Using innovative copper-loaded activated alumina (Cu/AA) as the catalyst for catalytic wet peroxidation (CWPO) of catechol

Abstract

Abstract As a low-cost technology, the catalytic wet-peroxidation (CWPO) process can be operated without lamps and at atmospheric temperature and pressure. Currently, many studies focus on developing new catalysts for CWPO to increase the catalysts’ stability and efficiency. In this study, copper-loaded activated alumina (Cu/AA) was synthesized and used for the CWPO of catechol (a representative refractory organic pollutant). Various characterization techniques were deployed to characterize the catalysts, e.g., activated alumina (AA), as well as pristine and spent 1% Cu/AA. The innovative 1% Cu/AA catalyst exhibited good thermal stability up to 1173 K with a marginal weight loss of 13%. The Cu species were well dispersed on the activated alumina framework with no significant cluster formation. Typically, copper particles with a diameter of 20.74 nm were dispersed on the AA framework. Catechol removal was observed to be 92% with 87% mineralization at optimized conditions (initial catechol concentration = 200 mg/L, catalyst dose of 1% Cu/AA = 1 g; temperature = 323 K; pH = 6; and H2O2/catechol stoichiometric ratio = 0.5). The mineralization of catechol was analyzed using mass spectroscopy with the associated mechanism being elucidated. Results of this study indicate the synthesized catalyst has phenomenal advantages in terms of simple separation and high removal efficiency of catechol, indicating the feasibility of using Cu/AA as the catalyst for the CWPO of catechol.