Dancing on Pine Needle Tip—— Significant Evolution of Catalyst Structure for Hydrogen Generation by Water Electrolysis
 2019-06-06  Font Size:[ Large Medium Small ]

Energy is the eternal theme of civilization. Hydrogen energy, as an efficient clean and renewable energy, is one of the hottest issues in this century. Hydrogen generation by water electrolysis has attracted more and more researchers' attention because of its advantages of zero pollution and zero emission. As one of the key links, various new catalytic materials emerge in endlessly. Recently, Prof. SONG Li from National Synchrotron Radiation Laboratory, University of Science and Technology of China (USTC), and Prof. JIANG Jun from USTC, worked together to bring pioneer new ideas. Using platinum metal with the best catalytic effect, they ingeniously designed a pin-point catalyst with pine-ball structure. Compared with commercial platinum-carbon catalysts, the amount of platinum metal was reduced by nearly 75 times and the cost of catalysts was greatly reduced while the catalytic hydrogen production remained almost unchanged. The research results were published online in Nature Energy on June 3th.

In University of Science and Technology of China which near Yellow Mountain, Anhui, Prof. SONG Li and Prof. JIANG Jun collaborated to design the structure of platinum atom catalyst ingeniously, which greatly improved the hydrogen generation efficiency of electrolytic solution when it passed through pinpoint catalyst pine ball. (Image by: LI Jin)

In the story of The story of the stone, a few people are busy working in Jiafu, but there are still a lot of people with no duty which consumes the cost and nothing comes out. Similar problems exist in traditional catalysts. Catalytic processes generally occur on the surface of catalysts and involve a single or several neighboring atoms. So the platinum atoms on the surface manufactured in the traditional way are very busy, while the platinum atoms inside have contributed few. How to make the inner platinum atoms in the catalyst move without eating from the same pot?

Prof. SONG Li's team has come up with a good way to maximize the platinum atoms on the surface of the catalyst. Firstly, compared with previous studies, they chose the sphere with the largest surface per unit mass, and made the flat catalysts into spheres one by one, transforming the previously confined two-dimensional reactions into three-dimensional. Once a small bungalow was transformed into a spherical high-rise, and the number of people that could be accommodated — that is, the site where reactions could take place— increased greatly. At the same time, each platinum atom is located on the spherical surface, which ensures that they are on the production line. In this way, the catalyst forms a ball full of needle tips, each of which is a single atom of platinum, and no human can hide behind. Prof. JIANG Jun said: This design also brings a surprising additional effect. Theoretical simulation shows that the curved sphere will form a very strong local electric field at the tip of the platinum atom, which is equivalent to adding an accelerating track to the foot of platinum atom, resulting in further enhancement of the catalytic efficiency.            

The rate of hydrogen formation increases greatly when the reactants in the electrolytic solution pass through the loose balls of needle tips on one surface after another.  Prof. SONG Li said: With the same hydrogen production, the catalyst we designed only needs one platinum, while the traditional commercial platinum-carbon catalyst needs seventy or eighty platinum, which greatly reduces the cost of the catalyst.            

Reviewers highly praised: This is a rather complex study on monoatomic catalysts. The author adjusts the charge and local electric field through dimension design to improve the catalytic effect of platinum atoms. I appreciate these interesting ideas.”           

Platinum metal plays an important role in hydrogen generation by water electrolysis reaction. This work minimizes the amount of platinum but does not affect the catalytic effect of hydrogen evolution reaction. It is expected to achieve large-scale application. In addition, the relationship between the effect of catalyst and its structure is deeply understood, which points out the direction for further optimizing the performance of catalyst.

Paper link: https://rdcu.be/bFvwG

(Written by FAN Qiong, Translated by YANG Xinqi, edited by LIN Yujie, USTC News Center)

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