One Gram of Material Covers 7,310 Square Meters Equal to 1.3 Football Fields

Figure | Organic-inorganic hybrid porous materials with ultra-high porosity and surface area Source: Science Journal

Although the pattern is still unclear, hydrogen energy vehicles, as clean and environmentally friendly vehicles, have been developed by many companies around the world and may become the mainstream in the future. However, hydrogen energy vehicles also have an obvious shortcoming, that is, it is difficult to make breakthroughs in hydrogen storage devices. Hydrogen is the lightest gas. If you carry 1 kilogram of hydrogen that can run 100 kilometers under normal temperature and pressure, you will have to carry a huge 11,000-liter airbag on top of the car. if your car is two meters wide, the airbag will be 5.5 meters long and 1 meter high. This picture is so beautiful, I really can't bear to look straight. The current solution is a hydrogen energy battery. Hydrogen is stored in the hydrogen battery at a high pressure of 700 bar. The pressure level is about 300 times that of car tires. This battery can carry 4 to 5 kilograms of hydrogen and can run about four or five hundred kilometers. Due to the high pressure, a special fuel tank is required to store hydrogen safely, which increases the manufacturing cost of the car.

This material is called aluminum-based ultra-porous metal-organic framework NU-1501-Al, developed by Professor Omar Farha of Northwestern University others. The material is based on the BET theory, gas molecules can be adsorbed on countless layers of skeleton materials, thereby expanding the "inner surface area" of solid materials. According to this theory, the internal surface area of ​​1 gram of cement after hardening can reach 156 square meters, and the internal surface area of ​​1 gram of activated carbon reaches 3000 square meters.

The aluminum-based ultra-porous metal material developed by Northwest University is constructed of organic molecules and metal ions or clusters. These clusters will self-assemble to form a multi-dimensional, highly crystalline porous skeleton. This material has millions of small holes in 1 gram, and the inner surface area reaches an astonishing 7,310 square meters, equivalent to the size of 1.3 football fields!

Using this material to store methane has exceeded the US Department of Energy's storage goal of 0.5 g / g. at 270K / 100 bar, 1 g of material can absorb 0.66 g of methane. When it fluctuates from 77k / 100 bar to the optimal temperature and pressure combination of 160k / 5 bar, 1 gram of this material can release 14 weight percent (wt%) hydrogen, up to 46.2 grams/liter. I understand that a 100-liter storage tank, that is, a 1-meter square and 10 centimeters high hydrogen battery, can meet the requirements of current hydrogen energy vehicles, but it is much safer. Researchers believe that this material is like a sponge, which can store a large amount of hydrogen and methane, and can deliver them to the car's engine at a pressure lower than that required by current hydrogen fuel cell vehicles, and is expected to become a good carrier for clean energy source.