The Effect of Different Promoters (La(2)O(3), CeO(2), and ZrO(2)) on the Catalytic Activity of the Modified Vermiculite-Based Bimetallic NiCu/EXVTM-SiO(2) Catalyst in Methane Dry Reforming

[Image: see text] An X-NiCu/EXVTM-SiO(2) (X = La, Ce, and Zr) catalyst was successfully prepared by using modified vermiculite as a support by the impregnation method. This experiment investigated the effects of La(2)O(3), CeO(2), and ZrO(2) promoters on the activity of the NiCu/EXVTM-SiO(2) catalyst. The study found that the addition of three different metal oxides did not improve the activity of the NiCu/EXVTM-SiO(2) catalyst. On the contrary, some Ni active sites were covered by the promoter, which reduced the number of active sites, resulting in its catalytic activity lower than NiCu/EXVTM-SiO(2). In addition, the promoted catalysts that were repeatedly calcined two times can significantly reduce the textural property as well as active sites of the catalyst, resulting in the lower activity. However, in X-NiCu/EXVTM-SiO(2), Ce-NiCu/EXVTM-SiO(2) showed relatively high initial catalytic activity, with the initial conversion rate of CH(4) reaching 60.1% and the initial conversion rate of CO(2) reaching 89.1%. This is mainly because the catalyst has a stronger basic site on the surface to facilitate the adsorption of CO(2) molecules, and the smaller metal particle size is also conducive to the cleavage of C–H bonds.