Recently, the research team of Deng Dehui from the Research Group of the Special Zone for Innovation of Two dimensional Materials and Energy Small Molecule Transformation (05T6 Group) of the State Key Laboratory of Catalysis Foundation of our institute has cooperated with the team of Professor Wang Ye from Xiamen University, and made important progress in the research of carbon dioxide (CO2) catalytic hydrogenation to methanol. For the first time, a few layers of molybdenum disulfide (MoS2) catalyst rich in sulfur vacancies has been used to realize low-temperature, efficient and long-life CO2 hydrogenation to methanol. Its activity and selectivity are significantly better than commercial Cu/ZnO/Al2O3 catalysts, and show excellent stability. This catalyst has opened up new avenues for achieving low energy consumption and high efficiency in CO2 conversion and utilization.
The efficient conversion and utilization of CO2 has important strategic significance for alleviating energy crisis and achieving the goal of carbon neutrality. The use of renewable energy based green hydrogen (H2) to react with CO2 to produce methanol is an important approach. Traditional metal oxide catalysts typically require high reaction temperatures (>300oC) to catalyze CO2 hydrogenation to methanol, often accompanied by severe reverse water gas shift (RWGS) reactions, resulting in the production of a large amount of byproduct carbon monoxide (CO). Introducing transition metal components into metal oxide catalysts can promote the activation of H2 and lower the reaction temperature, but at the same time, it can easily lead to excessive hydrogenation of CO2 to methane (CH4), thereby reducing the selectivity of methanol. The mutual constraint between activity and selectivity in the metal/metal oxide catalytic CO2 hydrogenation to methanol system severely limits the improvement of its low-temperature catalytic performance. Therefore, in order to achieve low-temperature and efficient hydrogenation of CO2 to methanol, it is urgent to seek new catalyst systems.




The Deng Dehui team has long been committed to the research of two-dimensional catalytic materials and energy small molecule conversion, and has made a series of progress in regulating the catalytic activity of two-dimensional MoS2 in the early stage (Nat. Commun., 2020; Angew. Chem. Int. Ed., 2020; Nano Energy, 2020; Nano Energy, 2019; Chem. Rev., 2019; Nat. Commun., 2017; Energy Environment. Sci., 2015). On this basis, the team collaborated with Wang Ye's team to study and found that the few layer MoS2 rich in sulfur vacancies can directly activate and dissociate CO2 and H2 simultaneously at low temperatures or even room temperature, thereby catalyzing the low-temperature hydrogenation of CO2 to methanol with high activity and selectivity, and effectively suppressing the excessive hydrogenation of methanol. At 180oC, the catalyst can achieve a single pass conversion rate of 12.5% for CO2 and a methanol selectivity of 94.3%, which is significantly better than the commercial Cu/ZnO/Al2O3 catalyst and previously reported catalysts. In addition, the activity and selectivity of the catalyst can be stably maintained for 3000 hours at 180oC without any decay, demonstrating excellent industrial application potential. The results of in-situ characterization and theoretical calculations show that the in-plane sulfur vacancies in MoS2 are the active centers for catalyzing the highly selective hydrogenation of CO2 to methanol. This work reveals the potential application of sulfur vacancies in two-dimensional MoS2 in catalytic reactions, providing new ideas for the development of novel catalysts for CO2 hydrogenation.
The relevant research results were published on March 22 in Nature Catalysis. In addition, Nature Catalysis also published an expert review article titled "Catalysis by Unusual Vacancies" during the same period, which highly praised the work. The above work has been supported by the Key Research and Development Program of the Ministry of Science and Technology of China, the Basic Science Center and Major Projects of the National Natural Science Foundation of China, the B-class leading special project "Precision Construction Principles and Measurement of Functional Nanosystems" of the Chinese Academy of Sciences, and the Collaborative Innovation Center for Energy Materials Chemistry of the Ministry of Education (2011 · iChEM).