Acceptor-less dehydrogenation of alcohols using supported Cu catalysts prepared by one-step NaBH4 reduction

SSCI-VIDE+CDURABLE+LRN:LDJ:NPRNational audienceAcceptor-less alcohol dehydrogenation (AAD) is a green and atom-efficient process for the direct production of carbonyl compounds from alcohols releasing molecular H2. Unlike catalytic oxidation, this process does not require the use of toxic reagents and over-oxidation is avoided. AAD, in addition to being advantageous for the synthesis of aldehydes, ketones, amides, and esters through dehydrogenative coupling, has potential for cyclic hydrogenation-dehydrogenation reactions as a H2 storage mechanism [1]. The development of a heterogeneous stable, recyclable and cost-effective catalyst that enables large-scale industrial applications is vital [2]. Cu-based catalysts, a more abundant and economical option than noble metals, have presented remarkable results in the dehydrogenation of secondary alcohols and diols [3]. However, there is still room for maximizing activity and selectivity.In this work, Cu-catalysts have been synthesized on three different supports (C, TiO2, ZrO2,) by one-step NaBH4 reduction method. Catalysts were characterized by several techniques including XRD, ICP, N2 physisorption and N2O chemisorption. Acceptor-less dehydrogenation reactions of 2-octanol and 1,2-octanediol were conducted in semi-bath reactor at 145 °C, with constant flow of inert gases. Liquid samples were analyzed by gas chromatography analysis with FID detector. Spent catalysts were characterized by the same techniques as those used for freshly ones to establish a correlation catalysts structure-stability/reaction outcome.References 1.Catal. Sci. Technol., 2018, 8, 3010-30142.Nat. Commun., 2021, 12, 51003.Catal. Commun., 2021, 148, 10617