The problem with most current hydrogen sensor designs is that they are built on rigid substrates, which cannot be bent, and therefore, their applications might be limited due to the mechanical rigidity. In addition, they use expensive, pure palladium. A new type of sensors is bendy and use single-walled carbon nanotubes to improve efficiency and reduce cost. In the example of the space shuttle, laminating a dense array of flexible sensors on the whole surface of a pipe can detect any leakage of hydrogen prior to diffusion and alert control units to remedy the malfunction.
Back in January, when the U.S. president announced his hydrogen fuel initiative and proposed to spend a total of $1.7 billion over the next five years to develop hydrogen-powered fuel cells, hydrogen infrastructure and advanced automotive technologies, he said that it will be practical and cost-effective for large numbers of Americans to choose to use clean, hydrogen fuel cell vehicles by 2020. According to the U.S. Department of Energy's (DOE) Hydrogen Program, the government's goal is to achieve "technology readiness" by around 2015 in order to allow industry to make decisions on commercialization by then. That's only eight years to go. Given where the technology is today, this goal seems very ambitious, to say the least. Nanotechnology could help speed up the journey to the hydrogen society, but it will take some sensational breakthroughs on the way. The three key areas for the vehicles (we will not touch on the infrastructure issues here) are clean - the emphasis is on clean - hydrogen production, hydrogen storage, and the fuel cell itself. We'll take a look at how nanotechnology will play a role in these areas.
Fuel cells are electrochemical energy conversion devices for the direct conversion of the chemical energy of a fuel into electricity. They are among the key enabling technologies for the transition to a hydrogen-based economy. Of several different types of fuel cells under development today, polymer electrolyte fuel cells (PEFCs) have been recognized as a potential future power source for zero emission vehicles. However, to become commercially viable, PEFCs have to overcome the barrier of high catalyst cost caused by the exclusive use of platinum and platinum-based catalysts in the fuel-cell electrodes. Researchers at Los Alamos National Laboratory now demonstrate a new class of low cost (non-precious metal)/(heteroatomic polymer) nanocomposite catalysts for the PEFC cathode, capable of combining high oxygen-reduction activity with good performance durability. The results of their study show that heteroatomic polymers can be used not only to stabilize the nonprecious metal in the acidic environment of the PEFC cathode but also to generate active sites for oxygen reduction reaction.
Greatly expanding on previously reported work on platinum nanostructures, researchers at Sandia National Laboratories just released a new paper describing a range of novel platinum nanostructures with potential applications in fuel and solar cells as well as nanotags in biomedicine.
In the future hydrogen economy, hydrogen (H2) sensors will be a critical component for safety and widely needed. For example, H2 sensors will detect leaks from hydrogen-powered cars and fueling stations long before the gas becomes an explosive hazard.