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Synthesis of a Highly Active and Stable Nickel‐Embedded Alumina Catalyst for Methane Dry Reforming: On the Confinement Effects of Alumina Shells for Nickel Nanoparticles
Author(s) -
Huang Qiong,
Fang Xiuzhong,
Cheng Qinzhen,
Li Qian,
Xu Xianglan,
Xu Luoji,
Liu Wenming,
Gao Zhixian,
Zhou Wufeng,
Wang Xiang
Publication year - 2017
Publication title -
chemcatchem
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.497
H-Index - 106
eISSN - 1867-3899
pISSN - 1867-3880
DOI - 10.1002/cctc.201700490
Subject(s) - carbon dioxide reforming , catalysis , nickel , materials science , chemical engineering , nanoparticle , mesoporous material , coke , syngas , nanotechnology , metallurgy , chemistry , organic chemistry , engineering
A 12 % Ni@Al 2 O 3 catalyst was synthesized by using an inverse microemulsion technique and evaluated for the dry reforming of methane (DRM). We used TEM to reveal that the core–shell structure was formed successfully in the 12 % Ni@Al 2 O 3 catalyst, in which the Ni nanoparticle cores with an average grain size around 10 nm are encapsulated by mesoporous Al 2 O 3 shells. In comparison with a 12 % Ni/Al 2 O 3 catalyst prepared by an impregnation method, much smaller Ni grain sizes and higher metallic Ni active surface areas can be achieved in the core–shell catalyst, which was evidenced by using TEM and H 2 adsorption–desorption analysis. In addition, a larger amount of active oxygen species was formed on the surface of 12 % Ni@Al 2 O 3 than on 12 % Ni/Al 2 O 3 . Importantly, the formation of the core–shell structure in 12 % Ni@Al 2 O 3 can effectively impede the migration of the Ni active species at elevated temperatures, which prevents agglomeration. Consequently, the 12 % Ni@Al 2 O 3 core–shell catalyst shows a remarkable activity and stability and a potent coke resistance during a 50 h durability evaluation at 800 °C for DRM. It is believed that the core–shell structure is the major factor that accounts for the superior DRM performance over that of the 12 % Ni@Al 2 O 3 catalyst, which might open a new way for the design and development of improved catalysts for DRM for hydrogen production.