a: calculated from N2adsorption-desorption data b: calculated from Hg intrusion data
c: d(Co) = 0.75 d(Co3O4) d: D (%) = 96/d(Co)
All catalysts presented similar reduction behavior according to the reduction profiles of the catalysts studied by H2-TPR, as seen in Figure 1S(c) (see Supporting Information). The reduction peaks at 200°C-300°C, 250°C-500°C, 550°C-900°C were usually contributed to the reduction of Co3O4 to CoO, CoO to metallic Co31,32,37 and the reduction of amorphous Co/silica phase, individually, Co/S50 and Co/S150 had relatively larger area of the second reduction peak which was mainly caused by the larger crystallites size of these two catalysts. Besides, the quite weak reduction peaks (at 250°C-500°C) of all catalysts indicated a good reducibility and a weak interaction between active phase and supports.
4.2 Reaction performance assessment over hierarchical catalyst
After 24 h of reaction with the steady state achieved, the performances of the prepared FTS catalysts are collected as in Table 3S (see Supporting Information) and Figure 3. The large catalyst pellets (10-20 mesh) of FTS, commonly recognized to bear severe internal diffusion limitations, were employed to investigate the mass transfer enhancement with the meso-macropore structure.