Scientists achieve low temperature and high efficiency CO2 catalytic hydrogenation to methanol
 

The greenhouse gas carbon dioxide (CO2) is the end product of many chemical reactions. Its excessive emissions aggravate the rise of global average temperature and bring great pressure to the ecological environment. How to efficiently transform and utilize CO2 and turn it into treasure is a hot and difficult research topic in the field of energy and chemical industry.

Deng Dehui, a researcher at the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and Wang Ye, a professor at Xiamen University, have recently made important progress in the study of catalytic hydrogenation of CO2 to methanol. For the first time in nearly 6 years, the research team achieved low temperature, high efficiency and long life catalytic HYDROGENation of CO2 to methanol by using low-layer molybdenum disulfide (MoS2) catalyst rich in sulfur vacancies. The activity and selectivity of MoS2 catalyst were significantly better than those of metal oxide catalysts previously reported, and showed excellent stability, which opened up a new way to achieve low energy consumption and high efficiency of CO2 conversion and utilization. The study is in the journal Nature Catalysis.

The preparation of methanol by reaction with green hydrogen (H2) based on renewable energy is one of the important ways to turn CO2 waste into treasure. In general, the reaction temperature of traditional metal oxide catalysts is more than 300 degrees Celsius, and a serious reverse water gas conversion reaction is often accompanied, resulting in the production of a large number of by-products carbon monoxide. The introduction of transition metal components in the metal oxide catalyst can promote the activation of H2 and reduce the reaction temperature, but it is easy to lead to the excessive hydrogenation of CO2 to produce methane, which reduces the selectivity of the target product methanol. It is urgent to seek a new catalyst system for methanol production from LOW temperature hydrogenation of CO2.

In previous studies, Dundehui’s team found that mos2-based catalysts performed well in catalytic electrolysis of water to produce H2. Conversely, “can MoS2 activate H2 at room temperature and efficiently catalyze CO2 hydrogenation to methanol?” With this idea, Deng and Wang Ye will launch a joint team. However, at the beginning, the research progress was not smooth, the catalytic performance of MoS2 did not achieve the expected effect, and the traditional way of introducing other elements into MoS2 to adjust the catalyst performance also failed to significantly improve the catalyst performance.

After reaching an impasse, the team switched to making MoS2 react with H2, creating a large number of sulfur vacancies on the surface, and then activating the stable MoS2 surface. By modulating the structure of MoS2 itself, researchers developed a low-layer MoS2 with rich sulfur vacancies. The MoS2 catalyst can directly activate and dissociate CO2 and H2 at low temperature or even room temperature, and effectively inhibit the excessive hydrogenation of methanol. The results of in-situ characterization and theoretical calculation show that the in-plane sulfur vacancy of MoS2 is the active center for highly selective hydrogenation of CO2 to methanol.

It is worth mentioning that in the laboratory test, the one-way conversion rate of CO2 at 180 degrees Celsius can reach 12.5%, and the selectivity of methanol is as high as 94.3%, which is significantly better than the previously reported metal and metal oxides and other traditional catalysts, and the performance can be maintained for 3000 hours without decay, showing excellent industrial application potential.

The journal Nature Catalysis published a review article titled “Unusual vacancy Catalysis” at the same time, praising the research. Professor Felix Studt of the Karlsruhe Institute of Technology (KIT) said: “This is an amazing and interesting work, which is expected to bring huge efficiency gains for industrial applications in the hydrogenation of carbon dioxide to methanol.”

Deng dehui said that efficient conversion and utilization of CO2 is an important link to achieve “carbon peak” and “carbon neutrality”. This study revealed the application potential of sulfur vacancy of TWO-DIMENSIONAL MoS2 in catalytic reaction, and provided a new idea for the development of new catalysts for CO2 hydrogenation. It is hoped that more enterprises can participate in and jointly promote the industrial application of MoS2 catalyzed CO2 hydrogenation to methanol


Post time: Feb-22-2022