Scientists put forward a new strategy of methane conversion

Shanghai Silicate Research Institute of the Chinese Academy of Sciences announced on February 24 that the research team led by researcher Wang Wenzhong of the Institute has made new progress in the research of photocatalytic conversion of methane and proposed a new strategy for direct conversion of methane to liquid fuel under mild conditions. The direct conversion of photocatalysis can break the shackles of traditional thermodynamic equilibrium and make the conversion of methane under low temperature and atmospheric pressure. Wang Wenzhong's research team designed and prepared copper modified carbon nitride materials to realize the direct photocatalytic conversion of methane to ethanol, and conducted a more in-depth study on the mechanism of this process.

In view of the problem that methane is prone to over activation and thorough mineralization, the research team not only realized the formation of hydroxyl radicals, but also promoted the activation of methane C-H bond and the stability of highly active intermediate species through copper modification in the orderly cavity of carbon nitride materials from the two perspectives of the generation of active oxygen species and the adsorption and activation of methane. The material shows excellent photocatalytic performance for methane conversion. The copper species in the material has synergistic effect with adjacent carbon atoms, which makes the conversion process along the path of methane methanol ethanol. As the main component of natural gas, shale gas, etc., methane has the advantages of relatively rich reserves and low price. It is one of the core research and development in academia and industry in the field of alternative oil production of liquid fuel and basic chemicals.

The selective activation and directed conversion of methane is a worldwide problem, which is known as the "Holy Grail" in the field of catalysis and even chemistry. So far, the indirect method is usually used in the conversion of methane, which is converted into syngas by steam reforming at high temperature, and then multi carbon basic chemicals are obtained by Fischer Tropsch synthesis, or methanol is prepared from syngas and other chemicals are produced. The energy consumption of the conversion route is high, and a large amount of greenhouse gas carbon dioxide is emitted in the process, which not only brings environmental load, but also makes the utilization rate of total carbon less than half. Therefore, scientists have been trying to explore the method of direct conversion and utilization of methane.