonance (LSPR) induced light absorption. The 3DOM TiO2-Au produces arabinose via the direct C1-C2 α-scissions mechanism as evidenced by 13C labeled glucose at C1 position. Our experimental results demonstrate the presence of Au(I) is crucial for glucose to arabinose selective conversion. Aside from arabinose production, 3DOM TiO2-Au also generates considerable amount of gas fuels (H2, CH4 and CO) from transient dehydration and hydrogenation reaction of the by-product formic acid. The present work demonstrates a green and promising approach to convert biomass derived feedstocks into value-added chemicals along with gas fuel production.