Preparation of highly dispersed supported Ni-Based catalysts and their catalytic performance in low temperature for CO methanation

The use of non-noble nickel-based catalysts for low temperature CO methanation has been a challenge in recent years. Herein, MgAl layered double oxides sample with high dispersion synthesized by a facile N-(2-Hydroxyethyl) ethylenediaminetriacetic acid assisted wetness impregnation approach, demonstrates much superior catalytic activity and exceptional stability for CO methanation in comparison with the classical Ni/MgAl-LDO catalyst prepared by the ordinary wetness impregnation method. HRTEM results showed that N-(2-Hydroxyethyl)ethylenediaminetriacetic acid played a positive role in the dispersion of Ni, as well as Ni-support interaction. Well-dispersed Ni particles with a size of about 5 nm were formed in the presence of N-(2-Hydroxyethyl) ethylenediaminetriacetic acid. Compared to the Ni/MgAl-LDO prepared by conventional impregnation method, the NH-Ni/MgAl-LDO exhibited superior catalytic performance, especially excellent thermal stability. The NH-Ni30/MgAl-LDO catalyst was found to keep a 70 % CO conversion even at 160 °C which demonstrates its good low temperature performance. From the in situ FTIR observations, this good performance at low temperatures may be linked to the delocalization of electrons around CO caused by surface hydroxyl groups.