The development of existing technologies and the creation of new ones with reduced environmental impact strongly depends on the fabrication of new materials with specifically tailored and controlled properties. In this respect, the comprehension of the structure of materials plays a fundamental role in providing the crucial piece of knowledge necessary for understanding their properties and, in the case of artificially engineered materials, the experimental confirmation of theoretical predictions. Complementary to static structure determination is the study of the structure and morphology of materials during their synthesis or under realistic working conditions. These in situ studies make it possible to study all of the steps necessary for the production of a particular material and to determine the intermediate compounds which are formed. They aid also in the optimisation of productivity and to reduce degradation. The ESRF has always been at the forefront in this field thanks to its beamlines, which take advantage of the high quality X-ray beams, and to the development of new methodologies and to the continuous improvement of the available sample environments.

In this chapter we present several highlights from ESRF and CRG beamlines. They deal with different scientific cases ranging from the structural characterisation of nanomaterials, either natural as in the case of sea-shells or artificial such as SiGe quantum dots, to the correlation between crystallographic structure and electronic or magnetic properties. Several contributions are about in situ and real-time studies of different kinds of reactions, mainly catalysis studies. They provide, via X-ray diffraction, information revealing the formation of intermediate phases which turn out to be crucial for the reaction mechanisms. Similar results are presented in the case of electrochemically-controlled deposition, highlighting the role of the applied potential which results in different growth modes.

The year 2012 has been an important one for the beamlines of the Structure of Materials Group. The designs for UPBL1, the upgrade of ID01, UPBL2, the upgrade of ID15, and the upgrade of ID31 have been completed and construction will start during 2013. All the beamlines have expanded the scope of the sample environments and ancillary tools that can be installed on their instruments so as to increase the possibilities for controlling the sample conditions. In addition, ID03 has installed a new diffractometer, which makes it capable of carrying larger and heavier sample environment setups. ID11 has further strengthened and standardised its methodologies for high-energy nanocharacterisation providing direct mapping with a resolution better than 100 nm or the possibility of studying samples with volumes smaller than 1 μm3. X-ray diffraction computed tomography has been a major breakthrough at the high energy beamline ID15. In experiments where a time resolution of several minutes is acceptable, this technique may provide much more physical and chemical information than the conventional tomography technique. Furthermore X-ray diffraction and conventional computed tomography can be combined since they are installed on the same instrument. Last July ID32 was definitively closed for operation and dismantled during the summer. Its high energy X-ray photoemission spectrometer will eventually be installed at a new beamline. The electrochemistry laboratory has been temporarily relocated to ID03, waiting for a location in the new building. In 2013 UPBL1 will begin its construction phase while the new powder diffraction beamline will be constructed at the ID22 location. All the personnel of the different beamlines will continue working to improve the instruments and to develop new methodologies to promote science and better serve our user community.

R. Felici