2. Catalysis

Catalysis helps to save energy and to produce less waste. Hydrogen will possibly be the energy carrier for the future, but it will not replace oil before several decades so the efficiency of the catalytic processes in petroleum refinery and petrochemistry still has to be improved. Numerous physical techniques are being used to follow catalytic processes. The samples can be subjected to several probes: electrons, photons, ions, neutrons; and various fields can be applied: magnetic, electric, acoustic, etc. Apart from the basic catalyst characterization, the various methods aim to observe surface species (intermediate species are much more tricky), the reaction products, and the influence of diffusion. Coupling of two, three, or more techniques is now common and very powerful. The biggest challenge has always been to perform measurements during the reaction, the term in situ being sometimes replaced by the more recent one operando, when the catalyst is under working conditions of pressure, temperature, flow, and avoiding diffusion limitations.