Biomass as a renewable carbon resource, it is of great significance to convert it into high value-added chemicals such as polyols, aromatics, alkanes, etc. Nickel-based catalysts in the hydrogenation, hydrocracking and hydrodeoxygenation of biomass It has been shown to have high catalytic activity. However, in the reaction medium for biomass conversion (strong acid, high temperature, hydrothermal), most of the nickel-based catalysts are not stable, mainly due to the low-valent nickel-based catalytically active species. In the acid solution, it is easy to cause dissolution, loss and aggregation growth, which leads to the loss of activity of the catalyst. This disadvantage has also become a huge obstacle to limit the application of nickel-based catalysts in biomass conversion reactions. Therefore, there is an urgent need to develop a new type of acid resistance. Stable nickel-based catalyst and used in the field of biomass hydrogenation.
Recently, Wang Aiqin, a researcher at the Center for Aerospace Catalysis and New Materials of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, and the team of academicians Zhang Tao, who have been engaged in the research of single-atom catalysts and biomass conversion for the first time, will be the first to carry high-metal-loaded nickel-nitrogen-carbon (Ni-NC). Monoatomic catalysts have been used in biomass conversion reactions and have made important progress. Related work was published in the form of communication on "Angew. Chem. Int. Ed." and was selected as a hot paper.
The research team prepared a Ni-NC monoatomic catalyst with a nickel loading of up to 7.5 wt% and applied it to cellulose conversion to prepare polyol reactions. Comparison of activated carbon-supported nickel nanoparticle catalysts (Ni/AC), Ni-NC single atom The catalyst shows good durability under the harsh conditions of high temperature, high pressure, strong acid, high temperature and hydrothermal conditions. The catalyst can be circulated more than 7 times and no obvious decrease in activity and single atom aggregation grow up. Through in-depth characterization, the researchers It was successfully analyzed that the active center of the Ni-NC single-atom catalyst is a nickel-mono atom coordinated with four pyridine nitrogens to form a twisted quasi-planar Ni-N4 group, while the fifth pyridine nitrogen is weakly adsorbed in the longitudinal direction. The nickel center forms the Ni-N5 structure, and hydrogen molecules can be effectively activated on the active center. This progress is for the conversion of biomass into cosmetics (polyols), polyester fibers (diols/diacids/PX), aviation High value-added chemicals such as kerosene (aromatic hydrocarbons) have important implications.
The above research work has been funded by the National Natural Science Foundation of China, the Ministry of Science and Technology, the Strategic Leading Science and Technology Project of the Chinese Academy of Sciences and the Collaborative Innovation Center for Energy Materials Chemistry of the Ministry of Education.
