Designing hydrotalcite-derived CoAlO catalysts for highly selective catalytic CO2 methanation

Designing non-noble metal catalysts with simultaneous high activity and selectivity for CO2 methanation has been a challenge. Here, we report a highly efficient layered CoAlO catalyst, fabricated by facile direct reduction of hydrotalcite-like precursors, for efficient catalytic CO2 methanation to produce methane at low temperature and atmospheric pressure. It displayed outstanding space-time yield (STY) of 0.46 gCH4⋅gcat−1⋅h−1, which was about 3 times than that of supported catalysts under the given conditions, and good stability within 200-h durability test. The characterization results revealed that the designed CoAlO catalyst had appropriate alkaline and reducibility, which could significantly enhance adsorption and activation of CO2. Meanwhile, the formation mechanism of active Co species was clearly revealed by monitoring the phase change of catalyst during the reduction process, and the structure-activity relationship of the catalysts were clarified in detail. This work offers a promising catalytic design for efficient catalytic CO2 methanation.