Thermocatalytic Behavior of TiO 2 as a Dehydrogenation Catalyst: A Case Study of Methane Activation and Nonoxidative Coupling

Year: 2026

Type: article

Abstract: High Resolution Image Download MS PowerPoint Slide The abundance of cheap natural gas has changed the energy supply landscape and spurred efforts to find alternative sources of energy to traditional fossil fuels. Methane (CH 4 ) is the primary constituent of natural gas, and its C–H bond activation remains a long-standing puzzle in the chemical industry. Transition-metal oxides exhibit intrinsic Lewis acid–base properties beneficial for activating the C–H bonds of CH 4 . In this work, we investigated the nonoxidative coupling of CH 4 (NOCM) to C 2 hydrocarbons on the rutile TiO 2 (110) surface at 1240 K by using density functional theory (DFT) calculations. We explored three different CC coupling pathways for the formation of ethane after the sequential activation of two CH 4 molecules. We found that CH 3 /CH 3 coupling involves high activation barriers, while the formation of C 2 H 5 from the coupling of CH 3 /CH 2 is kinetically and thermodynamically more facile. Considering ethylene formation routes, we found that the dehydrogenation of methyl species requires high energy barriers. However, the subsequent CC coupling of CH 2 /CH 2 occurs at a lower activation barrier of 1.01 eV. Moreover, our calculations revealed that the dehydrogenation of C 2 H 5 to form ethylene is favored over its hydrogenation to form ethane. This work provides various mechanistic pathways that can help in designing dehydrogenation catalysts with enhanced catalytic activity. However, our results indicate that despite low barrier coupling routes, rutile TiO 2 alone is not an effective catalyst for NOCM due to the energy-intensive C–H activation and limited stability of reactive intermediates. Rutile TiO 2 may have enhanced activity and selectivity in doped configurations or as a catalyst support within multifunctional catalytic systems.

Source: ACS Omega

DOI: 10.1021/acsomega.5c10988

Authors: Juganta K. Roy, Mona Abdelgaid, Giannis Mpourmpakis

Institutions: University of Pittsburgh, West Texas A&M University, National Technical University of Athens

Language: English

Topic: Catalysis and Oxidation Reactions

Subfield: Catalysis

Field: Chemical Engineering

Domain: Physical Sciences

SDGs: Climate action, Affordable and clean energy

Open Access status: gold

Estimated APC paid: $1,935

Funders: National Science Foundation, University of California Berkeley, University of Pittsburgh, San Diego Supercomputer Center, American Chemical Society Petroleum Research Fund, Center for Research Computing, University of Pittsburgh, Office of Advanced Cyberinfrastructure

OpenAlex ID: W7124930913