Catalytic Combustion of Toluene over Highly Dispersed Cu-CeOx Derived from Cu-Ce-MOF by EDTA Grafting Method

Abstract

In this work, Cu-CeOx-MOF catalysts with well-dispersed Cu in different contents were synthesized via the ethylenediaminetetraacetic acid (EDTA) grafting method. EDTA was grafted in Ce-MOF-808 to anchor Cu and then the metal-organic frameworks (MOFs) were utilized as sacrificial template to form highly performed Cu-CeOx-MOF for toluene catalytic combustion. In this series of samples, Cu-CeOx-MOF-0.2 had a higher ratio of Oα/(Oα+Oβ), more oxygen vacancies and performed better low-temperature reducibility. Cu-CeOx-MOF-0.2 showed outstanding catalytic activity and stability. The T90 (temperature when toluene conversion achieved 90%) of Cu-CeOx-MOF-0.2 was 226 °C at 60,000 mL/(gcat∙h). In situ diffuse reflectance infrared transform spectroscopy (in situ DRIFTS) results revealed that the opening of aromatic ring and the deep oxidation of carboxylate were key steps for toluene catalytic combustion over Cu-CeOx-MOF-0.2.