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According to foreign media reports, scientists have long known that platinum is the best catalyst for hydrogen production from water decomposition. A new study by researchers at Brown University shows why the precious metal is so effective, and the results are not what people think. (photo source: Brown University) according to the author of the paper, the research has helped solve a problem that has plagued us for nearly a century, and has helped design new catalysts that are cheaper and richer than platinum to produce hydrogen, which may help reduce fossil fuel emissions. Andrew Peterson, associate professor at Brown University School of engineering and lead author of the study, said: "if we can find a cheap and effective way to produce hydrogen, we can open the door to many practical solutions without fossil fuels and chemicals. Hydrogen can be used for fuel, but it can be used for hydrogen powered vehicles. It can be combined with excessive carbon dioxide to make fuel. It can be combined with nitrogen to make ammonia fertilizer. It can use hydrogen to do many things. If we want to decompose water to make hydrogen, we need a cheaper catalyst. " Peterson said that to design new catalysts, we need to understand what makes platinum so special in such reactions, which is the purpose of the new study. For a long time, platinum has been used as a catalyst to decompose water for hydrogen production so successfully because it has the binding energy of "blonde girl" criterion (just right is the most suitable one). The ideal catalyst needs to be in the reaction so that the molecules are neither too loose nor too compact, but just moderate. If the molecule is too loose, it will be difficult to start the reaction; if it is too tight, the molecule will stick to the catalyst surface, making the reaction difficult to complete. The combination of hydrogen can perfectly balance the two parts of water decomposition reaction in platinum, so most scientists think that's why platinum is a good catalyst. But Peterson said there was reason to question whether it was true. For example, a substance called molybdenum disulfide (MoS2) has a binding energy similar to that of platinum, but its catalytic effect is much worse than that of platinum in the water decomposition reaction. Therefore, the binding energy is not the whole reason. To find out what happened, Peterson and his colleagues studied the performance of platinum catalysts in the water decomposition reaction. They developed a special method to simulate the behavior of individual atoms and electrons in the electrochemical reaction. The analysis shows that when the reaction rate is high, the hydrogen atoms on the surface of platinum with the binding energy of "Blonde" criterion do not participate in the reaction at all. Instead, such atoms inhabit the crystalline layer of platinum's surface and are inert bystanders (not involved in the reaction). The hydrogen atom involved in the reaction is much weaker than the assumed binding energy of the "blonde girl" criterion. This kind of hydrogen atom does not reside in the lattice, but sits on the platinum atom, and can meet freely to form hydrogen. The researchers concluded that it was the free movement of hydrogen atoms on the surface of platinum that made platinum so active. "This tells us that looking for a" blonde girl "combination is not the right way to design high activity regions, and we suggest designing a catalyst that allows hydrogen to be highly mobile and active," Peterson said The Peterson lab at Brown University, which uses computer simulations to design new catalysts, plans to use the new findings to start looking for alternatives to platinum.