Ni@SiO2核壳型催化剂上孔调控对甲烷干重整催化性能的影响OA北大核心CSTPCD

Ni@SiO2 core-shell catalysts were prepared by oil-in-water microemulsion method.Adding a gradient amount of substance of cetyltrimethylammonium bromide(C16TAB)for post-treatments,Ni@SiO2-x C16 catalysts with distinct porous structures were prepared.By characterization techniques including N2 adsorption/desorption,XRD,TEM,H2-TPR,XPS and Raman spectroscopy,the catalysts were analyzed,and the effects of pore structures on Ni@SiO2-x C16 shell on the activity,stability and anti-coking performance of catalysts were investigated.The results indicate that Ni@SiO2-x C16 has a larger specific surface area and more abundant pore structures,which help to improve the dispersion of Ni particles,limit the size of Ni particles to less than 5 nm and strengthen the interaction between Ni particles and supports.In a 50 h stability test,Ni@SiO2 has a low initial CH4 conversion rate(68.5%)and weak stability,but after C16TAB post-treatment,Ni@SiO2-2C16 and Ni@SiO2-3C16 show high initial CH4 conversion rates(both about 84.1%)and high stability,and n(H2)/n(CO)in products exceeds 0.97 and almost no deactivation occurred.After further study,it is found that the type of carbon species in Ni@SiO2-xC16 changes from a large amount of graphite carbon that is difficult to eliminate to a small amount of disordered carbon that is easy to remove.Therefore,the performances of anti-coking and anti-sintering of Ni@SiO2-xC16 are improved.