This study brought together advanced spectroscopy (EXAFS), microscopy, theory and catalyst synthesis to solve a key problem. The use of gold as a catalyst for acetylene hydrochlorination has been known for more than 30 years. However, previous ex situ studies created nanoparticles that clouded the scientific picture of what was really occurring.
In situ studies at Diamond Light Source showed that the active species was highly dispersed gold cations with Au(I) being the predominant active species, and this was confirmed by microscopy.