Wyn Roberts was a pioneer of modern surface science. He carried out seminal work exploring gas-solid interaction and pioneered new techniques in spectroscopy.
Meirion Wyn Roberts was born in the village of Rhydamman (Ammanford) in Dyfed, and educated at the Amman Valley Grammar School, where he was a popular and fleet-footed wing three-quarter and a sprinter well-known among his contemporaries in the schools of South Wales. It was as representatives of the Carmarthenshire Schools athletics team, competing in the Welsh championships, that we got to know one another in 1947.
He took an honours degree in Chemistry at the University of Wales, Swansea then undertook research for his PhD under Keble Sykes (obituary, 18 June 1997) on the intricacies of the surface properties of the nickel films deposited by the decomposition of nickel carbonyl, a phenomenon discovered by Ludwig Mond, the founder of ICI. He pursued postdoctoral work in the group led by Professor FC Tompkins at Imperial College, London, 1955-57, before his appointment as Scientific Officer at the National Chemical Laboratory (1957-59).
His great promise as a surface scientist prompted the late Professor Charles Kemball to recruit him as a lecturer at Queen's University, Belfast (1959-66). There he carried out outstanding work on chemisorptions of gases on metal surfaces, on the work function of metals, and the physical chemistry of metallic oxidation. This led to his appointment as the Foundation Professor of Physical Chemistry at the University of Bradford, 1966-79, where he did work of seminal importance in the elucidation of gas-solid interaction, and where he pioneered many new techniques to address the questions that arise during such interactions.
Two such techniques were electron spectroscopy for chemical analysis (ESCA), later refined and renamed as X-ray induced and ultra-violet-induced photoelectron spectroscopy (XPS and UPS respectively), and low-energy electron diffraction. So good was his experimental prowess that the Vacuum Generators Company in East Grinstead manufactured one of the first (and best) commercial photoelectron spectrometers based on his original creation. This was a great success nationally and internationally, and was used by scientists the world over.
He was appointed Head of the Department of Physical Chemistry at University College, Cardiff (1979-88); deputy Principal, University of Wales, Cardiff (1989-92) and Head of the School of Chemistry (1988-97). On retirement in 1998 he became a Research Professor.
One of his most outstanding early contributions – described beautifully by him in his Tilden Medal and Prize Lectureship of the Royal Society of Chemistry in 1976 – was to demonstrate that, when the diatomic molecule, carbon monoxide, is adsorbed by metals such as iron cobalt, ruthenium or nickel, it does not form surface layers of metal carbonyls, as had been predicted, but, instead, the molecule dissociates into its component atoms, which are each strongly bound to the underlying metal. This aspect of his work did much to elucidate the mechanism of the Fischer-Tropsch process, discovered in Germany in the 1920s and still the basis of the production of hydrocarbons (for transport and heating) from the gases generated in the partial oxidation of coal or biomass.
For 20 years or so his research was focused on the identification of short-lived (transient) oxygen species at metal catalyst surfaces, especially in processes involving the oxidation of ammonia. This aspect of his work elicited praise from the German Nobel Prize-winner, Gerhard Ertl, and many others.
Because of his distinction in research, and also his lucidity as a lecturer, he was appointed visiting professor in many overseas universities and academies, included Xiamen in China and University of California, Berkeley. Numerous collaborators, especially a group of gifted scholars from Northern Ireland, went on to hold distinguished posts in several countries.
He had strong links with Dr Hajo Freund, now a Director of the Fritz Haber Institute, Berlin, and their much-cited 1996 joint paper on the use of carbon dioxide as a feedstock was well ahead of its time. In a masterly survey completed only a few weeks before his death he revisited this and a related topic in an article entitled "Low energy pathways and precursor states in catalytic oxidation involving water and carbon dioxide at metal surfaces", soon to appear in the journal Catalysis Letters.
Of his numerous articles, reviews and books, two stand out: his acclaimed 1978 OUP monograph with CS McKee on The Chemistry of the Metal-Gas Interface, and his 2008 text with his former student and colleague PR Davies on Atom-Resolved Surface Reactions (RSC Press). As an author of readable textbooks he had the happy knack of prefacing his work with choice selections from other fields. In his book with Davies he reminds us of Theodore Roosevelt's remark: "It is not the critic who counts, not the man who points how the strong man stumbled ... The credit belongs to the man that is actually in the arena, whose face is marred by dust, sweat and blood, who strives valiantly, who errs and comes short again and again, who knows the great enthusiasm, the great devotion and spends himself in a worthy cause, who at the best knows in the end the triumph of high achievement and who at the worst, if he fails, at least fails while daring."
In addition to several prestigious awards – the British Vacuum Council Prize; the Royal Society of Chemistry Prize in Surface Chemistry and the AG Evans medal, for example – Roberts served on many influential bodies, including the Wool Foundation, the Science and Engineering Research Council, Chemistry Committee and the University Grants Physical Sciences Committee. In his dealings with young and old, with the distinguished and with novices, Wyn Roberts behaved with gentlemanly decency and generosity of spirit. Surface scientists and many others will mourn his passing, and remember him with deep affection.
Meirion Wyn Roberts, chemist: born Ammanford 1 February 1931; Foundation Professor of Physical Chemistry, University of Bradford 1966-79; Professor (later Head of Department) Research Professor, University of Wales, Cardiff, 1979-97, Deputy Principal, 1989-92; married 1957 Catherine Angharad Lewis (one daughter, one son); died Cardiff 5 March 2014.