A selective synthesis of 1-phenylethanol and γ-butyrolactone through coupling processes over Cu/MgO catalysts

A novel coupling route highlighting the combination of hydrogenation of acetophenone and dehydrogenation of 1,4-butanediol in vapor phase conditions over Cu–MgO catalyst is highly advantageous in terms of avoiding external pumping of H2 and maintaining the formation of 1-phenylethanol and γ-butyrolactone, the desired products, respectively, in good amounts at atmospheric pressure. Three Cu/MgO catalysts with 5, 10, and 15 wt.% Cu loadings are prepared by impregnation method and characterized by BET surface area, temperature programmed reduction, XRD, N2O pulse chemisorption, transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Among the studied Cu/MgO catalysts, 10 wt.% Cu/MgO catalyst exhibited superior activity with nearly 100% selectivity of PhE and GBL. The higher yields of the products are observed on the 10 wt.% Cu/MgO in single and combined reactions compared to the other two catalysts, it may be due to the higher dispersion, smaller Cu particle size and more number of Cu0/Cu+ species at the surface.

Graphical abstractA novel coupling route highlighting the combination of acetophenone hydrogenation to 1-phenylethanol and 1,4-butanediol dehydrogenation to γ-butyrolactone in vapor phase over Cu/MgO catalysts, wherein, H2 produced from 1,4-butanediol dehydrogenation is effectively utilized in acetophenone hydrogenation rather than from external source and 100% selectivity towards desired products.Figure optionsDownload full-size imageDownload high-quality image (68 K)Download as PowerPoint slideHighlights► In situ production of hydrogen and its in situ utilization. ► Coupling of 1,4-butanediol dehydrogenation and acetophenone hydrogenation is new. ► Selective production of 1-phenylethanol is a potential application. ► The in situ produced hydrogen need not be purified and stored. ► The overall process is economic, safe and environmentally benign.