Hydrogenation of CO and CO2: Contributions of IR operando studies

The hydrogenation of CO and especially that of CO2 will raise increasing interest as means to manufacture base chemicals and fuels. This contribution discusses some of the aspects of CO and CO2 hydrogenations that can be unravelled using in situ and operando FT-IR studies. This non-exhaustive mini-review gives a limited set of ex-amples taken over Co-, Rh-, Ni-and Ru-based heterogeneous catalysts of the type of information that can be obtained through operando IR studies. It stresses the need to carry out quantitative IR studies, if relevant con-clusions are to be drawn. Some limitations and pitfalls of diffuse reflectance spectroscopy are also discussed. The possibility to carry out quantitative DRIFTS studies is demonstrated on several examples. The potential of IR spectroscopy to unravel the properties of CO2 trapping-methanation materials is briefly discussed.