Two-dimensional NiAl layered double oxides as non-noble metal catalysts for enhanced CO methanation performance at low temperature

Abstract

The development of non-noble nickel-based catalysts for CO methanation reaction at low temperature still constitutes a challenge. This paper describes the synthesis of two-dimensional NiAl layered double oxides (NiAl-LDO) by flash-nanoprecipitation (FNP) method and their evaluation as low temperature CO methanation catalysts. The expanded NiAl-LDO catalyst with a stoichiometric Ni:Al ratio of 3:1(E-NiAl-LDO3.0) exhibits specific surface area of 252.1 m2/g, a pore volume of 0.45 cm3/g and an average pore diameter of 7.3 nm, which render it highly active for CO methanation at relatively low temperature. Thus, E-NiAl-LDO3.0 affords excellent CO conversion of 100% and CH4 selectivity of 90.6% at 200 °C. Even at 120 °C, CO conversion of 88.0% and CH4 selectivity of 85.0% are achieved. After 60 h, the E-NiAl-LDO3.0 still shows100% activity retention much better than 92% at 400 °C. This work demonstrates that high Ni-content and delamination improves the catalyst performance in the CO methanation reaction at low temperature.