A little talked about element, with the atomic mass 140, plays a surprisingly important role in everyday life. It has not only lit many a path, but can be credited with improving and saving the lives of billions of people by enabling cleaner air.
In his talk '140Ce: White light & Clean Air' Andy Walker, Johnson Matthey’s Technical Marketing Director explained why the soft, ductile silvery-white metal Cerium, deserves more recognition.
Walker began by outlining the history of SCI, celebrating its 140th anniversary this year. As an employee of Johnson Matthey, Walker highlighted that George Matthey was among the pioneers of SCI. In addition Walker explained that his PhD research had involved looking at catalysts that included Cerium.
Cerium is a lanthanide and the 26th most abundant element on earth. Indeed it was the first lanthanide to be discovered, found as its ore cerium silicate, in 1803. Cerium makes up 66ppm of the earth’s crust, which is about 5 times as much as lead. It is the only one of the lanthanides able to take on the +4 oxidation state, making it very useful in some of its applications. It is mined in the US, Brazil, India, Sri Lanka, Australian and China, with annual global production of 24 000 tonnes.
However, this straightforward look at the history of Cerium conceals a much more interesting narrative about how this element shaped the life of a number of prominent chemists of the day. Indeed Cerium was found as early as 1751 at a mine in Vestmanland, Sweden by Axel Cronstedt, who also discovered Nickel. Believing it to be an ore of Tungsten, he sent it to Carl Wilhelm Scheele for analysis. However, Scheele was not able to identify it as a new element.
This turn of events for Scheele, perhaps unfairly, helped to seal his moniker as the ‘unlucky chemist’. Scheele, a prominent chemist and pharmacist, had a number of discoveries to his name. He isolated lactic acid, and discovered hydrogen fluoride and hydrogen sulphide.
But as Walker explained, his most notable discovery was oxygen, some three years before Joseph Priestley. Sadly for Scheele; it took him six years to publish his findings, by which time Priestley had already presented his data. Putting a contemporary slant on Scheele’s misfortune, Walker added that the cautionary tale here was that getting things out into the public domain as soon as possible can be important to ensure credit goes to the right people.
Further work by Scheele led to the discovery of a number of elements including barium and chlorine, but sadly he did not receive any recognition because he didn’t manage to isolate them and identify them correctly. The chemist Sir Humphrey Davy did so, some years later, getting the credit for their discovery and isolation.
So it was in 1803 that chemists Wilhelm Hisinger and Jons Jacob Bezelius proved that Cerium was indeed a new element, naming it Cerium after an asteroid/dwarf planet which had been called Ceres. The successful isolation of Cerium took place in 1875, carried out by American chemists William Hillebrand and Thomas Norton, by passing an electric current through molten cerium chloride.
99.95% fine cerium isolated on white background
Once isolated, the earliest application of Cerium was in incandescent gas mantles. Developed by Carl Auer von Welsbach, in 1891, he perfected a mixture of 99% thorium oxide and 1% ceria, which gave a soft white light. Introducing his new mantle commercially in 1892, von Welsbach was able to monetise his development selling his product throughout Europe.
Gas mantles have been replaced, but Cerium’s importance in producing white light remains. As Walker explained, most white LEDs use a blue gallium nitride LED covered by a yellowish phosphor coating made of cerium-doped Yttrium Aluminium Garnet crystals.
In the medical arena, Cerium was used by Sir James Young Simpson, Professor of Medicine and Midwifery at Edinburgh who did a lot of work in the area of anaesthetics. Simpson found that cerium nitrate suppressed vomiting, particularly that associated with morning sickness, and well into the last century, medication containing Cerium could be bought over the counter. In addition Cerium has been the basis of treatments for burns.
Other applications for this versatile element are self cleaning ovens and mischmetal alloy, used in flints for cigarette lighters. Walker shared that the chemist and author Primo Levi, while imprisoned in Auschwitz, was able to steal cerium-iron rods from the laboratory he was forced to work in. Making them into cigarette lighter flints, he was able to barter for bread. Cerium is used to harden surfaces; it is a good polishing agent. Cerium sulphide has been used to replace the pigment cadmium red as a non-toxic alternative and Cerium is widely used across the chemical industry as a catalyst to produce a host of chemicals.
Catalysis is probably where Cerium has impacted most people as the element is the basis for the catalytic converters that have provided cleaner air for billions of people. Walker explained that the driver for the development came during the 1950s when photochemical smog was a problem in the Los Angeles Basin. Measurements at the time indicated that vehicles were responsible for the majority of the hydrocarbon and NOx emissions that led to the polluted air.
This turn of events led researchers to develop systems that could mitigate the emissions. Johnson Matthey was among those doing the early work on catalytic converters. Meanwhile, the automotive industry was pushing back on their introduction, concerned about the costs, durability and effectiveness. Working with Ricardo Engineering, Johnson Matthey carried out durability tests over 25 000 miles which also showed that the catalysts could pass US emissions tests.
The catalysts had to operate in three ways, at the same time, oxidising carbon monoxide (CO) and hydrocarbons (HC) while reducing NOx. Early catalysts, circa 1975, were based on Palladium and Platinum and focused on oxidising the CO and HC. Around 1978 a second catalyst was introduced to reduce NOx.
However, the introduction of Cerium then made it possible to develop a single catalyst that was able to carry out the functions that the researchers had wanted to achieve. Hence, 1981 saw the introduction of the three way catalytic converter with all three reactions enabled over a single catalyst. More recently ceria-zirconia oxide based catalysts have been developed with much higher oxygen storage capacity than ceria.
The impact of these developments has allowed the implementation of much more stringent air quality and emissions standards. Indeed Johnson Matthey estimates that its Cerium-based catalysts are responsible for removing around 40 tonnes of pollutants every minute of every day.
A single element has indeed impacted many lives.
Who is Dmitri Mendeleev?
Russian chemist, Dmitri Mendeleev was born in 1834 in a Siberian village. His early life has been described as tumultuous; his father lost his sight and died when Dmitri was thirteen, leaving his family in financial difficulties.
His mother prioritised Dmitiri’s academic potential, taking him and his sister to St Petersburg, where he studied at the Main Pedagogical Institute. When his mother died, he carried out his doctoral research in St Petersburg where he explored the interactions of alcohols with water.
Between 1859 and 1861 he went to Paris to study the densities of gases, and he travelled to Germany where he studied capillarity and surface tension that subsequently led to his theory of ‘absolute boiling point.’ In 1861 he returned to Russia to publish everything he knew on organic chemistry in a 500-page textbook, and by 1864 he became a professor at the Saint Petersburg Technological Institute and Saint Petersburg State University.
As he continued his research, he tried to classify the elements according to the chemical properties. He became aware of a repeating pattern – elements with similar properties appeared at regular intervals. He arranged the elements in order of increasing relative atomic mass and noticed the chemical properties of these elements revealed a trend, which led to the formation of the periodic table.
Beyond his work in chemistry, during the 1870s, he devoted time to help the Russian industry, particularly in strengthening the productivity in agriculture. He became very active in exploring the Russian petroleum industry and developed projects in the coal industry in the Donets Basin. Additionally, he was responsible for creating and introducing the metric system to Russia.
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog focuses on Beryllium.
Beryllium copper alloys account for a huge percentage of the beryllium used in the United States. As these alloys are good conductors of electricity and heat, they are used in making connectors, switches and other electrical devices for use in many sectors including aerospace, automobile, computer, defense and medical.
Beryllium metal is very light and stiff and maintains its shape in both high and low temperatures. This makes it the ideal material for use as mirrors of the Spitzer Space Telescope and the James Webb Space Telescope (JWST), due to be launched in the next few years. The key mirror of the JWST comprises 18 hexagonal segments- each must maintain its shape even at - 400 degrees Fahrenheit.
Automobile and Aircraft
Additionally, Beryllium alloy connectors are used in the electrical systems of automobiles, as they are reliable and improve vehicle fuel efficiency.
In commercial aircraft, the strength of beryllium copper provides many advantages, as it can handle wear forces and exposure to corrosive atmospheres and temperatures. Beryllium copper also allows bearings to be made lighter and smaller, which also improves fuel efficiency.
Beryllium copper’s strength and stability makes it ideal for medical technologies and x-ray equipment.
As imaging technology progresses, beryllium copper will continue to play an important role in x-ray tube windows.
Other medical uses of beryllium:
•Springs and membranes for surgical instruments
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today, we investigate the uses of platinum.
Around 1200BC, archaeologists discovered traces of platinum in gold in ancient Egyptian burials.
However, the extent of Egyptians’ knowledge of the metal remains unknown, which suggests that Egyptians might have been unaware that platinum existed in the gold.
The Ancient Egyptians made elaborate masks for royals to wear once they were mummified.
Platinum was also used by South Americans with dates going back 2000 years. Burial goods show that in the pacific coast of South America, people were able to work platinum, producing artifacts of a white gold-platinum alloy.
Archaeologists link the South American tradition of platinum-working with the La Tolita Culture. Archaeological sites show the highly artistic nature of this culture, with the artifacts characterised by gold and platinum jewellery, and anthropomorphic masks symbolising the hierarchical and ritualistic society.
What are its properties?
Platinum is a silvery white metal, also known as ‘white gold’. It is extremely resistant to tarnishing and corrosion and it is one of the least reactive metals, unaffected by water and air, which means it will not oxidise with air.
It is also very soft and malleable, and therefore can be shaped easily and due to its ductility, it can be easily stretched into wire.
Platinum is a member of group 10 of the periodic table. The group 10 metals have several uses including decorative purposes, electrical components, catalysts in a variety of chemical reactions and play an important role in biochemistry, particularly platinum compounds which have widely been used as anticancer drugs.
Additionally, platinum’s tarnish resistance characteristics makes it one the most well-suited elements for making jewelry.
Platinum bonds are often used as a form of medicine in treatments for cancer. However, the health effects of platinum are dependent on the kinds of bonds that are formed, levels of exposure, and the immunity of the individual.
In 1844, Michele Peyrone, an Italian chemist, discovered the anti-neo plastic properties (apparently prohibiting the development of tumours) and later in 1971, the first human cancer patient was treated with drugs containing platinum.
Today, approximately 50% of patient are treated using medicine which includes the rare metal. Scientists will look further into all the ways platinum drugs affect biology, and how to design better platinum drugs in the future.
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today, on International Women’s Day, we look at the two elements radium and polonium and the part Marie Curie that played in their discovery.
Who is Marie Curie?
Marie Sklodowska and her future husband Pierre Curie.
Marie Sklodowska-Curie was born in 1867 in Poland. As a young woman she had a strong preference for science and mathematics, so in 1891 she moved to Paris, France, and began her studies in physics, chemistry and mathematics at the University of Paris.
After gaining a degree in physics, Curie began working on her second degree whilst working in an industrial laboratory. As her scientific career progressed, she met her future husband, Pierre Curie, whilst looking for larger laboratory space. The two bonded over their love of science, and went on to marry, have two children and discover two elements together.
After finishing her thesis on ‘Studies in radioactivity’, Curie became the first woman to win a Nobel Prize, the first and only woman to win twice, and the only person to win in two different sciences.
Curie, along with husband Pierre and collaborator Henri Becquerel, won the 1903 Nobel prize in Physics for their radioactivity studies, and the 1911 Nobel prize in Chemistry for the isolation and study of elements radium and polonium.
Curie won the Nobel prize twice in two different subjects. Image: Pixabay
As of 2018, Curie is one of only three women to have won the Nobel Prize in Physics and one of the five women to be awarded the Nobel Prize in Chemistry.
Polonium, like radium, is a rare and highly reactive metal with 33 isotopes, all of which are unstable. Polonium was named after Marie Curie’s home country of Poland and was discovered by Marie and Pierre Curie from uranium ore in 1898.
Polonium is not only radioactive but is highly toxic. It was the first element discovered by the Curies when they were investigating radioactivity. There are very few applications of polonium due to its toxicity, other than for educational or experimental purposes.
Radium is an alkaline earth metal which was discovered in the form of radium chloride by Marie and her husband Pierre in December 1898. They also extracted it from uranite (uranium ore), as they did with polonium. Later, in 1911, Marie Curie and André-Louis Debierne isolated the metal radium by electrolysing radium chloride.
The discovery of radium led to the development of modern cancer treatments, like radiotherapy.
Pure radium is a silvery-white metal, which has 33 known isotopes. All isotopes of radium are radioactive – some more than others. The common historical unit for radioactivity, the curie, is based on the radioactivity of Radium-226.
Famously, radium was historically used as self-luminescent paint on clock hands. Unfortunately, many of the workers that were responsible for handling the radium became ill – radium is treated by the body as calcium, where it is deposited in bones and causes damage because of its radioactivity. Safety laws were later introduced, followed by discontinuation of the use of radium paint in the 1960s.
Marie Curie: A life of sacrifice and achievement. Source: Biographics
Curie’s work was exceptional not only in its contributions to science, but in how women in science were perceived. She was an incredibly intelligent and hard-working woman who should be celebrated to this day.
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog is about sulphur, specifically sulphites and their significance to the wine industry.
Sulphites and wine - what is all the fuss about? Image: Pixabay
What is a sulphite?
Sulphites are compounds that contain the sulphite ion (sulphate (IV) or SO32- ). There a wide-range of compounds of this type, but common ones include sodium sulphite, potassium bisulphite and sulphur dioxide.
Sulphites are often added as preservatives to a variety of products, and help maintain shelf-life, freshness and taste of the food or drink. They can be found in wines, dried fruits, cold meats and other processed food. Some are produced naturally during wine-making however, they are mainly added in the fermentation process, protecting the wine from bacteria and oxidation.
Sneezing and wine
Sulphites have a bad reputation for causing adverse reactions, such as sneezing and other allergic symptoms. But are sulphites really allergens, or just another urban myth?
Despite it being one of the top nine listed food allergens, many experts believe that the reaction to sulphites in wine can be considered not a ‘true allergy’, rather a sensitivity. Symptoms only usually occur in wine-drinkers with underlying medical issues, such as respiratory problems and asthma, and do not include headaches.
Some people report sneezing and similar symptoms when drinking wine.
Sulphites are considered to be generally safe to eat, unless you test positive in a skin allergy test –some individuals, particularly those who are hyperallergic or aspirin-allergic, may have a true allergy to sulphites. Sufferers of a true allergy would not suffer very mild symptoms if they consumed sulphites, instead they would have to avoid all food with traces of sulphite.
Some scientists believe adverse reactions to red wine could be caused by increased levels of histamine. Fermented products, such as wine and aged cheese, have histamine present, and red wine has significantly more histamine than white wine. They suggest taking an anti-histamine around one hour before drinking to help reduce symptoms.
Despite it not being considered a true allergen, wine-makers must still label wine as containing sulphites. In 1987, a law was passed in the US requiring labels to be placed on wine containing a large amount of added sulphites. Similarly, in 2005, a European law was brought in to regulate European wine labelling. Sulphites are now often listed as a common allergen on bottle labels in wines that have over 10mg/l.
You can often find the words ‘contains sulphites’ on a wine bottle. Image: Pixabay
Many food and drink industries are producing products suitable for allergy sufferers, and winemakers have followed this trend by beginning to make sulphite-free wine. These are mainly dry red wines that contain high levels of tannins, which act as a natural preservative. Wines without added sulphites are generally labelled as organic or natural wines and have grown in popularity over the last few years, but unfortunately, many wine critics believe that these naturally preserved wines sacrifice on flavour and shelf life.
In summary, sulphites are a common preservative, not only found in wine, but a range of food, and do not generally cause allergic reactions. If you are an individual with a true sulphite allergy, you may want to try sulphite free wine – but you will have to compromise on shelf life!
2019 has been declared by UNESCO as the Year of the Periodic Table. To celebrate, we are releasing a series of blogs about our favourite elements and their importance to the chemical industry. Today’s blog is about one of the most abundant and most used elements, carbon!
Carbon could be called the element of life – it can be found in every living creature on Earth in a variety of different forms, from the backbone of your DNA, to the taste receptors in your tongue and the hormones controlling your hunger. Carbon-based chemistry surrounds us – in the air we breathe, in the food we eat and in the soil beneath our feet.
So, why is carbon so important to life? Carbon’s chemistry allows it to form large, intricate 3D structures, which are the basis of its interaction in biology – like jigsaw pieces that come together to build a tree, an elephant or a human being.
The study of carbon-based chemistry, or organic chemistry, has allowed us to better understand our living world and the interactions that occur, leading to development of better tasting food, higher yielding crops and more efficient medicines to improve our health.
In the early 19th century, chemist Justus von Liebig began synthesising organic, carbon-based molecules and said: ‘The production of all organic substances no longer belongs just to living organisms.’
Since then, hundreds of organic compounds for medicinal use have been synthesised – from adrenaline to ibuprofen – and hundreds of unique synthesis pathways have been described.
Organic chemistry – the study of carbon-based chemistry – has given us hundreds of modern medicines.
Carbon in materials
Atoms of carbon can make four bonds, each with another carbon attached, to arrange themselves into different molecular structures and form completely different substances. These molecular structures, known as allotropes, can result in vast differences in the end-result material.
For example, one allotrope, diamond, is the hardest and highest thermally conductive of any natural material, whereas another, graphite, is soft enough to be used in pencils, and is highly conductive of electricity.
Graphene is carbon allotrope that exists in thin, 2-dimensional layers, with the carbon atoms arranged in a honeycomb formation. Scientists had theorised its existence for years, but it was not isolated and characterised until 2004 by Andre Geim and Konstantin Novoselov at the University of Manchester, UK. The pair won the 2010 Nobel Prize in Physics for their work.
The structure of carbon atoms in graphene.
Graphene is a highly conductive, flexible and transparent – this means it can be used in electronics, medical biotechnology, and a variety of other innovative solutions.
Another innovative material made from carbon is carbon fibre, which can then produce carbon-fibre reinforced polymer (CFRP). CFRP is a polymer interwoven with fibres of carbon, which is 5-10μm in diameter. The mixture of these two materials gives an extremely strong but lightweight material, useful in building products from aerospace and automotive, to sports equipment and technology.
Fueling the world
The name carbon comes from the Latin carbo meaning coal, and until recently most of our energy was generated by the consumption of carbon through the burning of naturally occurring carbon-based fuels, or fossil fuels. When these fuels, such as coal, natural gas and oil, are burnt, the combustion reaction generates carbon dioxide (CO2).
CO2, produced by burning fossil fuels, is thought to be a contributor to climate change. Image: Pixabay
High production of the by-product CO2, and its release into the atmosphere, is considered to have a negative environmental impact and is thought to contribute to global warming and climate change. Fossil fuels are not a renewable resource and supplies are expected to diminish in the next 50-100 years.
Consequently, there has been a movement towards more renewable energy, from wind, solar and hydropower, driving a move towards a low-carbon economy. These energy sources are generally considered to be better for the environment, with lower amounts of CO2 being produced.
Chemical engineer Jennifer Wilcox previews some amazing technology to scrub carbon from the air, using chemical reactions that capture and reuse CO2. Video: TED
In this strive for a low-carbon economy, new technology is being used that prevents the release of CO2 into the atmosphere in the first place. Carbon capture and storage (CCS) takes waste CO2 from large-scale industrial processes and transports it to a storage facility. This CCS technology is one of the only proven, effective methods of decarbonisation currently available.