Chromium and cobalt bimetallic MOF material as an effective and stable catalyst for the decomposition of cyclohexyl hydrogen peroxide

Abstract

The decomposition of cyclohexyl hydrogen peroxide (CHHP) is a crucial step in the preparation process of cyclohexanone by non-catalytic oxidation of cyclohexane in industry. In this study, the chromium-cobalt bimetallic MOF material MIL-101(Cr, Co) was first successfully prepared by hydrothermal synthesis. Its structure was characterized by various means, and it was applied to CHHP decomposition to estimate the stability of the material. The results showed that Cr3+ and Co2+ were successfully coordinated with carboxyl groups of terephthalic acid by Cr–O and Co–O bond, respectively, MIL-101(Cr, Co) has excellent performance as a catalyst in the CHHP decomposition reaction, and the introduction of Co2+ as a metal node makes MIL-101(Cr, Co) have a high specific surface area, as well as improves the conversion rate of CHHP to 91.6%, which was clearly higher than MIL-101(Cr) (70.3%). The most important thing is that the framework structure of the MIL-101(Cr, Co) is stable during the six recycling runs, and the loss amount of chromium and cobalt in the reaction solution during reuse is less than 1 ppm.