“…As for CoMnZn/SiO 2 , the reduction peak at 265 °C was assigned to the partial reduction of Co 2 ZnO 4 and Co 2 MnO 4 composite oxides, and the latter peak at about 420 °C was further reduced to metallic Co (Co δ+ to Co 0 ). 14,18,55 Compared with CoMnZn/SiO 2 , the reduction temperature corresponded to the second reduction step for CoMnZn/Al 2 O 3 , increasing from 420 to 480 °C, while the first peak shifted from 265 to 250 °C. However, for TiO 2 -supported catalysts, both reduction peaks shifted toward a lower temperature, where the first peak shifted to 240 °C and the second peak shifted to 390 °C (CoMnZn/r-TiO 2 ), 400 °C (CoMnZn/P25), and 415 °C (CoMnZn/a-TiO 2 ), respectively.…”