For the first time,researchers from Stockholm University in Sweden have studied the surface properties of iron and plutonium catalysts when nitrogen and hydrogen generate ammonia.This achievement opens the door for a better understanding of the catalytic process,finding more efficient materials,and the green transformation of the chemical industry.The results were published in the January 10 issue of the journal Nature.
  Hubble process is a method of producing ammonia through nitrogen and hydrogen.The annual output of ammonia produced by this method is 110 million tons,and ammonia is one of the basic chemicals for the production of chemical fertilizer.In 2001,the journal Nature proposed that Hubble method was one of the most critical scientific inventions of mankind in the 20th century.Thanks to Haber method,large-scale production of chemical fertilizers has prevented mass starvation and saved about 4billion lives.
  However,under the real conditions of ammonia production,scientists have not been able to conduct experimental research on the surface characteristics of catalysts by surface sensitive methods.The experimental technology with surface sensitivity at high enough pressure and temperature has not yet been realized.Anders Nelson,a professor of chemical physics at Stockholm University,said that the different assumptions about whether the state of iron catalyst is metal or nitride,as well as the nature of intermediate species important to the reaction mechanism,could not be clearly verified.
  The researchers have built a photoelectron spectrometer to study the surface characteristics of the catalyst under high pressure.Therefore,they can observe what happens when the reaction occurs directly,detect the reaction intermediates,and provide evidence for the reaction mechanism.The new instrument opens a new door for understanding ammonia production catalysis.
  Researchers said that the new tool could develop new catalyst materials for ammonia production.These materials can be better used with hydrogen produced by electrolysis to realize the green transformation of the chemical industry.