Hydrogenation of dimethyl malonate to 1, 3-propanediol catalyzed by a Cu/SiO2 catalyst: the reaction network and the effect of Cu+/Cu0 on selectivity. (6th June 2017)

• Record Type: Journal Article
• Authors: Zheng, Sainan; Zhu, Kake; Li, Wei; Ji, Yang
• Is Part Of: New journal of chemistry. Volume 41:Number 13(2017)
• Page Start: 5752
• Page End: 5763
• Publication Date: 2017-06-06
• Subjects: Chemistry -- Periodicals; Chimie -- Périodiques; 540
• DOI: 10.1039/c6nj03960j
• Languages: English
• ISSNs: 1144-0546

Abstract

Abstract : 1, 3-Propanediol was synthesized via the hydrogenation of dimethyl malonate over a Cu/SiO2 catalyst. The reaction network and active sites were revealed for the first time. Abstract : 1, 3-Propanediol, a vital monomer for the manufacture of commodity polytrimethylene-terephthalate, is commercially produced nowadays through either hydration of acrolein or hydroformylation of ethylene oxide. Herein, for the first time, we present the investigation of an alternative route for 1, 3-propanediol production from vapor-phase catalytic hydrogenation of syngas-derived dimethyl malonate on a Cu/SiO2 catalyst. The catalytic reaction network has been disclosed for the Cu/SiO2 catalyst, and the reaction proceeds through sequential hydrogenation with methyl 3-hydroxypropionate as the primary product, which can be further converted into 1, 3-propanediol or methyl propionate. Excessive hydrogenation of 1, 3-propanediol or methyl propionate leads to the formation of n -propanol. Meanwhile, a small amount of dimethyl malonate cracks into methyl acetate. The structural and textural properties of Cu/SiO2 catalysts with varied copper loadings were extensively characterized by X-ray diffraction, Fourier transform infrared spectroscopy, H2 -temperature programmed reduction, X-ray photoelectron spectroscopy, N2 physisorption, CO chemisorption, N2 O titration, and transmission electron microscopy. A correlation of the areal activity to copper components suggests that metallic copper modified by the co-present Cu + species may be the active site for the hydrogenation. The highest 1, 3-propanediol selectivity was achieved on a catalyst with a maximum Cu + /(Cu 0 + Cu + ) ratio of 0.41. The revelation of catalytic networks and insights into the active species can provide guidance for future rational design of catalysts for regioselective hydrogenation of CO bonds in dimethyl malonate.