Issue 18/2016 - "Activated nitrogen transfer" makes it possible to synthesize ammonia at low temperatures

"Activated nitrogen transfer" makes low-temperature ammonia synthesis possible
Researcher Chen Ping and Dr.
Guo Jianping of the National Laboratory of Clean Energy of the Dalian Institute of Chemical Physics, Chinese Academy of Sciences, have made important progress
in the research of catalytic synthesis of ammonia.
They proposed the catalyst design strategy of "double active center", and developed a series of composite catalyst systems composed of transition metals and lithium hydride to realize the low-temperature catalytic synthesis
of ammonia.
According to China's national conditions, the development of low-temperature, low-pressure and high-efficiency synthetic ammonia catalysts is of great strategic significance
.
The results were recently published in the journal Nature Chemistry
.

The researchers introduced lithium hydride as the second component into the catalyst, constructed the "transition metal-lithium hydride" double-active center composite catalyst system, and proposed the reaction mechanism of "activated nitrogen transfer", so that the activation of nitrogen and hydrogen and the adsorption of intermediate species occurred on different active centers, thereby breaking the limiting relationship between the reaction energy barrier and the adsorption energy on a single transition metal, and making the low-temperature and low-pressure synthesis of ammonia possible
。 The experimental results show that the addition of lithium hydride has a significant effect on the activity of the third-cycle transition metals, especially the Fe-LiH and Co-LiH composite catalysts show considerable catalytic activity of ammonia synthesis at 150 °C, showing the effectiveness and universality of
the "double active center" strategy.