Preparation of Co/Ce Bimetallic Foam-Based Catalyst for Catalytic Oxidation of Toluene

Abstract

Bimetallic synergism can effectively improve the catalytic activity of the catalyst. In this work, different catalysts were synthesized by loading Co and Ce onto copper foam (CF) by impregnation method and applied to the catalytic oxidation of toluene. Catalytic performance of the Co/Ce loaded catalysts was significantly better than the CF. Among these catalysts, Co₁Ce₂/CF catalyst had the best catalytic activity of toluene (T₉₀ = 237 °C), the lowest apparent activation energy (Ea = 35.0 kJ/mol), excellent stability (40 h) and cycle stability (three cycle) at a toluene concentration of 1000 mg/m³ under WHSV = 15,000 mL/(g·h). The good catalytic activity of Co₁Ce₂/CF catalyst is mainly due to a higher proportion of lattice oxygen, Ce⁴⁺ and Co²⁺. Ce⁴⁺ and Co²⁺ can provide more oxygen vacancies for the catalyst. By H₂-TPR and O₂-TPD, it is found that Co₁Ce₂/CF catalyst's effective catalytic activity is probably attributed to its low reduction temperature, ample oxygen storage capacity and low oxygen desorption temperature. In addition, the degradation process of toluene on the catalyst was speculated. The physical and chemical properties of the catalysts were investigated by SEM, EDS, XRD, XPS, BET, H₂-TPR and O₂-TPD. This work provides an effective way for synthesizing Co-Ce bimetallic oxide supported catalysts with great potential in toluene treatment.

Graphical Abstract