Co and Ni single sites on the(111)n surface ofγ-Al2O3–a periodic boundary DFT study  

作　　者：Jiande Gu Jing Wang Jerzy Leszczynski 

机构地区：[1]Interdisciplinary Nanotoxicity Center,Department of Chemistry,Physics and Atmospheric Sciences,Jackson State University,Jackson,MS 39217,USA

出　　处：《Industrial Chemistry & Materials》2023年第1期117-128,共12页工业化学与材料（英文）

基　　金：supported by the NSF PREM grant#1826886;The computer time was provided by the Extreme Science and Engineering Discovery Environment(XSEDE)by the National Science Foundation Grant Number OCI-1053575;XSEDE award allocation number DMR110088 and by the Mississippi Center for Supercomputer Research.

摘　　要：The influences of increasing the number of d-electrons in the single metal(Fe-like)substituted(111)n surface ofγ-Al2O3 on its possible catalytic effects were explored.The energetic properties,local structures,and in-site electron configurations of the most active tri-coordinated Co and Ni single-site(111)n surface ofγ-Al2O3 have been studied using the density functional theory(DFT)approach under periodic boundary conditions.The replacement of Al by a Co or Ni atom on the I position of the(111)n surface leads to significant elongations of metal–O distances.The energy released from the substitution process on the AlI site of the(111)n surface follows the sequence NiI(164.85 kcal mol−1)>CoI(113.17 kcal mol−1)>FeI(44.30 kcal mol−1).The triplet and quintet(ground state)of the CoI substituted complex are energy degenerate.Also,the doublet and quartet(ground state)of the NiI substituted complex have the same stable energy.This energy degeneracy comes from theα–βelectron flipping on the p-orbital of the neighboring O that is next to the substituted CoI or NiI site on the(111)n surface ofγ-Al2O3.Different from the FeI substituted single-site(111)n surface,in which the electron configuration of FeI varies according to its spin-multiplicity state,substituted NiI has a unique d8 electron configuration in all three spin states,and similarly,CoI has a unique d7 electron configuration in all three open shell spin states.An increase of the population of d-electrons in the single metal substituted(111)n surface ofγ-Al2O3 is likely to provide a more stable electron configuration in the metal catalytic center.

关 键 词：Co substituted surface ofγ-Al2O3 Ni substituted surface ofγ-Al2O3 (111)n surface Periodic boundary DFT approach Metal catalytic center 

分 类 号：O62[理学—有机化学]