An Al2O3-supported NiFe bimetallic catalyst derived from hydrotalcite precursors for efficient CO2 methanation

Abstract

The unsatisfactory low-temperature activity of Ni based catalysts in CO2 methanation calls for further optimization of catalyst design. In the present work, an efficient Ni7Fe1/Al2O3 bimetallic catalyst was derived from hydrotalcite precursors that were grown in-situ on the commercial γ-Al2O3. The resultant Ni7Fe1/Al2O3 bimetallic catalyst exhibited exceptional low-temperature activity, whose CO2 conversion reached 75.3% at 270 ºC under atmospheric pressure. Moreover, the Ni7Fe1/Al2O3 catalyst remained stable at 350 ºC for 50 h. Structural characterizations revealed that the exceptional activity over the bimetallic catalyst was closely related with the formation of NiFe alloy, which modified the electronic property, enhanced the metal reducibility and enriched the surface basic sites of Ni catalysts. The good stability on the bimetallic catalyst was mainly ascribed to the excellent coke- and sintering- resistance. This work develops an efficient methanation catalyst and clarifies the effect of bimetallic synergism in CO2 methanation.