Effect of thermal induction temperature on re-dispersion behavior of Ni nanoparticles over Ni/SBA-15 for dry reforming of methane

Abstract

In the previous research, we found that thermal treatment at high temperature could induce the re-dispersion of Ni particles on SBA-15 for dry reforming of methane (DRM). Here, we aimed to study the re-dispersion behavior of Ni particles of Ni/SBA-15 at different temperatures. The results indicated that the mean Ni particle size of Ni/SBA-15 catalysts were 16.9 nm, 14.5 nm, 7.1 nm and 18.4 nm after thermal treatment at 700 °C, 800 °C, 900 °C and 1000 °C, respectively. It could be seen the optimal inducing temperature of Ni/SBA-15 was at 900 °C. The relatively lower inducing temperature did not drive the re-dispersion of Ni particles sufficiently, while the large Ni particles were formed by re-aggregation of re-dispersive Ni species at relatively higher inducing temperature. After 34 h DRM reaction, encapsulated carbon was formed over the catalyst induced by low temperature and the catalytic performance decreased. However, a slight amorphous carbon was discovered over the catalyst induced at 900 °C with highly dispersion. Interestingly, in spite of a large amount of carbon deposition, the 1000Ni/SBA-15 still maintained excellent catalytic activity.