Posted November 14, 2017 by Rino Rakhmata Mukti, Dr. rer.nat in Guest Seminar

Design of “Intercalation Catalysts” by Use of Anion-exchangeable Layered Ni-Zn Hydroxy Double Salt

Prof. Yoshimasa Amano
Chiba University, Department of Applied Chemistry & Biotechnology, Japan


Layered hydroxy double salts (HDSs), which consist of positively charged layers and exchangeable interlayer anions, have also received considerable interest as anion-exchangeable layered compounds. Compounds in the HDS family follow the general formula MA2+1–xMB2+2xAn–2x/n(OH)2·mH2O (0.15 < x < 0.25), where MA2+ and MB2+ are divalent metal cations such as Zn2+, Cu2+, Co2+, or Ni2+, and An– represents various interlayer anions. The anionic guests that can be used range from simple inorganic anions (NO3–, ClO4–, Cl–, MnO4–, SO42–, etc.) to anionic metal complexes to organic anions including drugs and dyes. It can be considered that HDSs are also powerful candidates for advanced nanoscaled catalysts or catalyst supports that allow for control over the location of the catalytically active metal species. We have recently developed novel heterogeneous intercalation catalysts based on Ni–Zn HDS (NiZn), Ni0.63Zn0.37(CH3COO)0.37(OH)2·1.93H2O, as heterogeneous base catalysts and/or hosts for catalytically active anions. For the Brønsted base catalyst, the butyrate-intercalated NiZn catalyst, C3H7COO–/NiZn, was able to promote Knoevenagel condensation reaction and enone epoxidation with hydrogen peroxide. In particular, a monomeric transition metal hydroxide complex such as [Pd(OH)4]2–, [(D-valine)Pd(OH)2]–, or [Rh(OH)6]3– was also able to be intercalated into NiZn interlayers by simple anion-exchange. Some liquid-phase organic transformations, for example aerobic alcohol oxidation and hydrophenylation of enones or internal alkynes were achieved in the presence of these well-defined intercalation catalysts. Selected Publications T. Hara, N. Fujita, N. Ichikuni, K. Wilson, A. F. Lee, S. Shimazu, Catal. Sci. Technol., 6, 863-868 (2016). T. Hara, J. Kurihara, N. Ichikuni, S. Shimazu, Catal. Sci. Technol., 5, 578-583 (2015). T. Hara, N. Fujita, N. Ichikuni, K. Wilson, A. F. Lee, S. Shimazu, ACS Catal., 4, 4040-4046 (2014). T. Hara, J. Sawada, Y. Nakamura, N. Ichikuni, S. Shimazu, Catal. Sci. Technol., 1, 1376-1382 (2011). T. Hara, J Kurihara, N. Ichikuni, S. Shimazu, Chem. Lett., 39, 304-305 (2010). T. Hara, M. Ishikawa, J. Sawada, N. Ichikuni, S. Shimazu, Green Chem., 11, 2034-2040 (2009).