*2.3. N2 Adsorption and Desorption Curves*

Figure 3 and Table 2 show the N2 physical adsorption curves and the physical properties of the investigated catalysts. Seen from the Figure 3, the curves are typical type II isotherms accompanying with a H3 type hysteresis loop, which indicates that mesoporous exits in the catalysts. The presence of mesoporous can also be seen from the pore size distribution curves.

**Figure 3.** (**a**) The N2 physical adsorption curves and (**b**) Barrett–Joyner–Halenda (BJH) pore size distribution of catalysts.

**Table 2.** The physical properties of all the investigated catalysts.


<sup>a</sup> Calculated from X-ray diffraction results with the Scherrer equation. <sup>b</sup> The reduced catalysts. <sup>c</sup> The catalysts after reaction. <sup>d</sup> The 200 h stability test. <sup>e</sup> The degree of dispersion. <sup>f</sup> The crystal size calculated by hydrogen temperature-programmed desorption (H2-TPD).

For LKCG-x (x = 0.1 and 0.2) catalysts, with the addition of K, the hysteresis loop increases and moves to lower P/P0, illustrating the investigated catalysts have bigger BET surface area. The larger surface area results in the higher dispersion of metal cobalt nanoparticles (see in Table 2).
