Methane Activation and Utilization: Current Status and Future Challenges

Methane, an abundant and clean fossil energy source, can provide the highest specific energy compared with other hydrocarbons. Exploiting an efficient way to convert methane to fuel or chemicals is, therefore, of significant importance economically as well as in terms of sustainability. Generally, methane is first converted to syngas in industry, which is further transformed to liquid hydrocarbons via a Fischer-Tropsch process. Methane is also directly pyrolyzed to olefins or aromatic hydrocarbons or coupled to C-2 products at very high temperatures. Among all the direct routes, the selective oxidation of methane to methanol is noteworthy as it is thermodynamically favorable under relatively mild reaction conditions. However, restricted by the high C-H bond energy, the activation and utilization of methane still encounters great challenges despite the developments in recent years. Based on this background, this Review highlights the recent advances and forthcoming challenges in the process of methane activation and utilization. Catalysis plays a key role in the process of methane activation and it is focused on here. This Review is expected to be useful for scientists and engineers working in this field and is timely to boost further research.