材料科学
镍
催化作用
烯烃纤维
X射线吸收光谱法
纳米颗粒
选择性
X射线光电子能谱
化学工程
金属
吸附
吸收光谱法
无机化学
光化学
冶金
纳米技术
物理化学
有机化学
化学
物理
工程类
量子力学
作者
Yuanshen Wang,Yufei Zhao,Jinjia Liu,Zhenhua Li,Geoffrey I. N. Waterhouse,Run Shi,Xiaodong Wen,Tierui Zhang
标识
DOI:10.1002/aenm.201902860
摘要
Abstract Ni‐based catalysts are traditionally considered unsuitable for the Fischer–Tropsch syntheses of olefins, due to the very strong hydrogenation ability of metallic Ni. Herein, this paradigm is challenged. A series of MnO supports nickel catalysts (denoted herein as Ni‐ x ) are fabricated by H 2 reduction of a nickel‐manganese mixed metal oxide at temperatures ( x ) ranging from 250 to 600 °C. The Ni‐500 catalyst displays unprecedented performance for photothermal CO hydrogenation to olefins, with an olefin selectivity of 33.0% under ultraviolet–visible irradiation. High‐resolution transmission electron microscopy, X‐ray absorption spectroscopy (XAS), and X‐ray diffraction analyses reveal that the Ni‐ x catalysts contain metallic Ni nanoparticles supported by MnO. X‐ray photoelectron spectroscopy and XAS establish that electron transfer from MnO to the Ni 0 nanoparticles is responsible for modifying the electronic structure of nickel (creating Ni δ− states), thereby shifting the CO hydrogenation selectivity toward light olefins. Further, density functional theory calculations show that this electron transfer lowers the adsorption energies of olefins on Ni surfaces, thus minimizing the undesirable deep hydrogenation reactions to higher alkanes. This study conclusively demonstrates that MnO‐modified Ni‐based catalyst systems can be highly selective for CO hydrogenation to light olefins.
科研通智能强力驱动
Strongly Powered by AbleSci AI