La-enhanced Ni nanoparticles highly dispersed on SiC for low-temperature CO methanation performance

Abstract

For better performances of Ni-based catalysts at low temperatures, Ni/SiC catalyst doped with a little amount of additive La was successfully prepared. The catalytic CO methanation activity tests showed that 3%La–Ni/SiC catalyst was excellent at a low reaction temperature (95.9% CO conversion and 85.1% CH4 selectivity at 250 °C) with a superior stability compared with Ni/SiC (3.4% CO conversion and 0% CH4 selectivity at 250 °C). This can be attributed to that the addition of La can markedly improve the dispersibility of active metal Ni and reduce the particle sizes of Ni nanoparticles or clusters, and can also regulate the interaction between active components and supports. Moreover, the high thermal conductivity and thermal stability could avoid the generation of hot spots in the catalyst bed. These results will promote the development of highly active Ni-based catalysts for the low-temperature methanation reaction.