Explore the "black box" of catalysis
——Remember the first prize of the National Natural Science Award "Nano Confined Catalysis" project team
Our reporter's common sense
In modern industry, the production of most products is closely related to the catalytic process.
However, due to the complexity of the catalysis process, it is difficult to clearly understand the mechanism of catalysis, and it has always been regarded as a "black box".
A few days ago, the team led by Bao Xinhe, an academician of the Chinese Academy of Sciences and a researcher at the Dalian Institute of Chemical Physics of the Chinese Academy of Sciences, provided innovative theoretical support for revealing the "black box" and won the first prize of the National Natural Science Award.
After the reform and opening up, my country's economic strength and scientific and technological strength have gradually improved, and the demand for high-level talents in various fields has become more urgent.
Bao Xinhe is full of fighting spirit in the new year.
my country is an oil-poor, gas-less, and coal-rich country. Relying heavily on imported oil to produce liquid fuels and chemicals is related to national energy security.
For the national strategic needs, he aimed at the efficient and clean conversion of non-petroleum resources such as coal and natural gas, and focused his research on the conversion of small energy molecules to produce liquid fuels and essential chemicals, determined to decrypt the "black box" of catalysis.
In 2006, Bao Xinhe's team found that during the process of filling the iron oxide nanoparticles into carbon nanotubes, the carbon nanotubes not only limited the size of the nanoparticles, but also the reduction temperature of the iron oxide in the tube decreased with the diameter of the tube. While the reduction is lower than that of the nanoparticles directly attached to the outside of the tube, there is a big difference in the activity of the nanoparticles inside and outside the carbon nanotube.
After careful experimental design and a lot of research, the team found that the curling caused the electron cloud originally symmetrically distributed on both sides of the carbon nanotube to shift from the inside of the tube to the outside of the tube, distorting the electronic structure of the originally inert carbon layer. The formation of a potential difference promotes the reduction of nanoparticles in the tube, thereby forming a coordinated unsaturated metal active center.
The unique nano-scale luminal structure of carbon nanotubes and its electronic confinement environment cause changes in the properties of the materials in the tubes, and even induce new properties of the materials in the tubes.
Based on this, Bao Xinhe team put forward the narrow concept of "restricted catalysis".
Later, the concept was extended to a two-dimensional and interface interaction electronic control system, that is, the concept of "interfacial confinement catalysis", which together constitute the narrow and general confinement in the concept of "nano confinement catalysis". Aspects.
"Accurate control of chemical reaction processes has always been the goal pursued by catalytic chemistry. Driven by today's demand for efficient energy conversion, resource optimization and optimization of the ecological environment, the catalytic process needs to be gentler, and the catalytic reaction more precise and efficient." Bao Xinhe said.
With the formation and improvement of the concept of nano confinement catalysis, Bao Xinhe's team created the OXZEO catalytic system by coupling the interface confinement and the pore confinement, which realized the direct production of ethylene, propylene and butene from coal through synthesis gas in one step with high selectivity. In principle, low-carbon olefins abandon the traditional Fischer-Tropsch (FT) synthesis route, eliminate the water-consuming and energy-consuming water-gas shift and water-hydrogen cycle process, and successfully break through the theoretical limit of the target product selectivity.
"Innovation is a long process. It needs to be built on long-term accumulation and a solid foundation. Without a lot of early work as a foreshadowing, a breakthrough cannot be achieved." Fu Qiang, a researcher at the Dalian Institute of Physics, told reporters.
"Innovations in the chemistry field often go through the chemical process to enter the application field. As a scientist, you must discover, invent, and create something." said Duan Xue, an academician of the Chinese Academy of Sciences and professor of the Department of Applied Chemistry at Beijing University of Chemical Technology.
Bao Xinhe team naturally hopes that this achievement can be applied industrially to serve the national chemical industry.
Based on this innovative achievement, Dalian Institute of Chemical Technology and Shaanxi Yanchang Petroleum (Group) Co., Ltd. cooperated to build the world's first 1,000-ton-scale industrial test device for direct production of low-carbon olefins from coal via synthesis gas.
The single-reactor commissioning will be completed in 2019, and the entire industrial process test will be successfully completed in 2020, further verifying the advancement and feasibility of the technical route.
"Theory guides practice. In the future, based on the concept of nano-restricted catalysis, there will be more technologies to achieve industrial application, which will improve the efficiency of resource utilization in my country and the world." Bao Xinhe said.