燃料化学学报2020，Vol.48Issue(6)：704-712,9.
第一性原理研究镍改性ZSM-12分子筛的酸性
Acid properties of Ni-modified ZSM-12: A first-principles study
摘要
Abstract
The catalytic performance of zeolites in industry can often be enhanced by modification with transition metals and Ni is one of the most widely used transition metals for the hydrogenation and dehydrogenation catalysts. In this work, the structure and acid properties of Ni-modified HAl-ZSM-12 zeolites were investigated by the dispersion corrected periodic density functional theory. The results indicate that single Ni atoms can reduce the H atoms in the zeolites into H2 molecule, whereas the Ni clusters like Ni2 cannot . The quantity of Br?nsted acid sites may decrease after the modification with single Ni atoms;the Ni atoms in the zeolites are oxidized and work as strong Lewis acid sites, which may weaken the Lewis acidity of Al3+. After modification with Ni, the Ni-modified ZSM-12 displays greater ability to adsorb hydrogen molecules. The adsorbed hydrogen molecules are dissociated to negatively charged H atoms, which do not function as Br?nsted acid sites. Due to the transfer of electron from the Ni atoms to the pre-adsorbed H atoms, as revealed by the adsorption energy of NH3 , the pre-adsorption of hydrogen on the Ni-modified ZSM-12 zeolites can enhance the Lewis acidity.关键词
Ni/ZSM-12分子筛/酸性/密度泛函理论/吸附能/氢Key words
Ni/ZSM-12 zeolite/acidity/density functional theory/adsorption energy/hydrogen分类
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冯刚,肖祈,王大山,周健,卢章辉,张荣斌..第一性原理研究镍改性ZSM-12分子筛的酸性[J].燃料化学学报,2020,48(6):704-712,9.基金项目
The project was supported by the National Natural Science Foundation of China (21875096, 21763018, 21673270), and the Natural Science Foundation of Jiangxi Province (20181BAB203016, 20181BCD40004). （21875096, 21763018, 21673270）
