Metal complex hybrid composites based on fullerene-bearing porous polycarbazole for H2, CO2 and CH4 uptake and heterogeneous hydrogenation catalysis

Abstract

Porous polymers with permanent porous structures, considerable reactive sites, high specific surface areas as well as good stability have been one of research hotspots in the field of porous materials. However, the reported porous materials containing fullerene are very limited. Herein, porous fullerene-bearing polycarbazole FulCPOP with permanent porosity was synthesized from carbazole-bearing fullerene derivative via carbazole-based oxidative coupling polymerization. Considering that fullerene possesses high chemical reactivity to complex with transition metals in η2-fashion, post-polymerization functionalization of FulCPOP by coordination with palladium and rhodium complexes made porous fullerene-bearing polymer to form metal complex hybrid composites FulCPOP-Pd and FulCPOP-Rh, respectively. Their gas (H2, CO2, CH4) uptake capacities and catalytic performance as heterogeneous hydrogenation catalysts were explored. FulCPOP-Rh not only exhibited a better catalytic activity with a higher conversion (64–77%) than FulCPOP-Pd (29–38%), but also had a higher selectivity. Moreover, compared with catalytic activities of fullerene metal complex molecules, porous hybrid composite FulCPOP-Rh showed a better catalytic performance in a shorter reaction time and a lower H2 pressure. Fullerene-bearing porous polymers and their metal complex hybrid composites may allow for gas uptake, hydrogenation and other applications.