Methane activation on nickel oxide clusters with a concerted mechanism: a density functional theory study of the effect of silica support

• Published in: Journal of molecular modeling 2016-04, Vol.22 (4), p.79-79, Article 79
• Main Authors: Xi, Yanyan, Chen, Bili, Lin, Xufeng, Wang, Chuangye, Fu, Hui
• Format: Article
• Language: English
• Subjects: Characterization and Evaluation of Materials; Chemistry; Chemistry and Materials Science; Computer Appl. in Life Sciences; Computer Applications in Chemistry; Molecular Medicine; Original Paper; Theoretical and Computational Chemistry
• ISSN: 1610-2940; 0948-5023
• DOI: 10.1007/s00894-016-2947-7

The support effect is an important issue in heterogeneous catalysis. A systematic density functional theory (DFT) study was performed to investigate the support effect of a silica model on the initial step of methane activation on Ni x O x (x =2,3) clusters with a concerted mechanism. Four reactions were examined by exploring their potential energy surfaces (PES): CH 4 reacting with unsupported Ni 2 O 2 , with silica-supported Ni 2 O 2 , with unsupported Ni 3 O 3 , and with silica-supported Ni 3 O 3 . For each reaction, PES with different spin states were explored. For CH 4 activation taking place via a concerted mechanism, the reaction barriers in terms of free energy and reaction free energy increased with the involvement of the model silica support. Only one PES made a major contribution to the overall reaction rate of all four reactions examined. No spin transition process was required for the reactions to undergo their most-favorable pathway from their starting reactants. These results provide a deeper insight into the support effect on C–H bond activation of small alkanes in general, and of methane in particular, on supported transition metal catalysts. Graphical Abstract Different reaction behaviors of CH 4 on nickel oxide clusters at the absence and presence of silica support