Enhancing the reusability of hydroxyapatite by barium modification for efficient isomerization of glucose to fructose in ethanol.

[Display omitted] • Barium modified hydroxyapatite is highly effective for glucose isomerization to fructose in ethanol. • Fructose yield of 35.4% with selectivity up to 93.5% was obtained at glucose loading of 10 wt%. • The catalyst was reused with high recovery rate and ultralow leaching of ions. • The composition, structure and activity of catalyst can be completely restored via calcination. The application of synthetic catalysts to displace costly isomerases for glucose isomerization to fructose has been a long-standing goal in biomass valorization, but current catalysts generally suffer from inferior stability and reusability. Here we show that the combination of barium modified hydroxyapatite (Ba/HAP) as catalyst with ethanol as solvent enables highly efficient and selective isomerization of glucose to fructose, affording fructose yield of 35.4% with selectivity up to 93.5% at high glucose loading (10 wt%). Moreover, the Ba/HAP catalyst was reused with high recovery rate and the leaching of ions was greatly inhibited. The composition, structure and catalytic activity of catalyst can be almost completely restored after calcination. Density functional theory simulations revealed that the formation of relatively stable BaCa 6 (PO 4) 4 O phase is beneficial to the improved catalyst stability. Simultaneously achieving high reaction efficiency and good catalyst reusability in green solvent, our study is an important step towards sustainable catalysis. [ABSTRACT FROM AUTHOR]