The effect of the support in the simultaneous hydrogenation of acetophenone and dehydrogenation of 1,4-butanediol was studied using supported (MgO, g-Al 2 O 3 , MgO-Al 2 O 3 and SiO 2 ) copper (10 wt%) catalysts, prepared via impregnation. In this process, acetophenone was transformed to 1-phenylethanol/ ethylbenzene and 1,4-butanediol converted to g-butyrolactone/tetrahydrofuran under a hydrogen-free environment, indicating the major role of the supports. The Cu/MgO catalyst was active and highly selective towards the production of 1-phenylethanol and g-butyrolactone. However, an adverse behaviour was observed over Cu/MgO-Al 2 O 3 . An extraordinary catalytic performance was obtained over Cu/SiO 2 with high selectivity for ethylbenzene (99%) and g-butyrolactone (99%). Contrarily, no hydrogenation of acetophenone was observed over Cu/g-Al 2 O 3 due to the dehydration of 1,4-butanediol, yielding tetrahydrofuran. The main advantage of this process is that no external hydrogen is required for the hydrogenation of acetophenone. Copper dispersion, the reduction behaviour of copper, copper particle size and the acidity and basicity of the catalysts play important roles in the activity. All four catalysts were characterized using BET surface area, N 2 O pulse chemisorption, XRD, XRF, H 2 -TPR, XPS, and TPD of NH 3 /CO 2 to understand our results.

No abstract

This study examined the role of the support material on the coupling of 1,4-butanediol (BDO) dehydrogenation and nitrobenzene (NB) hydrogenation over copper-based catalysts. The catalysts, 10Cu/MgO (10CM), 10Cu/ Al 2 O 3 (10CA), 10Cu/MgO-Al 2 O 3 (10CMA), and 10Cu/SiO 2 (10CS), were prepared using the impregnation method. The coupling reaction results conducted at 250 o C were compared with those of the individual reactions. The individual BDO dehydrogenation to -butyrolactone (GBL) conversion (99%) and hydrogenation of NB to aniline (AN) conversion (85 %) were high over 10CS. In contrast, 10CA produced tetrahydrofuran (THF) as a major product from BDO. Interestingly, the coupling process over the 10CM catalyst produced the best performance in converting NB (65%) to AN (99%) and BDO (85%) to GBL (99%). The superior performance of Cu/MgO in coupling process catalyst is mainly due to the high hydrogen adsorption ability compared to the other catalysts under limited hydrogen environments, which helps retain the active hydrogen on the catalyst surface for a longer time. The characterization of the catalysts showed that a high basic nature and the optimal amount of active copper sites (Cu 0 /Cu 1+ ) are responsible for the best performance of 10CM, followed by 10CS and 10CMA.

The article aims at developing an efficient and stable catalysts for simultaneous hydrogenation of o-chloronitrobenzene to o-chloroaniline and 1,4-butanediol dehydrogenation to γ-butyrolactone. A series of CoO-Cu-MgO catalysts, composed of 10 wt% of copper, various amount of cobalt loadings (1, 5 and 10 wt%) and remaining of MgO were developed by co-precipitation followed by thermal treatment. o-Chloroaniline and γ-butyrolactone were the main products with high yield of 85% and 90%, respectively. The advantage of the coupling process is that the hydrogenation reaction was conducted without external hydrogen, demonstrating minimize the hydrogen consumption known as hydrogen economy route. From N2O characterization results, the high activity of 5CoO-10Cu-MgO was found that it has high amount of Cu species (Cu0/Cu+1) which govern the stable activity and selectivity on time on stream study in presence of cobalt in Cu-MgO.