Highly active and stable Ni/γ-Al₂O₃ catalysts selectively deposited with CeO₂ for CO methanation

TY - JOUR

T1 - Highly active and stable Ni/γ-Al2O3 catalysts selectively deposited with CeO2 for CO methanation

AU - Liu, Qing

AU - Gao, Jiajian

AU - Zhang, Meiju

AU - Li, Huifang

AU - Gu, Fangna

AU - Xu, Guangwen

AU - Zhong, Ziyi

AU - Su, Fabing

PY - 2014

Y1 - 2014

N2 - We report the preparation of highly active, coking- and sintering-resistant CeO2-decorated Ni/γ-Al2O3 catalysts by an impregnation method followed by a modified deposition-precipitation (DP) of CeO2. The samples were characterized by nitrogen adsorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, H2 temperature-programmed reduction, H2 temperature-programmed desorption and zeta potential analysis. The results revealed that compared with the Ni catalysts with a NiO loading of 40 wt% prepared by co-impregnation (CI) and sequential impregnation (SI) methods, the Ni catalyst synthesized by DP method showed enhanced catalytic performance for CO methanation at atmospheric pressure and an extremely high weight hourly space velocity (WHSV) of 240000 mL g-1 h-1. In a 50 h high-pressure life-test, this catalyst showed a high resistance to both coking and sintering. It was found that CeO2 nanoparticles were selectively deposited on the surface of NiO rather than on Al2O3 due to the electrostatic interaction during the DP process, effectively preventing Ni particles from sintering during the reduction and reaction at high temperatures, and inhibiting coke formation by increasing the supply of active oxygen species on the nickel surface. As a result, the formed CeO 2-decorated Ni/Al2O3 catalyst exhibited excellent catalytic performance and stability in CO methanation. This work demonstrated that catalytic properties could be much improved for a usual catalyst with a well-designed structure. This journal is

AB - We report the preparation of highly active, coking- and sintering-resistant CeO2-decorated Ni/γ-Al2O3 catalysts by an impregnation method followed by a modified deposition-precipitation (DP) of CeO2. The samples were characterized by nitrogen adsorption, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, thermogravimetric analysis, H2 temperature-programmed reduction, H2 temperature-programmed desorption and zeta potential analysis. The results revealed that compared with the Ni catalysts with a NiO loading of 40 wt% prepared by co-impregnation (CI) and sequential impregnation (SI) methods, the Ni catalyst synthesized by DP method showed enhanced catalytic performance for CO methanation at atmospheric pressure and an extremely high weight hourly space velocity (WHSV) of 240000 mL g-1 h-1. In a 50 h high-pressure life-test, this catalyst showed a high resistance to both coking and sintering. It was found that CeO2 nanoparticles were selectively deposited on the surface of NiO rather than on Al2O3 due to the electrostatic interaction during the DP process, effectively preventing Ni particles from sintering during the reduction and reaction at high temperatures, and inhibiting coke formation by increasing the supply of active oxygen species on the nickel surface. As a result, the formed CeO 2-decorated Ni/Al2O3 catalyst exhibited excellent catalytic performance and stability in CO methanation. This work demonstrated that catalytic properties could be much improved for a usual catalyst with a well-designed structure. This journal is

UR - http://www.scopus.com/inward/record.url?scp=84898061940&partnerID=8YFLogxK

U2 - 10.1039/c4ra00746h

DO - 10.1039/c4ra00746h

M3 - 文章

AN - SCOPUS:84898061940

SN - 2046-2069

VL - 4

SP - 16094

EP - 16103

JO - RSC Advances

JF - RSC Advances

IS - 31

ER -