Methane oxidation by green oxidant to methanol over zeolite-based catalysts

To reduce greenhouse gas emission from oil and gas production, it is essential to better convert methane to useful chemicals (rather) than to flare it. Conversion of methane to liquid oxygenates (mainly methanol) has attracted extensive attention and countless efforts have been made; however, running this reaction in a green, efficient, and practical way has remained elusive. The novel catalyst and oxidants play a critical role in activating methane and converting it to oxygenates (methanol). In this review, the work of commonly used oxidants for methane partial oxidation have been summarized, in which, earth abundant oxidants, O2 and H2O are promising. Moreover, H2 or CO can activate O2 to produce H2O2 that catalyzes methane partial oxidation more efficiently and selectively than O2 or H2O. Therefore, the work of using reducing agent, such as CO and H2 have been reviewed, focusing on rational catalyst design that features multifunction (H2O2 production and CH4 activation). The novel catalyst design has advanced this reaction towards practicality with green oxidants and H2 using zeolites-based catalyst. Environmentally friendly zeolite preparation methods and novel two-dimensional (2D) zeolites that can reduce waste, improve synthesis and catalytical performance substantially are also reviewed in this work to provide insights for a more comprehensive approach to meet the environment protection needs.