No. 91201 INTRODUCTION Although heterogeneous catalysts are essential in numerous chemical processes, the exact structure of the active phase remains unsolved in many cases. In order to understand the structure-reactivity relationships, a relevant approach consists in examining the catalyst while operating. This so-called operando approach has recently attracted a fast growing attention and was applied to various spectroscopic techniques: IR, Raman, Electron Paramagnetic Resonance (EPR), UV-visible and X-ray Absorption Spectroscopy (XAS). However, it generally appears that one single spectroscopic technique does not make it possible to spell out the complexity of the catalytic process. Therefore, the direct coupling of complemen- tary in situ or operando techniques offers a multiple and simultaneous characterization of a working catalyst for a much better understanding of the catalytic process. Such studies request the use of a single spectroscopic reactor fitting the combined peculiarities of catalysis and the involved spectroscopic techniques. The coupling of XAS and Raman spectroscopy was successfully performed in a commercially available operando chamber to supplement our previous Raman studies on TiO 2 supported oxomolybdate catalysts. 1 The investigated selective oxidation of methanol is both a major economic reaction for vaporization of biomass by- products and a probe reaction broadly used to study redox and acido-basic properties of bulk and supported oxides. EXPERIMENTAL The catalysts were prepared by incipient wetness impreg- nation of an ammonium hepta- molybdate solution on pure anatase TiO 2 commercially available by Sachtleben™. The specific area of the support was 93.5 m 2 .g -1 after a pre-treatment (rinse with distilled water and calcination 5h at 500°C). The concentration of the impreg- nation solution was adjusted in order to reach a molybdenum Coupled XAS-Raman Operando analysis of TiO 2 supported oxomolyb-date catalysts in methanol conversion Camille La Fontaine, Françoise Villain, Valérie Briois Synchrotron SOLEIL, L’Orme des Merisiers, Saint-Aubin, BP48, 91192 Gif-sur-Yvette, France Xavier Sécordel, Anthony Yoboué, Elise Berrier, Sylvain Cristol UCCS, Unité de Catalyse et de Chimie du Solide, Bât C3 Université des Sciences et Technologies de Lille, 59655 Villeneuve d’Ascq Cedex, France Figure 1. Operando Raman-XAS coupling setup.