Enhancing the low-temperature CO2 methanation over Ni/La-CeO2 catalyst: the effects of surface oxygen vacancy and basic site on the catalytic performance

TY - JOUR

T1 - Enhancing the low-temperature CO2 methanation over Ni/La-CeO2 catalyst: the effects of surface oxygen vacancy and basic site on the catalytic performance

AU - Zhang, Tengfei

AU - Wang, Weiwei

AU - Gu, Fangna

AU - Xu, Wenqing

AU - Zhang, Jianling

AU - Li, Zhenxing

AU - Zhu, Tingyu

AU - Xu, Guangwen

AU - Zhong, Ziyi

AU - Su, Fabing

PY - 2022/4/8

Y1 - 2022/4/8

N2 - This work reports a strategy to promote the low-temperature CO2 methanation on the Ni-based catalyst by tuning the surface oxygen vacancy and medium-strength basic sites of the CeO2 support and thus changing the reaction pathway. La species was introduced into CeO2 support and calcined at 600 °C (CeO2-La-600) to form a La-Ce-O solid solution with a thin La2O2CO3 layer on the surface, generating more basic sites and oxygen vacancies. This unique structure facilitated the adsorption and direct dissociation of CO2. Over Ni/CeO2-La-600, the reaction follows the HCOO* and *CO pathways, while over Ni/CeO2-600, the reaction occurs via the HCOO* pathway only. The decomposition of CO2* to *CO is energetically more favorable than hydrogenation to HCOO* on Ni/CeO2-La-600, resulting in its higher catalytic performance at low temperatures. This work unravels the complex interplay among oxygen vacancy, basic site, and reaction pathway in CO2 methanation over the Ni-based catalysts.

AB - This work reports a strategy to promote the low-temperature CO2 methanation on the Ni-based catalyst by tuning the surface oxygen vacancy and medium-strength basic sites of the CeO2 support and thus changing the reaction pathway. La species was introduced into CeO2 support and calcined at 600 °C (CeO2-La-600) to form a La-Ce-O solid solution with a thin La2O2CO3 layer on the surface, generating more basic sites and oxygen vacancies. This unique structure facilitated the adsorption and direct dissociation of CO2. Over Ni/CeO2-La-600, the reaction follows the HCOO* and *CO pathways, while over Ni/CeO2-600, the reaction occurs via the HCOO* pathway only. The decomposition of CO2* to *CO is energetically more favorable than hydrogenation to HCOO* on Ni/CeO2-La-600, resulting in its higher catalytic performance at low temperatures. This work unravels the complex interplay among oxygen vacancy, basic site, and reaction pathway in CO2 methanation over the Ni-based catalysts.

KW - CO2 methanation

KW - Ni catalyst

KW - La-Ce-O solid solution

KW - Performance

KW - Mechanism

U2 - 10.1016/j.apcatb.2022.121385

DO - 10.1016/j.apcatb.2022.121385

M3 - 文章

SN - 0926-3373

JO - Applied Catalysis B: Environmental

JF - Applied Catalysis B: Environmental

ER -