Research Progress of Catalysts for Catalytic Methane Combustion

Abstract

As the main component of natural gas, methane (CH4) is the second most prominent greenhouse gas after carbon dioxide (CO2). The control of methane emissions is crucial for mitigating global warming. Due to the stable structure of methane, traditional combustion-based elimination technologies require high temperatures above 1000°C, resulting in considerable energy consumption and the generation of other polluting gases. Therefore, catalytic methane combustion (CMC) technologies have been developed, offering advantages such as low pollution, high efficiency, and stability. These systems can achieve the low-temperature combustion of methane at low concentrations with the aid of catalysts. The core challenge in developing this technology is the construction of high-performance catalysts, which are required to possess high activity, high stability, and an excellent anti-poisoning ability. However, due to the high C-H bond energy of methane, developing low-temperature and highly efficient catalysts is extremely difficult. For CMC, catalysts such as noble metals (Pd-based and Pt-based e.g.) and non-noble metals (single-metal oxides, composite metal-oxides, and perovskite-type, spinel-type, hexaaluminate-type, and pyrochlore-type oxides) have been widely studied and applied. This review briefly introduces the properties of methane and the elimination methods currently in use, comprehensively considers the factors influencing the performance of various catalysts and the mechanisms by which CMC can be achieved. Finally, the limitations of existing catalysts are summarized, and potential improvement strategies are considered, including the development of future new catalysts and novel approaches for further exploring the reaction mechanisms.