Facile preparation of Cu–Mn/CeO2/SBA-15 catalysts using ceria as an auxiliary for advanced oxidation processes

Abstract

A facile synthetic method was adopted to prepare heterogeneous catalysts using ordered mesoporous silica SBA-15 as matrix, ceria as auxiliary and Cu–Mn as the catalytic active sites, denoted as Cu–Mn/CeO₂/SBA-15. Characterization results demonstrate that the metal oxide nanoparticles are well-dispersed inside the mesopores rather than aggregated outside the surface. The particle sizes range from 4.1 to 11.2 nm with an increase in calcination temperature from 300 to 500 °C. The presence of ceria plays a significant role in the formation of well-dispersed metal oxide nanoparticles, and a possible mechanism for the preparation of this heterogeneous catalyst is proposed based on comparable experimental results. Catalytic degradation studies for advanced oxidation processes (AOPs) show that Cu–Mn/CeO₂/SBA-15 catalysts can efficiently degrade (>99%) high-concentration dye pollutants (C = 2 g L⁻¹) within 210 min at 70 °C and can retain a good degradation efficiency even at a pH value of 7 when using Rhodamine B as the model pollutant. The excellent AOP catalytic performance could be ascribed to the well-dispersed catalytic nanoparticles inside the mesopores and the catalytic synergic effect of CeO₂. Our work here displays a simple method to synthesize heterogeneous catalyst with well-dispersed nano-sized catalytic active sites for AOPs by using CeO₂ as the auxiliary agent.