Effect of FeOx Modification of Al2O3 on Its Supported Au Catalyst for Hydrogenation of 5 Hydroxymethylfurfural
To enhance the hydrogenation activity of alumina supported Au (Au/Al2O3) catalyst for selective hydrogenation of 5 hydroxymethylfurfural (HMF) an important biomass derived aldehyde, Al2O3 support was modified with iron oxide (FeOx) The apparent catalytic activity of the FeOx/Al2O3 supported Au (Au/FeOx/Al2O3) catalysts increased as an increase of Fe loading up to 10 wt (3 4 times higher than Au/Al2O3) When the Fe loading was more than 10 wt the apparent catalytic activity decreased, and Au/a Fe2O3 showed much lower activity than Au/Al2O3. The Fe K edge X ray absorption fine structure (XAFS) spectra and the atomic scale observation using aberration corrected scanning transmission electron microscopy (Cs STEM) suggested positive and negative effects of FeOx support. As the positive effect, FeOx promotes formation of Au clusters by reduction of Au single atoms having low or no catalytic activity for the hydrogenation. On the other hand, as the negative effect, FeOx, more specifically, large a Fe2O3,