Synthesis of Cu-based catalysts for hydrogenolysis of glycerol to 1,2-propanediol with in-situ generated hydrogen

• Published in: Journal of environmental chemical engineering Vol. 9; no. 4; p. 105263
• Main Authors: Mishra, Naveen Kumar, Kumar, Praveen, Srivastava, Vimal Chandra, Štangar, Urška Lavrenčič
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.08.2021
• Subjects: 1,2-propanediol; Catalytic transfer hydrogenation (CTH); Cu-Al-Zn catalysts; Glycerol hydrogenation; 1,2-propanediol; Cu-Al-Zn catalysts; Glycerol hydrogenation; Catalytic transfer hydrogenation (CTH)
• ISSN: 2213-3437; 2213-3437
• DOI: 10.1016/j.jece.2021.105263

This study focuses on the "green" conversion of glycerol to 1,2-propanediol using the Cu-Al-Zn catalyst prepared by the co-precipitation method. Different ratios of (Cu+Zn)/Al were synthesized; the Zn and Al contents were varied while the Cu was kept constant (the Zn/Al ratios were 3:1, 4:1, 5:1, and 6:1). Catalyst characterization using TPD, XRD, and SEM, showed that the synthesized catalysts consisted of hydrotalcite with basic and acidic sites. The basicity of the catalysts was found to be an important criterion for the catalytic transfer hydrogenation, with the basic sites of the catalyst increasing the conversion of glycerol. Copper appeared to have an impressive effect on the C-O/C-C cleavage of glycerol during indirect hydrogenolysis for the synthesis of 1,2-propanediol. A reaction mechanism based on the hydrogenation of ethanol at Cu sites and the formation of intermediates at the basic sites of the catalysts was proposed. [Display omitted] •Synthesis of Cu-Al-Zn catalyst series with different ratios of (Cu+Zn)/Al for tuning of acidity/basicity.•Hydrotalcite-based catalyst shows efficient hydrogen-free conversion of glycerol to 1,2-propanediol.•Catalysts characterized by various characterization techniques.•The basicity of the catalysts is important for catalytic transfer hydrogenation.