Enhanced CO oxidation with cobalt-impregnated porous single-crystal manganese oxides

Abstract

Porous single crystals (PSCs) have the advantages of both long-range ordered lattice structure and disordered connected pore structure, which can provide structural coherence and long-distance electronic connectivity, thus reducing the energy loss at grain boundaries and maintaining high stability and activity. In our work, we prepared PSCs Mn₂O₃, Mn₃O₄ and MnO and loaded cobalt on these PSCs by impregnation to test the catalytic performance of CO oxidation. The results show that all PSC manganese oxides loaded with cobalt can maintain good performance and cobalt-loaded PSC MnO can completely oxidize CO at 170 °C. In the case of fully adsorbed 1% CO, the proportion of oxygen species adsorbed on the surface becomes the key factor determining the reaction performance. Among them, Mn₂O₃ loaded with cobalt can maintain long-term stability for 127 h without attenuation. Furthermore, all cobalt-loaded manganese oxides can complete 30 catalytic cycles. This work provides an idea for the design of PSCs and gives a reference for the study of CO oxidation in the field of non-noble metals.