Research

With a high chemical energy density and zero harmful emissions when produced from renewable resources, hydrogen is set to become a major fuel of the future, bridging the gap between intermittent renewable supply and rapidly depleting fossil fuels. Hydrogen can be used across a wide range of applications, from portable electronics to energy distribution systems within the grid, as well as transportation. The single largest challenge remaining in its implementation is storage. Hydrogen may be stored as a gas, a liquid, or bonded within a solid material. The latter is the safest approach and has a relatively high volumetric capacity –a requirement for the practical use of hydrogen as a clean energy vector.

Many hydride materials can store hydrogen by absorbing it like a sponge. However, the next generation of materials rely on light materials that require very high temperatures >400 °C and/or pressures >200 bar to reversibly absorb or release hydrogen. At Merlin our approach to solve this problem is to engineer hydride materials “atoms by atoms” so we can accurately tailor their properties for given applications.

Metals such as Li, Mg and Al can safely deliver significant amounts of energy through their reaction with oxygen. These metals can also store significant amounts of hydrogen. Control of their properties will provide solutions for novel, clean and high density energy storage devices akin to batteries.

All-solid-state batteries with pure metal anode can solve the problem of conventional batteries (such as lithium-ion) having a limited energy density. The key challenge with this solution is ensuring the stability of pure metal anode against an electrolyte. Complex hydrides are promising candidates owing to their lightweight and excellent compatibility with metal anodes (Li, Na, and/or Mg). But the low ionic conductivity at room temperature limits their developments. At Merlin we have developed several methods to increase the ionic conductivity of complex borohydrides. Through our modification, the ionic conductivity of complex borohydrides can reach the practical application level (10-3 S/cm) at near room temperature.

Due to the efficiency of converting hydrogen to power, fuel cells have been widely investigated. The planar fuel cell design geometry is the typical geometry employed by most types of fuel cells since the planar design has a lower resistance compared with the other types of geometries. At Merlin, we aim to design the alternative planar polymer electrolyte membrane fuel cells (PEMFC) low costs, long-term durability, of ease of manufacturing and made from abundant components catalysts including enzymes (e.g. hydrogenase). We are now focused on designing and fabricating PEMFC with a special focus on their air-breathing planar configuration,including the development of better proton conducting membranes and platinum-free catalysts to drive the oxygen reduction and hydrogen oxidation reactions efficiently. We also develop new concepts to fully integrate these catalysts into advanced electrolyser concepts where paraisitc load is limited.

Hydride materials have the ability to deliver hydrogen in a reactive form and thus capabilities for activating molecules and their conversion into valuable products. At Merlin, our current efforts are focusing on the conversion of the small molecules into valuable chemicals. The aim is to achieve efficient catalysts capable of harnessing CO2 for gas flues, for example, with direct conversion into liquid hydrocarbons.

The major advantages of H2 combustion facilitated by catalyst are the absence of NOx (Nitrogen Oxide) emission and flashback, and this appears to be the best solution for the safe and clean combustion of hydrogen. The design of effective catalytic materials can enable the low-temperature flameless combustion of hydrogen. Our group is developing better catalysts for the safest combustion of hydrogen.

Metal hydrides can undergo shifts in their electronic properties as they absorb or desorb hydrogen. In a thin film configuration, a magnesium coating of a few nm will shift from a reflective state to a transparent state as hydrogen is absorbed. At Merlin, we are aiming to control the reaction so the thin film can be cycled more than 1000 times without deterioration. The coating is only transparent to visible light, hence, the technology could be used for climate control in buildings, i.e. reflective thin film helps to keep a room cool and transparent thin film to warm a room up.