Spinach could be the key to lowering fuel cell costs?

Fuel cells are expected to be applied as an energy source with high power generation efficiency, but the high cost of manufacturing materials was an obstacle to the spread. Research to use spinach to reduce the cost of such ingredients is being conducted by a research team at American University.

In practical fuel cells, platinum is used as an electrode catalyst capable of realizing high power generation efficiency. However, since platinum is rare and expensive, the fuel cell itself has become expensive, which is a cause of impeding the supply of fuel cells. In order to lower the cost, many research teams have been working on platinum replacement catalysts, but most of them have not been put into practical use because they are not cost effective.

Among these, the research team chose spinach as an inexpensive material to replace platinum. Conducting research on producing high carbon catalysts that can be used in fuel cells based on spinach purchased at local supermarkets.

The reason spinach was selected as the material was because of its high iron and nitrogen content. One of the reasons is that spinach is a renewable biomass resource. Spinach is cheaper than platinum, and it’s not difficult to grow it. This means that it is advantageous in terms of sustainability.

Making a catalyst based on spinach is like making a smoothie. To catalyze spinach, first wash fresh spinach leaves, grind in a mixer, and freeze-dry to a liquid state. Then, break freeze-dried to powder and add melamine as a nitrogen accelerator. In addition, sodium chloride and potassium chloride are added and pyrolyzed several times at a high temperature of 900°C to produce a catalyst in the form of nanosheets.

According to the research team, by adding sodium chloride and potassium chloride, the nanosheets can be made porous with many small pores. With this porosity, oxygen required for fuel cells can be transmitted.

The research team said that spinach catalysts are promising, but they say that the road to practical use is long and that research so far is only proof of principle. It is revealed that there are many tasks to be solved for practical use because there is a possibility that the result may be deteriorated if it is implemented in an actual device even if it shows excellent results in the commercialization stage.

Sustainability, which is one of the challenges, requires high heat of 900 degrees Celsius to produce a spinach catalyst, so heat generation leads to carbon dioxide emissions, and energy efficiency improvement in the manufacturing process is a challenge. Another challenge is that spinach catalysts can obtain higher performance than platinum catalysts as the hydrogen ion concentration is closer to alkali, but the efficiency decreases as they are closer to acidity. It is also a challenge to maintain spinach catalyst efficiency regardless of the hydrogen ion concentration.

The research team has already completed a prototype of the spinach catalyst and is in the process of actually testing the fuel cell spinach catalyst. However, since there is no know-how in the related field, we plan to conduct joint research with other places for the spinach catalyst test. Related information can be found here .