Sir John Meurig Thomas obituary

Philip Ball
·5-min read

John Meurig Thomas, who has died aged 87, exemplified a generation of British chemists who linked a vanished era of industrial prowess and innovation to the cutting edge of atomic-scale nanotechnologies. His field of expertise, solid-state catalysis, underpinned the growth of the fine-chemicals and petrochemicals industries, but now may hold the key to sustainable green technologies for energy and chemical processing.

As well as making world-leading contributions in that area, Thomas was celebrated for his passion for communicating science to a wide audience. As director of the Royal Institution in London, he co-presented the 1987 Christmas lectures, established in 1825 by Thomas’s idol Michael Faraday, and his knighthood in 1991 was “for services to chemistry and the popularisation of science”. He was not only a scientist of international renown but also a writer of great flair and eloquence.

From 1978 to 1986 he was professor and head of the department of physical chemistry at Cambridge University, before being appointed director of the Royal Institution in 1986. The RI then still housed its own research lab, the Davy-Faraday research laboratory, which focused on Thomas’s field of inorganic chemistry and where he became Fullerian professor of chemistry.

Thomas studied processes of catalysis – the speeding up of chemical reactions – taking place on the surface of inorganic crystalline solids. He worked in particular on a class of materials called zeolites – aluminosilicates in which the crystal structure contains channels (micropores) and cavities comparable to the size of molecules. Because these channels will only admit molecules that are small enough, they are commonly known as molecular sieves. This selectivity, combined with their ability to catalyse reactions that break apart or rearrange hydrocarbon molecules of the sort found in crude oil, makes zeolites invaluable in the petrochemicals industry.

At Cambridge and the RI, Thomas helped to develop new techniques, both experimental and computational, for investigating the structures and properties of zeolites and other microporous materials. He had a keen eye for the possibilities of new methods, pioneering a technique called magic-angle spinning that overcame the limitations of nuclear magnetic resonance (NMR) for studying the structures of solids.

At the RI, Thomas worked alongside Richard Catlow, now at University College London, and he was succeeded as RI director by Peter Day. All were chemists who built on a long British tradition in inorganic chemistry, harking back to the crystallographic work of William Bragg (director of the Davy-Faraday lab from 1923 to 1942) and his son Lawrence in the 1920s and 30s, and the postwar work on inorganic catalysis by the Nobel laureate Geoffrey Wilkinson.

Thomas’s fundamental studies in the structure and behaviour of solid catalysts led him towards a deep interest in methods for probing chemical reactions in unprecedented detail. He was among the first to appreciate that X-rays, first used by the Braggs to study crystal structures, might be used in a new kind of microscopy that produced images showing individual molecules with atom-scale resolution. So-called synchrotron sources and free-electron lasers, which produce extremely intense X-ray beams, are now realising that vision.

Thomas also anticipated the use of laser and electron beams to create “movies” of chemical reactions as they unfold in a fraction of a billionth of a second – a technique developed in Nobel-winning work by his friend the Egyptian chemist Ahmed Zewail, of the California Institute of Technology. In such ways Thomas showed himself, even in the late stages of his career, alert to innovations on the horizon.

He was keenly aware that at the RI he was taking on the mantle of both Faraday and his mentor Humphry Davy. Thomas wrote extensively about both men, notably in his 1991 book Michael Faraday and the Royal Institution: The Genius of Man and Place. His 1986 lecture The Poetry of Science, part of the RI’s Friday Evening Discourses, captures this spirit, closely attuned to the romantic inclinations of Davy. In his Christmas lecture he quoted Ralph Waldo Emerson: “Atom from atom yawns as far as moon from earth, as star from star” – “a tremendous insight”, he added, “into the way nature is built up”.

Proud of his Welsh heritage, Thomas was born near Llanelli, Carmarthenshire, and brought up in a mining family in the Gwendraeth valley, the son of David and Edyth. Following Gwendraeth grammar school, he studied chemistry at the University of Swansea and, after a brief stint at the UK Atomic Energy Authority (the first of his 1,200 or so published articles, in 1959, was The Chemistry of a Nuclear Reactor), took positions at the University of Wales in Bangor in 1958 and then Aberystwyth, before his appointment at Cambridge in 1978. He was made a fellow of the Royal Society in 1977.

After leaving the RI in 1991, Thomas spent three years as deputy pro-chancellor of the University of Wales before becoming master of Peterhouse, Cambridge. He retired in 2002, after the death of his first wife, Margaret (nee Edwards), whom he had married in 1959.

Among his many awards, the 2015 Ahmed Zewail prize in molecular sciences must have given him particular pride. Thomas’s 75th-birthday symposium in Cambridge was attended both by Zewail and by the German chancellor, Angela Merkel, herself a former chemist, whose husband, Joachim Sauer, studied the interpretation of NMR applied to zeolites.

Thomas combined great charm – his rich, lilting Welsh tones were hard to gainsay – with driving ambition. Conscious perhaps of his own humble start, he never forgot how hard Faraday had to work to earn a place in science. He made no secret of his own hopes of winning a Nobel, and his name would surely have been discussed in Stockholm. Perhaps this revealed how Thomas, however forward-looking about the possibilities of science, nevertheless could not abandon a notion of the heroic lone scientist that harked back to Davy and Faraday.

Thomas was a strong supporter of the Labour party and during his directorship the Royal Institution hosted the launch of Labour’s science policy under Neil Kinnock.

He is survived by his second wife, the Egyptian chemist Jehane Ragai, whom he married in 2010, and his two daughters, Lisa and Naomi, from his first marriage.

• John Meurig Thomas, chemist, born 15 December 1932; died 13 November 2020