CHAPTER 7. SILP and SCILL Catalysis

Abstract

Supported Ionic Liquid Phase (SILP) catalysts and Solid Catalyst with Ionic Liquid Layer (SCILL) both consist of an ionic liquid dispersed as a thin film on the inner surface of a highly porous solid material. In SILP catalysis the ionic liquid film contains a dissolved homogeneous transition metal complex and in this way a macroscopic solid adopts the chemical reactivity of a homogeneous, ligand-controlled catalyst. In SCILL materials the ionic liquid film modifies the catalytic sites of a classical heterogeneous catalyst in a ligand-like manner. In addition, the specific solubility of the IL film adjusts the local feedstock and product concentrations at the active center. Both, SILP and SCILL materials can be handled like classical heterogeneous catalysts and are suitable for classical fixed-bed technologies, a fact that makes transition to technical applications in larger scale very attractive. Our contribution focuses on some common key technical aspects of both SILP and SCILL technologies. The influence of support structure and support surface chemistry on the functionality of the prepared catalysts is highlighted. Optimization of the ionic liquid loading and large scale preparation technologies for these materials are other important aspects of the chapter.