Issue 6, 2022 - Research on selective oxidation of methane has progressed

Recently, researchers from the Institute of Precision Measurement Science and Technology Innovation of the Chinese Academy of Sciences and Cardiff University in the United Kingdom have made important progress
in the study of selective oxidation of methane.
The research team developed a gold(Au)-supported ZSM-5 zeolite (Au/ZSM-5) catalyst, which realized the catalytic reaction process of catalyzing the highly selective oxidation of methane to methanol and acetic acid under oxygen conditions, and conducted in-depth research
on its catalytic mechanism.

As the cleanest and most abundant natural carbon resource, methane is distributed in natural gas, shale gas, coalbed methane, methane hydrate, etc.
, and can be used as an important_C1 resource
for the production of high-value chemicals.
Due to the remoteness of methane storage, the conversion of methane into transportable oxygenated compounds (methanol, formic acid, acetic acid, etc.
) at the mining site is of great significance
for the efficient use of methane.

However, due to the large C-H bond energy of methane, it usually requires harsh conditions (high temperature and high pressure) to convert it, such as the energy-intensive indirect conversion process in industry that first converts methane into syngas and then into a high value-added product
.
There has been a long quest to partially oxidize methane directly into high value-added chemicals, and due to the more reactive nature of the oxygenated compounds they produce, they are often more prone to over-oxidation to by-products
such as carbon dioxide.
Therefore, selective oxidation of methane is called one of
the "holy grail" reactions in catalysis.
The search for a selective oxidation route for methane capable of industrial promise under mild conditions has attracted great attention
from academia and industry.

In response to the above problems, the researchers developed an Au/ZSM-5 catalyst with nanoparticles Au as the oxidation center
.
The catalyst can achieve selective oxidation of methane to methanol and acetic acid
under the condition of 120 °C ~ 240 °C under the condition of no co-reducing agent (hydrogen or carbon monoxide).
This work not only provides experimental evidence for heterogeneous catalysts to achieve selective oxidation of methane under oxygen conditions, but also provides new research ideas
for the "holy grail" reaction in the catalytic field of methane selective conversion.