Tailored monolith supports for improved ultra-low temperature water-gas shift reaction

Supported ionic liquid-phase (SILP) particulate catalysts consisting of Ru-complexes dissolved in an ionic liquid that is dispersed on a gamma-alumina porous substrate facilitate the water-gas shift (WGS) reaction at ultra-low temperatures. In this work, a screening of different ceramic support materials was performed to design a suitable monolithic support to disperse the SILP system with the objective of scaling up the WGS process efficiently. gamma-Alumina-rich channeled monoliths were developed with the use of natural clays as binders (10 wt% bentonite and 20 wt% sepiolite) with the following properties: i) high volume of mesopores to maximize the catalyst loading and successfully immobilize the ionic liquid-catalyst system via capillary forces, ii) mechanical resistance to withstand the impregnation process and the reaction operating conditions, and iii) surface chemistry compatible with a highly active and selective phase for WGS. The developed monolithic-SILP catalyst demonstrated high stability and long-term WGS performance at 130 degrees C with an average steady-state CO conversion of around 30% after 190 h time-on-stream (TOS) and a conversion of 23% after 320 h TOS. Interestingly, the catalyst activity proved essentially unaffected by variation in the water partial pressure during operation due to accumulation of water in the monolith, thus making the system highly durable.

Automated summary

Supported ionic liquid-phase (SILP) particulate catalysts consisting of Ru-complexes dissolved in an ionic liquid dispersed on a gamma-alumina porous substrate show high stability and long-term performance in the water-gas shift (WGS) reaction, with great potential for industrial application.