Green technology for carbon dioxide utilization: Vermiculite based hydrotalcite for methane dry reforming

In this paper, the abundant metal ions in the vermiculite-modified waste stream were utilized to prepare vermiculite-based hydrotalcite precursors, and hydrotalcite-like bimetallic catalysts were synthesized by the co-precipitation method and used in the methane dry reforming reaction. The experimental results showed that the Ni-Co/VMT-LDO catalyst showed good activity with 84% CH4 conversion and 87% CO2 conversion at 750 °C and 18000 mL/(g·h). The catalyst was characterized by XRD, SEM, BET, H2-TPR, TEM and TG. TEM tests before and after the reaction showed that the addition of Co decreased the average particle size of Ni. Meanwhile, thermogravimetric tests of the spent catalysts revealed that the weight loss of the bimetallic catalysts was significantly smaller than that of the monometallic catalysts, in which the Ni-Co/VMT-LDO showed better anti-carbon accumulation performance than the other two catalysts. This study not only solves the environmental problems caused by vermiculite modification, but also enhances the economic utilization of vermiculite. Vermiculite-based hydrotalcite-loaded bimetallic catalysts have been shown to be effective catalysts for dry reforming of methane.