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Researchers improve the electrocatalysts for hydrogen evolution

June 23, 2017
  L M S

Hydrogen production through the process of water electrolysis can, on a large scale, convert electrical energy generated by renewable energy into easily stored chemical energy, which plays an important role in renewable energy conversion and chemical production. However, it has shortcomings such as high over-potential and low hydrogen production activity due to the use of cheap transition metal as electrode material. So, to improve the overall performance of electrocatalysts in achieving a high level of efficient and stable hydrogen production, adopting the specific scientific method of "adding" other elements to modulate the electronic structure and surface properties of the electrode material has become a research focus in the catalysis and materials field.

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Recently, researchers from XJTU and City University of Hong Kong experimented to add the element Ceriumin cobalt phosphide through a simple chemical method to reduce the hydrogen adsorption energy on the surface of cobalt phosphide and to improve the surface charge characteristics, which greatly enhanced the hydrogen production activityof the catalyst. Theoretical calculation demonstrates that cerium addition to the surface of cobalt phosphide can improve the electronic structure of the active center, reduce the hydrogen adsorption energy on the surface of cobalt phosphide, and lower the reaction barrier for hydrogen generation, thus speeding up the hydrogen evolution rate of the catalyst. The experimental results further confirmed that cobalt phosphide with cerium added creates more catalytic activity points, higher conversion frequencies and better charge transport characteristics compared to cobalt phosphide with no cerium added. The electrocatalytic activity in acidic and alkaline media of the former greatly improves and can maintain good stability. This method of improving the hydrogen production activity of the electrocatalysts by introducing rare earth elements has referential significance for understanding the effect of rare earth elements on other transition metal catalysts and further improving the activity of electrocatalysts.

The above results were published with an article titled"Modulating electronic structure of CoP electrocatalysts to enhance hydrogen evolution by Ce chemical doping in both acidic and basic media"in Nano Energy (impact factor11.553) on June 3.

The current research activity of Professor Qu Yongquan's research group focuses on the application of multi-scale materials in the field of catalysis, including high temperature catalysis, photocatalysis, nano-organic catalysis and electrocatalysis (OER and HER).