LAUSR

Abstract Acetic acid hydrogenation has been carried out over Rh/Al 2 O 3 and RhSn/Al 2 O 3 with various Sn/Rh ratios and different loadings. Metallic Rh, Rh oxides and Sn oxides were detected after reduction of RhSn/Al 2 O 3 at 623 K. Spillover of hydrogen was observed in H 2 desorption process due to the coexistence of metallic Rh and Sn oxides. The addition of Sn improved dissociation of C OH bond and stabilized top adsorption of acetyl species during the adsorption of acetic acid at 548 K. With the introduction of hydrogen, high Sn/Rh ratio suppressed methane production and generated more ethoxy species. High loadings of Sn and Rh can also improve catalytic performance of acetic acid hydrogenation to ethanol. In our experiments, 3Rh5Sn/Al 2 O 3 achieved the selectivity to ethanol of 74% with the corresponding conversion value of about 98%.