Liquid-phase hydrogenation of car☐ylic acid on supported bimetallic RuSn-Alumina catalysts

Abstract Heterogeneous Ru Sn catalysts are effective for the liquid-phase hydrogenation of C O group in car☐ylic acids. Hydrogenation activity was affected by the kind of tin compounds used for the preparation of the Ru Sn catalyst. Bis-tributyl tin oxide ((Bu 3 Sn) 2 O), K 2 SnO 3 and Na 2 SnO 3 were found to be the appropriate materials for the hydrogenation of C O group over the Ru Sn catalysts. The C O hydrogenation activity for the hydrogenation of car☐ylic acids increased with the increasing amount of Sn added whereas, the C C hydrogenation activity decreased. Effect of activation temperature was also studied. The C O hydrogenation activity was increased by calcinating the catalyst precursor, Sn/alumina, before impregnation with Ru solution. The calcination of the Sn/alumina at 973 K was quite effective for the hydrogenation of car☐ylic acids over the resultant Ru Sn/alumina catalysts. The Ru Sn/alumina catalysts reduced at 723 K were also effective for the hydrogenation of car☐ylic acids. We have also studied the hydrogenation in a continuously flowing system. The Ru Sn/alumina catalysts showed high and stable activity under mild conditions in the flowing system.