LAUSR

1,4-Butanediol can be produced from 1,4-anhydroerythritol over the co-catalysis of monometallic mixture catalysts (ReOx/CeO2 + ReOx/C) in one-pot reduction with H2. The highest yield of 1,4-butanediol reached over 80%, which is similar to the value obtained over ReOx-Au/CeO2 + ReOx/C catalysts. Mixture catalysts of CeO2 + ReOx/C showed almost the same performance, giving 89% yield of 1,4-butanediol. The reactivity trends of possible intermediates suggest that the reaction mechanism over ReOx/CeO2 + ReOx/C catalysts is similar to that over ReOx-Au/CeO2 + ReOx/C: deoxydehydration (DODH) of 1,4-anhydroerythritol to 2,5-dihydrofuran over ReOx species on CeO2 support with the promotion of H2 activation by ReOx/C, isomerization of 2,5-dihydrofuran to 2,3-dihydrofuran catalyzed by ReOx on C support, hydration of 2,3-dihydrofuran catalyzed by C, and hydrogenation to 1,4-butanediol catalyzed by ReOx/C. The activity of ReOx/CeO2 + ReOx/C is higher than that of ReOx-Au/CeO2 + ReOx/C which is probably related to the reducibility of ReOx/C and the move of Re species between supports. The high-valent Re species such as Re7+ on CeO2 and C supports are mobile in the solvent; however, the low-valent Re species including metal Re species have much lower mobility. Metallic Re and cationic low-valent Re species with high reducibility and low mobility can be present on carbon support as a trigger for H2 activation and promoter of the reduction of Re species on CeO2.