Selective Catalysts

Most of the industrial chemical transformations to prepare important building blocks are conducted at medium to high temperatures and pressures. Catalysts that are used to make these processes feasible have to be not only active, but also stable under reaction conditions for extended periods of time.

Several mechanisms of deactivation are possible, the most severe involving the loss of active surface area either by particle agglomeration (sintering or ripening processes) or by poisoning by intermediates or byproducts. Reducing catalyst deactivation is therefore as essential as obtaining active catalysts.

The study of catalyst stability is central in the Cargnello group. Strategies for avoiding catalyst deactivation include the formation of core-shell structures, where the core active material is protected against sintering by a porous, thermally stable shell. Alternatively, the composition of the nanoparticles can be tuned so that poisoning and byproduct deposition is limited. Heterostructures, where two active compounds are placed close to each other, are also of interest for studying the physical interaction between two materials and their effect onto the final performance of catalysts.