Metal-organic Framework As A Precursor For Synthesis Of Inverse CeO₂/CuO Catalysts For Preferential Oxidation Of CO

We used heterobimetallic metal-organic framework as precursors to prepare CeO2/CuO catalysts for preferential oxidation of CO. It demonstrated that the heterobimetallic MOF precursors might prevent the aggregation of CeO2and CuO during the formation of catalysts and the calcining conditions through decomposition of MOFs precursors affected significantly with the catalytic activity. With the increasing of the calcination temperature, organic matter decomposed gradually and the CuO and CeO2phase grow sufficiently dispersed in the first instance, while a further increase resulted in a lower surface content of Cu and the agglomeration. With the decreasing of the calcination rate, the more amount of highly dispersion copper oxide existed.A series of Co3O4-CeO2supports with different Co/Ce ratio have been synthesized by using polyethyleneglycol (PEG) as a surfactant. The catalytic performance tests indicated the activity of the catalysts is better than the corresponding support. In addition, CuO/(0.7)Co3O4-CeO2displayed the best activity with100%CO conversion and93%O2selectivity at120℃. Furthermore, the stability test of CuO/(0.7)Co3O4-CeO2expressed the activity can be retained at80%for80h at100℃. Catalysts and supports were characterized by BET, XRD, TPR and TPD techniques. Discussion of the results showed that the strongest lattice distortion and the best reducibility of Co3O4-CeO2supports were both negative factors for the catalytic activity. More precisely, an appropriate Co/Ce ratio can restrain the stronger interaction between cobalt oxide and ceria to promote the formation of reducible copper species.