One of the greatest modern inventions of mankind is plastic, which plays an important role in our life. Plastic bags, plastic bottles and plastic lunch boxes greatly facilitate our lives, but they also bring us huge environmental problems. More than 75% of disposable plastics can not be recycled after use. They will enter the sea, sewers and other places, harm wildlife and pollute our environment.

　　Now, at least 4.9 billion tons of plastic waste in the world is buried underground or in nature. With the growth of plastics market, 380 million tons of plastics are produced every year in the world, and the output is still growing. If we don't take further measures, nature will be flooded with plastic. However, these problems are very difficult to deal with.

　　The life of plastics is very long. It takes 10 to 20 years for a plastic bag to degrade and 500 years for a plastic bottle to degrade. Even if it seems to "disappear", its remains still exist. Over time, the plastic will slowly break down into smaller pieces and eventually become very tiny plastic particles. Every year, 10 million tons of plastics flow into the ocean, but only 1% of them float on the sea, and the rest become micro plastics, which may be swallowed by marine organisms.

　　The good news is that humans are now aware of the seriousness of the problem. For the existing plastic problems, scientists are studying how to transform them. Nature catalyst has published a paper on polymer decomposition, which directly turns a variety of plastic wastes into hydrogen. The work was carried out by researchers such as Peter Edwards of Oxford University, Tiancun Xiao and John Thomas of Cambridge University, who used microwave activated iron-based catalyst particles to effectively degrade crushed plastic waste and extract hydrogen. The whole process takes only one step and takes only 30-90 seconds to convert a variety of real-life plastic waste into clean fuel hydrogen, with a yield of 55.6   mmol / g plastic. In addition, the solid residue after the degradation of plastic waste is mainly multi walled carbon nanotubes, which also has high application value.

　　Turning plastic into hydrogen has made a great contribution to solving plastic pollution, and now it can turn plastic into diesel! You can kill two birds with one stone.

　　Recently, researchers such as fr é D é ric a. perras, Aaron D. Sadow and Wenyu Huang of Iowa State University published a paper in nature catalysis. Inspired by the fact that proteases in nature digest proteins by repeatedly cutting molecular chains, they designed a catalytic "scissors" (msio2 / Pt / SiO2) based on mesoporous silica and platinum nanoparticles, High density polyethylene (HDPE), a common plastic, can be cut into small molecular alkane fragments, and the products can be used for the preparation of diesel oil and lubricating oil.

　　The overall structure of the new catalyst is "mesoporous shell / active site / core". The active site of platinum nanoparticles is located at the bottom of mesoporous silica shell (above). The long chain of HDPE can easily move in the pores, but the subsequent escape is inhibited by the polymer surface interaction. This is similar to the binding and transport of protein substrate in the cleavage of protease catalysis. In this way, the platinum nanoparticles at the bottom of the mesoporous can catalyze the hydrogenolysis of long polyethylene chains to produce alkanes with narrow and adjustable chain length distribution. By adjusting the pore size of the catalyst, the chain hydrocarbon mixtures with C14, C16 and C18 as carbon chain distribution centers were obtained, which provided the possibility for further conversion and manufacture of diesel and lubricating oil.

　　These studies may still be proof of concept at the laboratory stage, but Xiaobian sincerely hopes that these methods of turning plastic waste into treasure can be commercialized on a large scale as soon as possible. Think about it. Convenient plastic products will no longer pollute our land and sea, but can become raw materials for producing fuel and value-added carbon products. In addition to transforming plastics, the best way to solve the problem of plastics is to prevent it from the source. In January 2020, we have promised to ban the use of disposable plastics. In the near future, we will be able to solve the plastic problem, save the earth's environment and give future generations a space for sustainable development.