One of the first concepts that we learn in school in chemistry is catalysis. The process of accelerating a chemical reaction using a catalyst, catalysis is a phenomenon that has been known since ancient times, but has been understood and utilised optimally only in the last 200 years or so.
The fact that the catalyst is not consumed in the reaction that is being catalysed means that it can continue accelerating the reaction repeatedly. As a result, only small quantities of catalysts are mostly required to alter the reaction rate. This has led catalysis to play a fundamental role in industry and research.
The beginnings of our understanding of catalysis can be traced back to a German chemist named Johann Wolfgang Dobereiner, who contributed to this cause and also made early inroads into what eventually became the periodic table of elements.
No formal education
Born in Hof an der Saale in 1780, Dobereiner was the son of a coachman and had limited means for any formal education. He started out as a pharmacist’s apprentice at the age of 14 and went on to set shop himself in a number of cities.
Aware of his educational shortcomings, he read widely and attended a large number of learned lectures. At the same time, he also tried his hand at a number of businesses to try and finance himself, but they all ended badly.
Goethe’s lifelong friend
He was, however, fortunate to come to the notice of Johann Wolfgang von Goethe, considered to be among the greatest literary German figures of the modern era. Goethe, who became Dobereiner’s lifelong friend, was able to obtain a professorship for Dobereiner at the University of Jena, where he rose through the ranks from 1810 until he died in 1849.
Dobereiner’s work in what is now known to be heterogeneous catalysis stemmed from his interest in platinum, which he required for producing chemically resistant vessels for the lab. The reactions that he tried out in 1821 helped him improve the making of vinegar and he was also able to give the correct explanation, attributing it to the activity of platinum as opposed to the existing belief that it was due to the action of ethanol on platinum.
Spontaneous fire
On July 27, 1823, Dobereiner made a remarkable observation when working with platinum sponge. When a jet of hydrogen mixed with air was directed on the sponge, the hydrogen caught fire immediately. Dobereiner noted that he could repeat the experiment, which took place at room temperature, at lower temperatures as well.
While creating a fire this way might seem unremarkable now, we must remember that there was still no easy way to produce fire in 1823 – using flint and tinder was still the dominant way of creating fire. Dobereiner’s discovery led him to an application that could be used for lighting purposes. The Dobereiner Feuerzeug (Dobereiner’s lamp) or hydroplatinic lamp or briquet a hydrogene (hydrogen lighter) was the go-to lighting gadget for decades, until it was finally replaced by, well yes, the matchstick.
Helps develop catalysis
Dobereiner’s discovery was a sensational hit and was tested out and confirmed by various physicists and chemists. Swedish chemist Jons Jacob Berzelius, seen as one of the founders of modern chemistry, wrote about it at the time as “the most brilliant discovery of last year”.
Dobereiner’s experiments, in fact, helped Berzelius in developing the concept of catalysis. It was Berzelius who coined the word “catalysis” in 1835, from the Greek words kata meaning down and lyein meaning loosen. Catalysis has become an indispensable part of chemistry since then and our understanding of the process has also been catalysed.
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Dobereiner’s triads
Dobereiner also directed attention to the fact that the properties of certain elements seemed to be midway between two others by 1829.
He identified triads – calcium, strontium, barium; chlorine, bromine, iodine; sulphur, selenium, tellurium – that exhibited these properties.
He was able to show that the mean of the lightest and heaviest atomic weights among these triads approximated to the atomic weight of the middle element.
These were seen as mere curiosities and Dobereiner was given his due for this only after Russian chemist Dmitri Mendeleev established the periodic table.
