Debromination of 1,2,4,5-Tetrabrominated Benzene in Alcohol Solution with Nanoscale Pd/C Particles: Factors, Pathways, and Mechanism

Abstract

In this study, the catalytic debromination of 1,2,4,5-tetrabrominated benzene (1245TBB) was performed in a solution of NaOH in alcohol (Visopropanol:Vmethanol = 99:1) in the presence of a nanoscale catalyst Pd/C at a temperature of 50°C. The final degradation product of 1,2,4,5-tetrabrominated benzene is benzene. The debromination efficiency of 1245TBB and its degraded intermediate products (1,2,4-tribromobenzene, 1,2,-dibromobenzene, and bromobenzene) were highly dependent on the Pd/C loading and NaOH concentration. The catalyst life was evaluated, which showed that the deactivated catalyst could be reactivated about 30% after washing with 100 mmol L-1 NaOH solution in isopropanol. The possible 1245TBB debromination mechanism and pathways are also proposed and discussed in this study.