The coupling process of dehydrogenation of 1,4-butanediol and hydrogenation of dimethyl maleate over CuO/SiO₂ catalysts to produce one important fine chemical γ-butyrolactone was carried out in a continuous fixed bed reactor under atmospheric pressure. Compared to the conventional reaction process, the activities of catalysts for hydrogenation of dimethyl maleate and dehydrogenation of 1,4-butanediol were enhanced through the coupling process. Under optimum reaction conditions, the conversion of 1,4-butanediol and dimethyl maleate reached 100%, and the selectivity of γ-butyrolactone was 98%. The results of XRD and TPR indicated that the optimized loading weight of CuO was about w＝21%, which is in accordance with the monolayer dispersion threshold value. The active sites were Cu⁰, the proportion of congregated CuO were increased dramatically as CuO loading weight was higher than 21%.

Key words: 1,4-butanediol, dimethyl maleate, γ-butyrolactone, coupling process, CuO/SiO₂