Dynamic Frustrated Lewis Pairs on Ceria for Direct Nonoxidative Coupling of Methane

Huang, Zheng-Qing1; Zhang, Tianyu4; Chang, Chun-Ran1; Li, Jun2,3,5

2019-06

10.1021/acscatal.9b00838

ACS Catalysis   影响因子和分区

2155-5435

While the regulation of surface oxygen vacancy (V-O) of ceria is an effective methodology to construct solid frustrated Lewis pairs (FLPs), the intrinsic properties and potential applications of solid FLPs are not well-demonstrated. Herein, we present a theoretical study on the formation rules and dynamic behaviors of FLPs on CeO2(110) and their performance on nonoxidative conversion of methane. The density functional theory studies show that the formation of solid FLPs on CeO2(110) is dependent on the number of oxygen vacancies (V(O)s). The FLPs constructed by three or more V(O)s are stable in thermodynamics, whereas the FLPs containing few V(O)s (i.e., V-O monomer and V-O dimer) are less stable but can be dynamically formed via thermal fluctuation and reactant-adsorption, as observed by ab initio molecular dynamics simulations. Hence, the general existence of FLPs on reduced CeO2(110) surface under reaction conditions is revealed. Calculations on methane activation show that FLPs are active for C-H bond breaking with an activation energy as low as 0.63 eV, attributed to the enhanced acidity and basicity of FLPs. Because of the structure of FLPs, the subsequent dissociation of a second methane and the C-C coupling of CH3 to form C2H6 is relatively prevailing at FLP sites, different from the popular gas-phase coupling mechanism. Ethane can be further dehydrogenated at FLP sites to form more valuable ethylene. On the basis of these findings, our study provides insights into the formation and dynamic behaviors of solid FLPs on CeO2 and more importantly predicts a promising strategy for nonoxidative coupling of methane into more valuable chemicals on abundant oxide-based catalysts.

dynamic frustrated Lewis pairs CeO2 methane C-H activation oxygen vacancy

SCI ; EI

英语

其他

Fundamental Research Funds for the Central Universities[xtr0218016] ; Fundamental Research Funds for the Central Universities[cxtd2017004]

Chemistry

Chemistry, Physical

WOS:000471212600081

AMER CHEMICAL SOC

20192407032151

Reaction kinetics ; Surface reactions ; Activation analysis ; Cerium oxide ; Ethylene ; Activation energy ; Dimers ; Oxygen vacancies ; Calculations ; Density functional theory ; Thermodynamics ; Molecular dynamics

Thermodynamics:641.1 ; Physical Chemistry:801.4 ; Chemical Reactions:802.2 ; Organic Compounds:804.1 ; Inorganic Compounds:804.2 ; Organic Polymers:815.1.1 ; Mathematics:921 ; Probability Theory:922.1 ; Atomic and Molecular Physics:931.3 ; Quantum Theory; Quantum Mechanics:931.4 ; Crystalline Solids:933.1

Web of Science

1.Xi An Jiao Tong Univ, Sch Chem Engn & Technol, Shaanxi Key Lab Energy Chem Proc Intensificat, Xian 710049, Shaanxi, Peoples R China
2.Tsinghua Univ, Dept Chem, Beijing 100084, Peoples R China
3.Tsinghua Univ, Key Lab Organ Optoelect & Mol Engn, Minist Educ, Beijing 100084, Peoples R China
4.Southern Illinois Univ, Dept Chem & Biochem, Carbondale, IL 62901 USA
5.Southern Univ Sci & Technol, Dept Chem, Shenzhen 518055, Peoples R China

Huang, Zheng-Qing,Zhang, Tianyu,Chang, Chun-Ran,et al. Dynamic Frustrated Lewis Pairs on Ceria for Direct Nonoxidative Coupling of Methane[J]. ACS Catalysis,2019,9(6):5523-5536.

Huang, Zheng-Qing,Zhang, Tianyu,Chang, Chun-Ran,&Li, Jun.(2019).Dynamic Frustrated Lewis Pairs on Ceria for Direct Nonoxidative Coupling of Methane.ACS Catalysis,9(6),5523-5536.

Huang, Zheng-Qing,et al."Dynamic Frustrated Lewis Pairs on Ceria for Direct Nonoxidative Coupling of Methane".ACS Catalysis 9.6(2019):5523-5536.