Highly efficient and stable Au/Mn2O3 catalyst for oxidative cyclization of 1,4-butanediol to γ-butyrolactone

In this work, gold nanopartides deposited on manganese sesquioxide (Mn2O3) showed high activity in the oxidative lactonization of 1,4-butanediol to 'y-butyrolactone with air as the oxidant. On the contrary, nano-sized gold supported on manganese dioxide (MnO2) and manganese oxide (MnO) presented much lower activities. XRD, TEM and XPS characterizations revealed that the superior catalytic performance of Au/Mn2O3 could be ascribed to the highest dispersion of gold particles and unique intrinsic properties of Mn2O3, which possesses the appropriate point of zero charge for deposition precipitation method, the most quantity of oxygen vacancies and the appropriate gold support interaction. AulMn(2)O(3) exhibited selectivity of 100%, which could facilitate the purification of target product from the reaction mixture. Furthermore, the as-prepared Au/Mn2O3 catalyst could be recovered by simple filtration, and used repetitively or preserved for a long period without apparent loss of activity. (C) 2013 Elsevier B.V. All rights reserved.