Synthesis of Guerbet alcohols by self and cross condensation reactions of a variety of fatty alcohols and terpenes over Ni/Cu hydrotalcite-derived mixed oxides W.Y. Hernández a, K. De Vlieger b, P. Van Der Voort a, A. Verberckmoes b (
[email protected]) aCenter for Ordered Materials, Organometallics & Catalysis (COMOC), Ghent University, Krijgslaan 281-S3, 9000 Ghent, Belgium. bIndustrial Catalysis and Adsorption Technology (INCAT), Ghent University, Valentin Vaerwyckweg 1, 9000 Ghent, Belgium. Introduction • Due to the growing importance of renewable feedstocks and use of heterogeneous catalysts the interest in hydrotalcite-derived mixed oxides to perform the Guerbet reaction increased. • The Compound Annual Growth Rate (CAGR) of Guerbet alcohols in 2016-2024 is 5.6%. • Ni/Cu hydrotalcite derived mixed oxides are employed as highly selective, stable and active catalysts in combination with KOH. • The Ni/Cu catalysts are tested in the self and cross condensation on a broad variety of starting alcohols. Hydrotalcite-derived mixed oxides Schematic representation Hydrotalcite-like Mixed Oxides Guerbet Reaction material CalcinationCalcination:: T = 500500°°°°CCCC 1. Dehydrogenation NiNiNi 0,80,80,8-0,8 ---xxxxCuCuCu xxxMgMgMg 5,25,25,2 AlAlAl 222OOO999 444.4. Hydrogenation - 2- e.g. Ni 0,72 Cu 0,08 Mg 5,2 Al 2(OH )16 [CO 3 xH 2O] Ni 0,72 Cu 0,08 Mg 5,2 Al 2O9 2+3. Aldol condensation Hydroxide layer Interlayer (Ni9Cu1HT) (+ dehydration) Materials Characterization Influence of composition Self condensation of 1-Octanol a) XRD patterns obtained for: (((b(bbb) H2-TPR profiles obtained for: Calcined mixed oxides Calcined mixed oxides Full lines: C16 Guerbet alcohol Cu(10) (A); Ni(2.5)Cu(7.5) (B); Ni(5.0)Cu(5.0) (C); Ni(7.5)Cu(2.5) (D); Ni(10) (E) Dashed lines: C16 other products Combining Cu & Ni leads to: Ni/Cu ratio plays significant role in reactivity and selectivity.