Fuel cells are considered to be an ideal source of energy due to their high efficiency, mild operation process, zero emission and most importantly, unlimited renewable source of reactants.
Fuel cells are electrochemical energy converters that combine a fuel, usually hydrogen, with oxygen to directly generate electricity and a water by-product, with no intermediate steps in between. Fuel cells are much more efficient than a combustion engine, which uses a two-step conversion process, and if hydrogen is used as a fuel, there are zero emissions. They’re mostly employed today in the automotive industry, but they’re great for using stored energy from renewable sources as well.
There are six main electrolytes used in fuel cells: proton exchange membrane fuel cells (PEMFC), direct methanol fuel cells (DMFC), phosphoric acid fuel cells (PAFC), molten carbonate fuel cells (MCFC), solid oxide fuel cells (SOFC) and alkaline fuel cells (AFC).
Fig 1. Fuel cell technologies and applications; The Fuel Cell Industry Review 2021, E4Tech.
Portable applications: small ‘movable’ APUs (campervans, boats, lighting); Military applications (portable soldier-borne power, skid-mounted generators); Portable products (torches, battery chargers), small personal electronics (mp3 player, cameras).
Stationary applications: large stationary prime power and combined heat and power (CHP); Small stationary micro-CHP; Uninterruptible power supplies (UPS); Larger ‘permanent’ APUs (e.g. trucks and ships).
Portable applications: materials handling vehicles; Fuel cell electric vehicles (FCEV); Trucks and buses; Rail vehicles; Autonomous vehicles (air, land or water).
There are two indispensable components to a fuel cell: a catalyst and a proton exchange membrane. The idea is to use a catalyst to break the hydrogen atoms into electrons and hydrogen protons. The electrons, blocked by the membrane, travel through a circuit, and generate an electrical flux, while the protons, small enough to pass through the membrane, join with the oxygen molecules on the cathode side and form water. These membranes aren’t failed safe though and most often then not, whole hydrogen atoms or methanol (or whatever fuel) can pass through and make the process less efficient.
A thorny issue for fuel is reducing the platinum loading as a catalyst material because of its cost and supply limitation. This issue can be overcome by designing catalysts with high electrocatalytic activity.
While platinum accounts for 40% of the costs of fuel cells, cost is not the limiting factor for wider adoption of fuel cells. The problem remains the cost of isolating hydrogen and developing an infrastructure for supplying hydrogen to individual vehicles.
Fig 2. Recent advances in graphene‐based materials for fuel cell applications. Energy Science & Engineering, Volume: 9, Issue: 7, Pages: 958-983, First published: 29 October 2020, DOI: (10.1002/ese3.833).
Graphene-based materials open new possibilities. In 2020, researchers at the University College London produced graphene via a special, scalable technique and used it to develop hydrogen fuel cell catalysts*. They showed that this new type of graphene-based catalyst was more durable than commercially available catalysts and matched their performance.
The combination of graphene as a structural support for metal oxide nanoparticles has shown a great profile for the ORR (Oxygen Reduction Reaction) and OER (Oxygen Evolution Reaction) in laboratory scale tests, which allows potential exploitation in this application.
Recently, transition metal oxide-based electrocatalysts have attracted tremendous attention suitable for the sluggish ORR and OER reactions due to their high activity. Other factors that promote their utilisation include low cost, high availability, and the presence of variable oxidation states, attractive in replacing precious and low abundant platinum-based catalysts.
Gnanomat’s hybrid nanomaterials have been tested with alkaline fuel cell independent developers confirming suitability for use. The trend is the substitution of the platinum by non-precious metal catalyst and Gnanomat is developing a solution, offering a low-cost and affordable platinum-free electrocatalyst material to be integrated in the MEA (membrane electrode assembly) of an AFC (Alkaline Fuel Cell).
This ongoing development is also a very good example of how our materials are being tested in different applications, involving key commercial customers that can provide significant and relevant feedback.