Executive Summary: Oxidation-Reduction

Redox (or Oxidation-Reduction) reactions are ubiquitous to nature and can be observed throughout everyday life. A common example of this is when paper starts to turn yellow over time – this change is from oxidation caused by exposure to air and sunlight. Even fundamental, well-known reactions such as photosynthesis, could not be completed without redox reactions.

6CO2 + 6H2O + Sunlight/Chlorophyll → C6H12O6 (carbohydrate) + 6O2

Simply put, when something is oxidised, it loses electrons and when something is reduced, it gains elections. In the above example, sugar and oxygen are created when water molecules are reduced, providing electrons to form carbon dioxide. To dive in a little deeper, oxidation reaction pathways can be categorised and defined as chemical reactions in which oxygen atoms combine with other elements, resulting in the removal of electrons from the original substance - a process in which oxygen gas is formed.

However, not all important redox reactions require oxygen. For example, ammonia (NH3) is a common redox-produced chemical that does not contain oxygen. To create NH3, a redox reaction known as the Haber process is applied, in which nitrogen and hydrogen are combined under a pressure of about 200 atmospheres at around 500°C in the presence of an iron catalyst. In this instance, nitrogen is oxidised while the hydrogen is reduced. This reversible redox process results in ammonia, which is used to produce many essential compounds such as dyes, cleaning solutions and polymers. The Haber process can be summarised as follows:

N2 + 3H2 ↔ 2NH3

For many years, Umicore has applied its scientific expertise to explore and advance redox reactions, aiming to drive innovation across a multitude of markets by utilising expertise in catalysis and process development for any reaction that our customers require. There are several applications in which our portfolio can be utilised to drive cleaner, faster redox reactions. 

Oxidation on the move 

Many industries rely heavily on oxidation reactions, i.e. where the oxidised molecule is the desired end product. One example of this is the fuel cell industry. Here, oxidation forms an essential component of the technologies in which hydrogen gas is oxidised, before recombination with oxygen to generate electricity and water. However, traditional oxidation reactions pose a significant challenge at industrial scale due to outdated and inefficient methods.

In order to modify your systems to improve sustainability and efficiency, it is important to understand the underlying principles and current limitations of oxidation catalysis. These considerations include addressing issues of O2 activation, the role of additives, catalyst selectivity and deactivation, leveraging that knowledge to develop safe, efficient and flexible processes.

Within Umicore Precious Metals Chemistry’s unrivalled list of oxidation offerings, some noteworthy examples of their applications include the removal of pollutants, carbonylation, integrating oxygen into molecules, and many more. You can find out more about this range of products here.

Reduction, Reduction, Reduction

Oxidation cannot occur without the simultaneous reduction step at the same time. In industrial reduction reactions, reactions can be manipulated to produce a variety of desired, valuable chemicals and products at a considerably lower cost than if manufactured with conventional techniques.

Facilitated with metal catalysis, Umicore has developed an extensive list of applications for reduction reactions. Notably, these include both hydrogenation and hydroamination reactions, as well as water electrolysis. In water electrolysis reactions, which can be used to create hydrogen fuels, reduction reactions are commonly used, occurring at the interface of the cathode where hydrogen ions are converted into hydrogen gases. 

Outside of fuel cell technologies, reduction also plays a vital role in the automotive industry within catalytic converter technologies. Here, these reactions are used to eliminate harmful nitrogen oxide molecules (NOx), by reducing them to safer nitrogen gas and water. This reaction, mediated by our platinum catalysts, helps generate cleaner air for a more sustainable future.

Redox for the future

As industries all over the world continue to move towards a standardised, more sustainability-focused business model, many of the most commonly-applied chemical processes will require alteration or adjustment. Umicore Precious Metals Chemistry has a long history of sustainability and is an ideal partner for those who wish to improve the financial and environmental sustainability of their work, whilst catalysing their reactions for cleaner, quicker processes.

Sustainability is at the heart of everything we do at Umicore Precious Metals Chemistry and this drives us to offer efficient catalysts for use in automotive applications. Whether you need reduction catalysts for fuel cells or hydrogenations, or rhodium and ruthenium catalysts for oxidation reactions, we can help to create your ideal chemical solutions.

Get in touch to talk about how we can co-create chemistry together or browse our range of products here.