Johnson Matthey has been involved in research to understand the role of carbon in palladium catalysis.

According to Science, the nature of working with heterogeneous industrial catalysts complicates the investigation of their mechanisms with surface science techniques.

The limited number of methods that can monitor hydrogen can also present a problem but Teschner et al. have combined two techniques that overcome some of the limitations.

In situ photoelectron spectroscopy and prompt gamma activation analysis enable researchers to study the role that the subsurface carbon and hydrogen play in the selective hydrogenation of alkynes to alkenes in palladium.

Research into the roles of subsurface carbon and hydrogen in palladium-catalysed alkyne hydrogenation revealed that alkynes can be selectively hydrogenated into alkenes on solid palladium catalysts.

To make this happen, a strong modification of the near-surface region of palladium, in which carbon occupies the interstitial lattice sites, is needed.

Detre Teschner of the Fritz-Haber-Institut der Max-Planck-Gesellschaft indicated that the population of subsurface sites of palladium, by either hydrogen or carbon, governs the hydrogenation events on the surface.

Source:

The Roles of Subsurface Carbon and Hydrogen in Palladium-Catalyzed Alkyne Hydrogenation, 04/04/08
http://www.sciencemag.org/cgi/content/abstract/320/5872/86

Science
http://www.sciencemag.org/content/vol320/issue5872/twis.dtl