文献类型：期刊文献

英文题名：High syngas selectivity and near pure hydrogen production in perovskite oxygen carriers for chemical looping steam methane reforming

作者：Zhao, Kun[1,2,3];Zhang, Rongjiang[4];Gao, Yunfei[5];Lin, Yan[1,2,3];Liu, Anqi[1,2,3];Wang, Xiaobo[1,2,3];Zheng, Anqing[1,2,3];Huang, Zhen[1,2,3];Zhao, Zengli[1,2,3]

机构：[1]Chinese Acad Sci, Guangzhou Inst Energy Convers, Guangzhou 510640, Peoples R China;[2]CAS Key Lab Renewable Energy, Guangzhou 510640, Peoples R China;[3]Guangdong Prov Key Lab New & Renewable Energy Res, Guangzhou 510640, Peoples R China;[4]Xi An Jiao Tong Univ, Sch Chem Engn & Technol, Shanxi Key Lab Energy Chem Proc Intensifcat, Xian 710049, Shaanxi, Peoples R China;[5]East China Univ Sci & Technol, Shanghai Engn Res Ctr Coal Gasificat, Key Lab Coal Gasificat & Energy Chem Engn, Minist Educ, Shanghai 200237, Peoples R China

年份：2022

卷号：236

外文期刊名：FUEL PROCESSING TECHNOLOGY

收录：;EI(收录号：20223112525303);WOS:【SCI-EXPANDED(收录号:WOS:000835233800002)】；

基金：The authors gratefully acknowledge the National Natural Science Foundation of China (51876205 and 51776209, 22179027) , the Youth Innovation Promotion Association, CAS (2019341) and the Science and Technology Program of Guangzhou (201904010128) for their financial support of this work.

语种：英文

外文关键词：Chemical looping; Methane reforming; Hydrogen; Oxygen vacancy

摘要：Chemical looping steam methane reforming (CL-SMR) provides an attractive route for hydrogen and syngas co-production through two successive steps of methane oxidation and steam splitting. However, there is also carbon formation through CH4 cracking which hampers the production of syngas (H-2 and CO) and the following pro-duction of pure H-2. This work prepared the perovskites La(0.95)Ce(0.05)NixFe(1-x)O(3) (x = 0, 0.2, 0.5, 0.8, 1.0) as oxygen carriers for CL-SMR. The methane activation and steam splitting were investigated based on reactivity tests on a fixed-bed reactor and various characterizations. Results showed that La0.95Ce0.05Ni0.2Fe0.8O3 and La0.95Ce0.05-Ni0.5Fe0.5O3 reached a high syngas selectivity (94.8%, 89.0%) accompanied with good methane conversion (93.1% and 95.7%) for methane partial oxidation, and near 100% hydrogen concentrations (higher than 99.6% and 99.5%) for steam splitting, indicating that additional separation step for pure hydrogen acquisition can be omitted. The H-2/CO molar ratio was maintained at the optimal value of 2.0 throughout the methane partial oxidation process. Characterizations and density functional theory calculations demonstrated that methane partial oxidation was promoted via an oxygen vacancy-mediated Mars-van-Krevelen type mechanism and the partial oxidation ability of the oxygen carrier is restricted by its content of oxygen vacancy and lattice oxygen migration rate. The proper amount of Ni doping forming the Ni-Fe synergetic effects also contributed highly to methane partial oxidation. Afterward, the deeply reduced metals combined with the oxygen vacancies provided active sites for steam splitting, hence generating pure H-2.