A Study on Thermally Stable Transition Metal Complexes Loaded Hierarchically Porous Carbon for Catalysis and Mechanism

Abstract

Metal complexes with high thermal stability were incorporated in hierarchically porous carbon support using the co-gelation technique. Hierarchically porous carbon was formed by using resorcinol and formaldehyde as a precursor of a polymer with a surfactant F127 for mesoporous structure and diaminohexane for a macroporous structure. The metal complexes incorporated were copper (II) protoporphyrin IX (CuIX), copper phthalocyanine disulfonate (CuPc2S), and Alcian Blue (CuPc-8gx). These compounds being paramagnetic are electron paramagnetic resonance (EPR) active hence, their stabilities after pyrolysis were monitored by (EPR) technique. The CuIX loaded on carbon when heated to 380°C showed the signal of copper and there was a very little signal of copper after it was heated to 500 °C. The CuPc2S and CuPc-8gx, both dyes loaded on carbon were heated to 500 °C and found to be stable with the EPR results. CuPc2S, however, showed large blobs of copper agglomerate all over the surface, unlike the other two compounds. The discrepancy in this behavior of CuPc2S was further investigated by a fluorescence quenching experiment.