Hybrid catalysts were prepared by anchoring covalently an Rh diamine complex in two very different structured carbon materials: a ceramic monolith coated with carbon nanofibres and a mesoporous carbon xerogel. The morphology of these catalysts allows an easy separation from the reaction media. The obtained catalysts are noticeably more active than the homogeneous Rh complex and they are stable against leaching. After a first use, a partial reduction of the Rh complex takes place and nanometric Rh particles are developed, which increases the catalyst activity. The catalyst prepared with the ceramic monolith coated with carbon fibres shows noteworthy advantages like easy handling, immediate recovery and removal from the reaction media, and good mechanical strength.

The authors thank the financial support through public projects of reference: MAT2012-32832 and PROMETEO/II/2014/010.

Peer reviewed