A DFT Study On The Process Of Partial Oxidation Of Methane

In recent years, the research for Partial Oxidation of Methane to syngas is a highlight in C1 chemistry. A series of key processes in POM are calculated and discussed by computer molecular simulation technique in this paper. In order to improve the precision of calculation, a periodic surface including thirteen Ni atoms is built, which can effectively eliminate the influence of boundary effect. As addition, by means of embedding method, the reactants are imported, and the adsorption sites and space structure are calculated by geometry optimization.This paper systematically studies the adsorptions and dissociations of CHx(x=0~4) on Ni(1 1 1)surface for the first time; calculates the adsorption sites, space structures and adsorption energies of CHx(x=0~4) on Ni(1 1 1)surface; finds the dissociation routes and translation states of CHx(x=0~4) using LST/QST method; obtains the activation energies and dissociation energies for every step. Meanwhile, Mulliken Population Analysis is carried out to confirm the results.The reaction routes and activation energies of two possible paths of CO generation are discussed. According to the theory of transition state, this paper brings forward that the main principle of CO generation is:The results of experiments support the conclusion by molecular simulation. The GC analysis for product shows that methane dissociates on spongy Ni catalyst in multi-step. The ESEM of catalyst show that the Ni surface is covered by the species of CH4 dissociation without oxygen existing in a short time.On the basis of quantum chemistry, a periodical molecular model is constructed and the processes of the adsorption and dissociation of methane on Ni(1 1 1)surface are systematically investigated in this paper. Furthermore, this paper discusses and perfects the generation mechanism of the product of POM, which is supported by fundamental experiments. The work in this paper will supply guidance in theory for future research.