Catalysis is critical to many chemical processes, from digesting your food to plastic production and making beer! Catalysts could drive the clean energy revolution and much more. In the first post of a three-part series, we explore what catalysts are and how they have been instrumental in human development, from world wars to pushing the frontiers of medicine.
By Aditya Sengar, Research Associate in the Department of Bioengineering.
Soma, the Elixir of Life, Chi, Manna, Prana, the Philosopher’s Stone, Shewbread, King Solomon’s gold... These are the many names alchemists of the past gave to a mysterious material with magical properties. Fans of Harry Potter and the Fullmetal Alchemist series will be familiar with the name of Nicolas Flamel. He was the French scribe who was widely believed to have discovered the philosopher’s stone and achieved immortality. Had Flamel been born half a millennium later, he would have been surprised to see the common use of these mystical arts in the everyday world. Yes, it is true! We have the Philosopher’s Stone and it has been public knowledge for a long time. I will help you out, if the title was not a giveaway. The magic is not in any material. It is in the process. I am talking about the science of catalysis. If you bear with me a bit longer, maybe by the end of my story, you will agree with me.
What is catalysis?
A catalyst helps a chemical reaction occur faster without participating itself in the reaction. Consider the biochemical reactions in the human body. The important metabolic reactions all require enzymes, which are biological catalysts. Without enzymes, breaking down food and generating energy from it would take about 2 billion years. Yes, you read that right. What your body does in a matter of minutes and hours could take a very long time if not for catalysis. Am I getting your attention now? I hope so.
Dawn of industrial catalysis
Before the modern era, using catalysts in one form or the other to produce products like wine, beer, soap, or cheese, was common. Let me ask you a question here. Can you guess the most important medicinal drug in human history? Not Penicillin, not insulin; but ether. Valerius Cordus in 1552 used sulphuric acid as a catalyst to produce ether. This revolutionised the medical world. It was originally used to treat bacterial and viral infections, but by the early 19th century, ether started being used as the default general anaesthetic. This period also saw the development of catalysis from empirics to science. In 1835, the term catalyst was first coined. The remaining part of the 19th century saw the exploitation of scientific knowledge for industrial applications and financial gain.
Enter the World Wars
Fritz Haber, a German chemist, in 1909 showed that ammonia could be produced from nitrogen in the air using a metal catalyst. This allowed the mass production of fertilisers throughout the Western World. Interestingly, the process is not primarily remembered for its ability to tackle world hunger. During the First World War, Allied Forces blocked the export of Chile saltpetre (sodium nitrate, NaNO3) to Germany. The mineral was used to prepare explosives at that time. Germany quickly started to produce ammonia via the Haber process on a mass scale, using it instead of saltpetre to make their explosives.
The discovery of polyethylene (or polythene) was another major event. This was an accident and it became a top-secret British government project. Scientists at Imperial Chemical Industries accidentally produced a white and waxy substance in a series of high-pressure experiments in 1933. Soon large plants were set up to manufacture the waxy substance, named polyethylene, to be used as an insulating material for radar cables during the Second World War. The process itself was a closely guarded secret. It wasn’t until in the 1950s that Karl Ziegler and Giulio Natta developed a catalytic process to produce polyethylene at low pressure and temperature (the process was later reformed by Phillips Oil Company with the Philips catalyst) leading to a massive growth in the plastic industry. The global polyethylene market is currently valued at $180 billion.
From alchemy to catalysis
The western world never accepted alchemy as a modern science and shunned practitioners as occult scientists. Even Isaac Newton, one of the most influential scientists, practiced alchemy in secret. Before his time though, the differences between the two sciences were not as great. Abū Bakr al-Rāzī (854–925 CE), a Persian scholar, was a pioneering alchemist and physician of his time. He discovered sulphuric acid, and his alchemical work is said to have laid the foundations of modern-day chemotherapy for cancer treatment. Alchemy, the theory of transmutation of one substance to another, has come alive in the science of modern-day catalysis.