Renault Shows Hi-Flex Clio FFV in Paris
Mercedes-Benz Premiers New Gasoline Direct Injection System for More Power and Lower Fuel Consumption

Hydrogen Storage in Organic Polymers

In another approach to developing a viable on-board storage system for hydrogen in vehicles, researchers in the UK have developed a purely organic polymer with microporous structures that can adsorb hydrogen via physisorption.

Research into using a microporous material for hydrogen storage tends to focus on materials such as zeolites or activated carbons, which have many molecular-size holes suitable for the containment and release of hydrogen.

By contrast, the molecular chains in most organic polymers are so flexible that they can form tightly packed structures. This means there are no cavities inside, and thus no appreciable internal surface onto which substances could be adsorbed.

The chemists constructed polymers from interlinked five- and six-membered rings. At defined points in the molecule, two five-membered rings are connected in such a way as to provide a contorted shape to the stiff macromolecular structures. The contorted molecules cannot pack together efficiently and leave gaps and interstices.

In reproducible synthetic steps, the researchers have produced chemically homogeneous materials—“polymers of intrinsic microporosity”—with a uniform distribution of pore sizes of 0.6–0.7 nm.

These ultrasmall pores can absorb and then release between 1.4 and 1.7% hydrogen by weight at liquid nitrogen temperatures. Depending on the selection of building blocks the researchers can produce insoluble networks or polymers that are soluble in solvents and can thus be processed into useful shapes.

The current rate of storage is far below the DOE target of 6% for 2010 and 9% by 2015.

In order for the PIMs to store enough hydrogen to be useful they must be optimized further by both chemistry and polymer processing techniques. Neil McKeown of Cardiff University, one of the researchers, estimates that by 2010 they will have tailored a PIM capable of storing up to 6% hydrogen.



barry j hanson

Ethanol will store 13% by weight of hydrogen. Why worry about polymers, hydrides, or compressing it to 10,000 PSI for that matter?


Probably because you then have to have an on board reformer to crack the ethanol. Most of the FCV designs have moved away from an onboard reformer, I think, because the efficiency is not good.


There are examples of Direct Methanol Fuel Cell(DMFC), no reformer involved, although the energy output is too small to implement on a vehicle but it is still possible. Someday we might a FCV that use pure ethanol as fuel, or even have flex fuel ability.

Yeah, that should be the direction, FCV that uses liquid fuel.


send me constructional fetures of this system


best medical discount


best medical discount


best medical discount

The comments to this entry are closed.