Dislocations as Active Centres in Heterogeneous Catalysis

MUCH work has been carried out in recent years on the relation of heterogeneous catalysis to point defects in solids or to semiconductivity. We have found an example of catalysis in which dislocations play the part of the active centre in the case of copper for the decomposition of diazonium salt (Gattermann's reaction). A sample of copper, free from point defects and containing dislocations only, is obtained by annealing the cold-worked sample in an appropriate temperature-range. The necessary data on annealing, a twisted sample, as given by Boas 1 , are summarized in Fig. 1.