Robustly supported rhodium nanoclusters: synthesis and application in selective hydrogenation of lignin derived phenolic compounds

Abstract

The stabilization of small rhodium nanoclusters (NCs) in a polymer derived silicon carbonitride (SiCN) matrix has been reported to generate highly robust and active solid catalysts for the selective hydrogenation of phenolic compounds. An aminopyridinato Rh complex was used to modify a preceramic polymer (HTT 1800) followed by its pyrolysis at 1100 °C to afford small Rh NCs nicely dispersed over dense SiCN ceramic. For the synthesis of porous catalysts containing Rh NCs, microphase separation (followed by pyrolysis) of a diblock copolymer of HTT 1800 with hydroxy-polyethylene (PE-OH) was used. Both catalysts exhibit high activity in the hydrogenation of substituted phenols at room temperature and under low hydrogen pressure. The catalysts remained highly active and selective for six consecutive catalytic runs.